Other than bulbs (327), I don't recall replacing parts of the switch. Remember replacing the entire switch assembly. Depending on the switch, a rather laborious job at times. The harness' were exquisitely hand wired. KSC Test Conductor Units were huge by today's standards and loaded with those switches. Eventually Shuttle brought in new comm systems and eventually all Apollo era (and before) equipment was replaced. I do remember the last units replaced may have been the audio 4-Wire comm panels.
This is a MSC (Master Specialties Corp) Series 10 "Twist Light". Can be an indicator or a act as a push button switch as well. The face can be split from 1 to 4 individual segments. Can attach a switch block for 2 to 4 switches, maintained or momentary. Very common in G.E. nuclear plant control rooms. Still available new.
As an instrumentation engineer in the 1970s, I used to specify those switches. Used them for a control panel at the IBM Poughkeepsie physical plant. Also spec'd them for use in jet engine test cells/hush houses at Naval Air Rework Facilities and Top Gun near El Toro. They were more expensive than competitive switches by (say) Square D. But they were also more customizable.
I salvaged a bunch of those, long long ago. The rear snaps off to allow for no switches at all (indicator only), momentary or alternate-action switches, from 1 to 4 SPDT micro-switches. Like all military/avionic displays, the lamps are front-replaceable and there are 2 lamps for redundency/safety. There's no built in lamp-test (some are push-to-test). Little silicone hats color the flange-base bulbs.
Yea, that switch module was 4PDT, and Push-On, Push-Off, you could get a diff module that was just momentary... Close on Push, Open when released... I always love the 'positive click' during actuation.... very satisfying ....
The same switches were used in the 1980's on offensive avionic panels in B-1B and updated B-52 bombers. I tested the panels at Boeing before they went into the aircraft. Always enjoyed pushing the "LAUNCH" button.
Thanks for showing this to us, I had no idea. The awesomeness of the Apollo program is palpable even in this lowly ground control switch! And now I know I NEED one...
@@mrnmrn1 I wish, but these beautiful switches are way expensive! Looking how involved they are, they probably also were quite expensive at the time too!
@@CuriousMarc After some digging around, I found a catalog to try and make some sense out of the cryptic (but necessary) part-number scheme. Pretty amazing product! flamecorp.com/PDF/Safran-Electronics-Defense/10E-H%20Series.pdf
Back in the 70s I worked on control panels using these type of switches. They were difficult to fix when broken. This usually happened when the switch was worn from many cycles. Nice memories.
At work we had a big box of similar modular switch assemblies that were salvaged from some old vacuum gear, that we used in all sorts of internal prototypes and lash-ups. We never bothered to remove the old decals so the buttons and lamps never said what they actually did. Our favourites were the buttons that were simply labelled "Baffle".
I've seen the second bulb in the indicator division used as a backlight for low-light applications. The backlight was often dimmable for the entire switch panel and was a different color than the "active" colors.
Pretty standard in industrial control to have redundant lamps for high priority indications. Not so common to have provisions for redundant power sources.
@@NiHaoMike64 The other "fault" was that both pilots was distracted with trying to get the bulb out to check it. There was no one flying the plane. Very tragic, even a sequence of events brought down the plane. If any had not occurred, the plane would have landed intact and at its destination.
My company used tons of those "back in the day" and they were VERY expensive. And since we were not not smart enough to run the bulbs at a slightly reduced voltage, they ate bulbs at a high rate. Bulbs were expensive and Master Specialties never made it easy to remove the lenses. It's jewelery and costs like jewelery.
It's the tiniest thing but I have to appreciate that this seems to easily be maintainable while it's not only installed but also powered. The common making contact before anything else is the main thing that suggests as much to me, one of those "someone really cared" sort of details. I love switches. It sounds silly when I say it out loud but it's true.
Having seen these in use, what they did for dead bulb detection was use a ?47 ohm 2W resistor to feed the lamp in the "off" condition, so that it would have a slight glow. No glow = lamp open
I believe there is a little C-frame type tool for popping the head out for bulb-swap sorta like a chip extractor, but more robust and with springsteel ends. .
Marvelous stuff Fran! My studio at the Beeb had a similar switch, though from a different manufacturer. Being modular you could have the same front end indicator with different switches, so some were not latching, and you could also make them change over. The ones we had didn't have that clever rotating action. We had a special pair of tongs to get the bulb assembly out. The front slid off, then you could get the tongs down the sides to unlatch the assembly and pull it out. The bulbs had the same coloured caps, and the legend was on a piece of transparent celluloid, done with Letraset. The bulbs were 27V but run at 24V, and we even had special tongs for pulling them out! The great thing about them being modular was you could make pretty much any sort of switch you wanted. Their main use in the studio was to operate the internal video routing. The push buttons worked a big relay matrix, which in turn operated video and audio switching. It could be a nightmare to troubleshoot. The latching mechanisms were so clever. Those rollers could be different shapes so you could have 1 or 2 micro switches NO and the other NC. And since they were operating realays in the racks in another room, the lights were switched separately. Lots of long runs of multi core wiring.
I owe you an apology in that when I saw a during of 20 minutes I thought that is pretty long for just an illuminated switch, but in fact I found the entire video riveting. Thanks for posting it.
An engineer's spare-parts "junk box" is always filled with precious relics. All sorts of mysterious and unbelievable, clever and curious, useful or useless things. It takes a lifetime to collect these lost arts since none of them ever appear especially interesting or valuable until they just don't make them anymore.
This is a blast from the past for me. In the early 80s I was working in the UK at a USAF satellite communications station at RAF Croughton and the AN/FSC-78 master control panel used those switches for status and control of the transmitters and some ancillary functions. The control panel interfaced to the station hardware through a control box (3'x3'x4' lwh) that was 54 series TTL.
Likewise, at RAF Fylingdales in north Yorkshire we used these by the by the bucket load. I still have a few as souvenirs when our section was decommissioned. They never went wrong. The bulbs were all 28 volt 40ma under run on 24v.
I share your interest in illuminated indicators. I was a military avionics tech in the late 1960s, aircraft cockpits tend to be full of these types of indicators.
I’m surprised you didn’t have the switches hooked up to toggle the lamps with each push (and some litho inserts) to say [green] FRAN [red] LAB, FRAN, LAB, FRAN, LAB…
Fran, you are AMAZING!! I just discovered your channel and you have already blown our minds with your incredible videos about the Apollo launch vehicle ejectable film canisters, the F1 engine design, and the brain-bending design of the Mission Control video displays, and right now we are watching your exploration of the Mission Control panel switches. You have made my day!! What a terrific communicator you are!!? Your extraordinary knowledge and enthusiasm are as infectious as they are impressive. Congratulations!!! My wife works in science education here in Australia and she is definitely recommending your channel to her colleagues at her school. Hats off! You are my new favourite RUclips channel and I'm already getting RSI from sharing your videos to my friends! Love your work, and so excited to explore all your wonderful videos. Live long and prosper!
Agreed, top/bottom split illuminated switches in COLORS are kewl! Move the color caps and use one lamp at a time for either color top independent of either color bottom!
While serving in the US Navy as an Electronics Tech we had crude automated test suites for a sophisticated air search radar set. It used 8 track tapes to load test programs and the control panel had several of these types of switches. They always had a positive feel to them when used and having a light inside confirmed your selection when using the switch.
I love how mechanically over engineered everything from the slide rule era is!!! I bet that thing would last 100 million cycles. (Edit, I am being hyperbolic with the 9 figure cycle count, but I would bet that thing outlasted any system it was used in)
@@radimkolar2270 I did think about that right after I wrote this. I was being a little hyperbolic with the 100 million, but I bet they mechanically outlasted anything they were ever put in. The late 1950s and 1960s brought us some great advancements in plastics with impressive mechanical properties. I imagine that ratchet is some flavor of HDPE possibly impregnated with a lubricant to help with the sliding wear. I have a reasonable eye for this stuff. For 20 years my job has been mechanical strength analysis simulation and testing. I ensure parts are strong enough to live through their expected life. We use a 2x factor of safety when back then, without the insane computer simulation we have today, they were more like 5-10.
I saw this 2 years ago and just had to come back here. I used a number of these switches in the mid-70's in my electronic hobbyist craze. I used them to make an illuminated control center for my stereo system and speaker switches with relays. I got these at electronic surplus places in Minneapolis, one was Honeywell Surplus. This vid brought back a lot of memories
I remember watching Apollo missions on TV when I was a kid. I was in the second grade when the first one made it into space. It is amazing what they accomplished with technology that probably wouldn't even have enough computing power to play an iTune.
How about a switch labeled "ENGINE START" that launched many a Delta rocket through the '70s and into the '90s. I have the actual switch that did that.
When I was in high school, we had TONS of these in our electronics and robotics classrooms, all new in box. They were most likely donated from Rockwell, Allied Signal, or Bendix in the 80s... I helped take most of them to dumpsters when the school was remodeled in 1996. We had no idea just how special they were!
I used to build panels up at Sikorsky' Aircraft in the test center and used different bulbs depending on the voltages used. We used similar Unimax switches and when you pulled out the plastic front button you can slide out the plastic panel out to the side. What I would do is in grave the back side of front plastic and fill the engraved area with a black grease pencil or lacquer stick then polish the surface clean. So when the lamp lights you can read what the switch said. Aircraft uses the same type of switches depending on the age and type of plane. I used to work on Jets in the Navy so we would be replacing bulbs often. having 4 bulbs would be for redundancy so if a bulb was out the other would still show the status of the switch or it could actually indicate 4 types of status colors depending on the rubber boot. They also make LED lamps that fit in thoes lamp holders. Those switches are cool to build things with. The hard part was, the square hole was hand filed to fit the switches just right. Have fun with them.
From at least the ‘60s, this type of control was used on many military panels, especially in dedicated “positions,” vs. stand-alone gear where the sky-high cost was prohibitive. For example the AN/FLR-9 “elephant cage” antenna system used them to allow operators to select a beam direction from among several assigned for a given mission. Snazzy indeed! Still today those who build their own panels would like the same degree of snazziness, but for practically no cost, and it now can be done. Start with the same size tile, drill some holes in it for pockets to hold LEDs, glue it to a rear tile slightly larger vertically (but not horizontally to allow ganging), cut the panel hole to allow the front tile to penetrate, and screw the rear tile to the rear of the panel. For the switch, bring some narrow metal (bare wires?) to the front for touch pickup; the 60Hz buzz picked up can be used to activate a 1-bit logic switch for as long as the contact is touched. Alternatively, pick up skin resistance. From that one switch you can of course feed any desired digital circuits, including debounce, finger pressure, or whatever to achieve the look and feel of the original article. You could even use the pickups to feed a microcontroller to scan an array of tiles saving building the circuitry for each switch. Now everyone can have switch snazziness without all that original mechanical stuff. Another reason these switches were mainly limited to panels is that they were so hard to push that any small equipment would just slide off the shelf and fall on the floor!
Nicely done. Thanks for taking the time to share the joy of this gem. There aren't enough beautiful tactile or mechanical switches left in the world. I'm actually in the process of having to design a new bezel from spun up acrylic unfortunately as no light pipe makers do anything even remotely nice over about 5mm these days.
They make a tool to pop the lens out for bulb changes. Aviation still uses similar switches, for many different uses, but the flashing warning light is the most prevalent. I have run across older aircraft that still uses switches very similar to the one in the video. As time went on the switch mechanisms got more integrated, and then smaller. Newer aircraft are moving to different methods, especially those built in the past decade, but due to the way regulations work, older parts are still used even to replace faulty switches, rather than just install a newer style.
In the early 70s I worked in the center that controlled electric power transmission throughout NorCal . These indicators were set up so they glowed white in normal condition and flashed red in off-normal condition. Two lamps for each condition. The off-normal lamps were energized through an interrupter to provide flashing. AND, the off-normal lamps had little red booties on them for coloring the light.
Love your work, Fran. Much of the technical stuff flies over my head at the speed of light, but still I find it all fascinating! Your enthusiasm is extremely contagious, thanks!
These switches were also used in power plants built in the ‘70s. They were used in early multiplex equipment. Useful for operating remotely located equipment. Ours was replaced after 30 years when the spare parts were hard to find in the primary market.
7:00 as soon as you said those color filters were flexible rubber, I thought of the semaphore I had for my Lionel train layout back in 1965. The semaphore blade uses red and green lenses made of that same flexible transluscent rubber.
Thanks for this trip down memory lane. I haven't seen these since the mid 1980's when we used a lot of them at a big DOD contractor. They were really expensive, but Mil-Spec, so I've never really seen them outside of DOD stuff. The nicest part was we could just stock all of the individual pieces and easily configure them on the spot. In production the graphics were outsourced, but in the R&D labs we could pretty easily print our own or use rub-on letters.
Used lots of these in the Navy, for Gun and Missile Fire Comtrol Systems. Back in the day, late '60s early '70s, a lot of the consoles had these types of switches or were very similar. when you had to 'man' a console the first thing you did was hit the lamp test switch, to ensure all bulbs were working. There was a master dimmer control for all the bulbs, 90% of the second bulbs were redundant, however, in some cases, the second bulb had a colored lens in front of it. to show the status of the switch's function. ie. white or red. the faceplates of the switches were engraved or had a silk-screened panel behind them. this showed the switch's function. I seem to remember the bulbs were #327s and hard to replace once the mechanics were removed we found a solution to actually removing the bulb, the Machinist Mates or Gunners Mates had an incredible substance called "Monkey S**T, put on the end of a pencil and it would adhere to anything. Big glob for pulling the bulb out, a small glob for inserting the new bulb.
I remember those switches, they were made by a number of companies and they were a pain. The lamps came in several voltages 6,12,24 and others, and the lamp covers came in a number of colors and there were various messages that went under the bezel, power, overtemp, etc. The switches came in a wide variety of combinations and some were just indicators. Oh I worked on multichannel, single channel, HF, VHF, UHF, Microwave, systems Radar, Krypto, military and after I retired civilian, it was amazing how popular and expensive those switches and indicators used to be.
Wow - talk about designing for maintainability... What a little work of art. It doesn't matter how deeply you dig into the 60's space programs, there's brilliant engineering everywhere. Great find and great video!
I love my NASA era hardware collection. We are just a few miles from Mission Control and I have a great collection of those type switches/indicators. The configurations were endless.
@ 14:50 "that's the wrong bulb" LoL - laughing with you, not at you. I've learned over time to check twice and replace once. You live longer that way. Good video.
Built like a tank. That's switch is a classic! Things were probably sealed a bit due to coffee & cigarettes constantly nearby. You could hook it up to switch on your garbage disposal... just a thought.
That's quite a switch. I wonder how label inserts would work, I suppose you could laser print something on transparency film and insert it. I recently went searching for some lighted rectangular switches-- not based on NASA consoles, because I can't say I knew much about them. But I worked with early computers and similar sort of rectangular buttons were common on computer equipment, such as IBM tape drives & the like. Labels like, Run, Stop, Reset, Load, etc.. thinking I might want to create a retro looking panel for some project. Found that you can find modern versions of these sorts of rectangular switches on eBay in various colors, in both momentary and latching, and can put your own insert in for the labeling. Nothing as nice as the one you show here though, no doubt making a switch like that today would be prohibitive.
I have seen a similar switch in a piece of equipment i tore down (it was a "Spectrascope 8000" made by LABEN, in Italy in the '70s). It was manufactured by Micro (Freeport, Ill, USA on the label) and it has a very similar, if not identical, construction to the one in the video! Same 4 (with the coloured rubber bulb cover) incandescent bulbs and switch mechanism. It was used as the main power switch in that instrument. Thanks for showing these Apollo Era pieces of equipment, fascinating stuff was made back in those days!
I built a lot of those consoles back in the day, with a lot of those lighted switches. Because they were actual incandescent bulbs, they used to raise hell with power on current surges.
These switches are 2 parts. The top lamp is the “command”. The lower is a “report”. So you had confirmation from eg from a downlink. We had tons of these in our equipment. They ran 28V bulbs x 4. We can do lamptest on a button. Usually driven by ULN2003s. Neat find 👍🏻
This type of switch is exactly the same, it is identical to the ones used in the planes of the 60s, 80s, and 90s of the last century. If I remember correctly the manufacturer was KORRY and by the way it was proof of all kinds of misuse and abuse, they were very resistant mechanically speaking. When they failed, they were due to a burned-out lamp or a defective microswitch, in which case the entire set of switches had to be replaced but not the actuator module or the push button. To replace a burnt bulb the task was so simple that the flight crew was able to perform it easily. Nice piece of equipment. The p/n of the bulb was 328 miniature lamp of 28 volts.
It's gloomy outside this morning and this video is great. Anything from Apollo era mission control is worthy of breaking down. The small yet significant displays or buttons show the amazing and creative engineering. Pioneers.
There were quite a few contractors that built such things in that area at one time-- TRW in Redondo Beach, some stuff in El Segundo, Inglewood, etc., all not far from Gardena. Fairchild was over there somewhere too at one point.
Yes they are great PBI's. I have many of them, no doubt enough to make a complete Keyset Comm module. Very ingenious Push Button indicators. Very versatile. Great video!
Very cool! Great switch and indicator engineering! Find me a switch today with this much functionality and built for ease of maintenance and longevity.
Wow! Thank you, Fran! I am aircraft engineer (Tashkent, Uzb.). Never deal with mission control equipment - techniclly know, practiclly never touch. You are so cool!
This as commonly known as a PBI (Push Button Indicator). Before I retired, I was a Command and Control SW Engineer in the MCC at Johnson Space Center in Houston. Part of our task was to replace PBIs with touchscreen widgets using xMotif and C/C++. It was a fun project but somehow not as satisfying as the click of a working PBI.
I had no idea that these were special. My dad used to buy them at state surplus by the boxful. He even used them all over the dashboard of a kitcar he built in the early 70s. I now have his boxes of them, LOL. He taught me how to open and service them, change bulbs, etc. Some are momentary, some latch. I love that you got one of them (if I had only known you were looking) :)
Yay! My very first real engineering job in the 80's, I worked on annunciators for major aerospace project at megacorp. Long list of requirements had to be met. Brightness, temperature, force, feel, etc.
CM344 is a 10V lamp, probably chosen for its 50,000 hour life rating. See stevenengineering.com/Tech_Support/PDFs/27INCD.pdf. Chicago Miniature Lamp has been around for decades. Amazing that they still make incandescents.
I went down a rabbit hole with those switches. The Twist-Lite series 10 switch is still available. Master Specialties moved to Costa Mesa and was acquired by Eaton, becoming Eaton Aerospace Controls Division, and more recently by Safran. Flame Enterprises at flamecorp.com has been a distributor since the MSC days and has a great collection of catalogs showing all the options.
Picked up some of these a few years ago. 70s vintage :) Came complete with #327 lamps (funnily enough, the same type as suggested in the LT1037 datasheet, for constructing a Wien Bridge Oscillator!) I belive the mechanism for accessing the lamps is deigned so that they can be changed without accidently pushing the switch. There is somthing very satisfying about high-quality illuminated switch goodness :D
These are quite commonly used in the petrochemical industry and in power plants, at least they used to be. As far as replacing the lamps, always test the lamps, not just by their ohmic value but actually pass voltage through them (usually 28 volts) to avoid frustration.
In the words of Gene Cranz "Tell me this isn't a government operation ?" "Yep, the illuminated switches are supplied without illumination bulbs." Stoked up for you Fran. I'm utterly jealous. :)
I'm guessing the reason the bulbs weren't supplied is so they wouldn't have to have separate part numbers for different voltage bulbs. By letting the customer supply their own, they customer chooses the voltage/brightness/bulb life.
If anybody is curious about what happened to that company from what I can find apparently went something like this Master Specialties Co. > Around May 1985 they were absorbed into Eaton and became Eaton Master Specialties Co producing cockpit buttons and what not >2014 Safran acquired Eatons Aerospace division. So its now owned by the French.
Fran, there was a great surplus electronics store in Philly I used to go to in the early 1980s. Fertiks, on Ella St in the NE section. Hours were Thursday evening and Saturday. I think it's long gone now but they had a lots of switches like that and a huge selection of transformers, in quantity in many cases. The claim was you go in there and specify the secondary volts and amps you need and he had a transformer that would fit the bill. In addition to the old Philco plant at C & Tioga, the RCA commercial electronics and broadcast products factory was right over in Camden. I'm sure most of the great surplus came from those factories. There was also H&R which I think downsized and moved to NJ, but Fertik's was much better IMO.
What a treat. I suspect the "rubbery" lens was to enable the tech to just pust out the blown bulb. Which means he could just service it with a pocket full of bulbs!
the word you were looking for was a baffle. "a device used to restrain the flow of a fluid, gas, or loose material or to prevent the spreading of sound or light in a particular direction"
Another indicator that we've used in control rooms a lot. One thing though, when you go to put the bulb carrier back in, there's a notch in the base on one side, that has to line up with the little metal 'tang' folded inside the casing. This prevents you from inserting the carrier upside down. And the other thing is you can quarter turn the front piece the wrong way, making the printing on the front upside down. But if you do this, it becomes a lot harder to pull it back out because of the fit. We had operators sometimes 'help' us out by changing the bulbs themselves. But they wouldn't know the little details and sometimes screwed them up, making it harder for us to take them out again. :/ Another great video.
On the switches I own, the bulb carrier has hinges at the bottom preventing it from being removed from the switch. Makes sense though. You don't want someone to swap carriers (and the ledgends with them) with a neighboring switch, leading to a "wrong" button press. Pressing a Start instead of Stop on a big piece of equipment would be bad if you wanted the opposite.
Other than bulbs (327), I don't recall replacing parts of the switch. Remember replacing the entire switch assembly. Depending on the switch, a rather laborious job at times. The harness' were exquisitely hand wired. KSC Test Conductor Units were huge by today's standards and loaded with those switches. Eventually Shuttle brought in new comm systems and eventually all Apollo era (and before) equipment was replaced. I do remember the last units replaced may have been the audio 4-Wire comm panels.
WoW. If ever something deserved a "They dont make em like they used too" thrown at it!
This is a MSC (Master Specialties Corp) Series 10 "Twist Light". Can be an indicator or a act as a push button switch as well. The face can be split from 1 to 4 individual segments. Can attach a switch block for 2 to 4 switches, maintained or momentary. Very common in G.E. nuclear plant control rooms. Still available new.
As an instrumentation engineer in the 1970s, I used to specify those switches. Used them for a control panel at the IBM Poughkeepsie physical plant. Also spec'd them for use in jet engine test cells/hush houses at Naval Air Rework Facilities and Top Gun near El Toro. They were more expensive than competitive switches by (say) Square D. But they were also more customizable.
I salvaged a bunch of those, long long ago. The rear snaps off to allow for no switches at all (indicator only), momentary or alternate-action switches, from 1 to 4 SPDT micro-switches. Like all military/avionic displays, the lamps are front-replaceable and there are 2 lamps for redundency/safety. There's no built in lamp-test (some are push-to-test). Little silicone hats color the flange-base bulbs.
Yea, that switch module was 4PDT, and Push-On, Push-Off, you could get a diff module that was just momentary... Close on Push, Open when released... I always love the 'positive click' during actuation.... very satisfying ....
When a switch MUST work!!!
The same switches were used in the 1980's on offensive avionic panels in B-1B and updated B-52 bombers. I tested the panels at Boeing before they went into the aircraft. Always enjoyed pushing the "LAUNCH" button.
Thanks for showing this to us, I had no idea. The awesomeness of the Apollo program is palpable even in this lowly ground control switch! And now I know I NEED one...
Hey Marc! Just one? Build a whole control panel with these :-)
I'm surprised you don't have any. They are on ebay, but look out for the scalpers charging >$50 per switch.
@@mrnmrn1 I wish, but these beautiful switches are way expensive! Looking how involved they are, they probably also were quite expensive at the time too!
@@CuriousMarc After some digging around, I found a catalog to try and make some sense out of the cryptic (but necessary) part-number scheme. Pretty amazing product! flamecorp.com/PDF/Safran-Electronics-Defense/10E-H%20Series.pdf
Back in the 70s I worked on control panels using these type of switches. They were difficult to fix when broken. This usually happened when the switch was worn from many cycles.
Nice memories.
They were cheep back then just r andr it and it's fixed
At work we had a big box of similar modular switch assemblies that were salvaged from some old vacuum gear, that we used in all sorts of internal prototypes and lash-ups. We never bothered to remove the old decals so the buttons and lamps never said what they actually did. Our favourites were the buttons that were simply labelled "Baffle".
Whatever else they did they certainly did baffle!
I wonder if a reason for two bulbs per side is redundancy, making it immediately obvious if it's a dead bulb or other fault
It is. That's also common practice in aircraft switches, as well as a lamp test before powering up the aircraft.
I've seen the second bulb in the indicator division used as a backlight for low-light applications. The backlight was often dimmable for the entire switch panel and was a different color than the "active" colors.
Pretty standard in industrial control to have redundant lamps for high priority indications. Not so common to have provisions for redundant power sources.
@@NiHaoMike64 The other "fault" was that both pilots was distracted with trying to get the bulb out to check it. There was no one flying the plane. Very tragic, even a sequence of events brought down the plane. If any had not occurred, the plane would have landed intact and at its destination.
@@NiHaoMike64 Except EAL401 happened in late 1972 after the Apollo system was designed?
My company used tons of those "back in the day" and they were VERY expensive. And since we were not not smart enough to run the bulbs at a slightly reduced voltage, they ate bulbs at a high rate. Bulbs were expensive and Master Specialties never made it easy to remove the lenses. It's jewelery and costs like jewelery.
Do you have any idea about the price range?
@@daggelNot any more, last time I bought them was 15? years ago. Bought/ordered from Grainger and about $1.30 to $1.50 EACH. Who knows now??
It's the tiniest thing but I have to appreciate that this seems to easily be maintainable while it's not only installed but also powered. The common making contact before anything else is the main thing that suggests as much to me, one of those "someone really cared" sort of details.
I love switches. It sounds silly when I say it out loud but it's true.
Having seen these in use, what they did for dead bulb detection was use a ?47 ohm 2W resistor to feed the lamp in the "off" condition, so that it would have a slight glow.
No glow = lamp open
Also, it make the bulbs last longer by keeping the filament warm. Cold filament inrush current is what kills incandescent when they turn on.
I believe there is a little C-frame type tool for popping the head out for bulb-swap sorta like a chip extractor, but more robust and with springsteel ends.
.
Marvelous stuff Fran! My studio at the Beeb had a similar switch, though from a different manufacturer. Being modular you could have the same front end indicator with different switches, so some were not latching, and you could also make them change over. The ones we had didn't have that clever rotating action. We had a special pair of tongs to get the bulb assembly out. The front slid off, then you could get the tongs down the sides to unlatch the assembly and pull it out. The bulbs had the same coloured caps, and the legend was on a piece of transparent celluloid, done with Letraset. The bulbs were 27V but run at 24V, and we even had special tongs for pulling them out! The great thing about them being modular was you could make pretty much any sort of switch you wanted. Their main use in the studio was to operate the internal video routing. The push buttons worked a big relay matrix, which in turn operated video and audio switching. It could be a nightmare to troubleshoot. The latching mechanisms were so clever. Those rollers could be different shapes so you could have 1 or 2 micro switches NO and the other NC. And since they were operating realays in the racks in another room, the lights were switched separately. Lots of long runs of multi core wiring.
I owe you an apology in that when I saw a during of 20 minutes I thought that is pretty long for just an illuminated switch, but in fact I found the entire video riveting. Thanks for posting it.
I was quite impressed that Fran just happened to have the bulbs lying around. :-)
It's slowly getting harder and harder to find incandescent lights these days lol
The whole thing smells of being scripted! Probably by Ron Howard! 🤪
An engineer's spare-parts "junk box" is always filled with precious relics. All sorts of mysterious and unbelievable, clever and curious, useful or useless things. It takes a lifetime to collect these lost arts since none of them ever appear especially interesting or valuable until they just don't make them anymore.
That's the switch that got us to the Moon. Nice.
This is a blast from the past for me. In the early 80s I was working in the UK at a USAF satellite communications station at RAF Croughton and the AN/FSC-78 master control panel used those switches for status and control of the transmitters and some ancillary functions. The control panel interfaced to the station hardware through a control box (3'x3'x4' lwh) that was 54 series TTL.
Likewise, at RAF Fylingdales in north Yorkshire we used these by the by the bucket load. I still have a few as souvenirs when our section was decommissioned. They never went wrong. The bulbs were all 28 volt 40ma under run on 24v.
I always liked those switches. They were quite common on 70s era broadcasting gear.
I share your interest in illuminated indicators. I was a military avionics tech in the late 1960s, aircraft cockpits tend to be full of these types of indicators.
_"I'm going to have to hook this up"_ If anyone wasn't expecting this then shame on you 😁
I was expecting her to connect it so the lights would change
by pressing the switch.
I’m surprised you didn’t have the switches hooked up to toggle the lamps with each push (and some litho inserts) to say [green] FRAN [red] LAB, FRAN, LAB, FRAN, LAB…
Fran, you are AMAZING!! I just discovered your channel and you have already blown our minds with your incredible videos about the Apollo launch vehicle ejectable film canisters, the F1 engine design, and the brain-bending design of the Mission Control video displays, and right now we are watching your exploration of the Mission Control panel switches. You have made my day!! What a terrific communicator you are!!? Your extraordinary knowledge and enthusiasm are as infectious as they are impressive. Congratulations!!! My wife works in science education here in Australia and she is definitely recommending your channel to her colleagues at her school. Hats off! You are my new favourite RUclips channel and I'm already getting RSI from sharing your videos to my friends! Love your work, and so excited to explore all your wonderful videos. Live long and prosper!
silicone colored bulb caps are very common in car instrument clusters before led's were widely used. My car is full of them.
That was common before they decided to cheap-out and just coat the bulb with translucent paint.
Those Molded Rubber "Thingies" are to correct the warm glow of Tungston (the green ones) to a Whiter rendition, and (Yellow) to Amber IIRC
Aah I see the Green ones are greener than I thought, Guess I'm remembering a Blue cap to make Bright White
Agreed, top/bottom split illuminated switches in COLORS are kewl! Move the color caps and use one lamp at a time for either color top independent of either color bottom!
While serving in the US Navy as an Electronics Tech we had crude automated test suites for a sophisticated air search radar set. It used 8 track tapes to load test programs and the control panel had several of these types of switches. They always had a positive feel to them when used and having a light inside confirmed your selection when using the switch.
I love how mechanically over engineered everything from the slide rule era is!!! I bet that thing would last 100 million cycles. (Edit, I am being hyperbolic with the 9 figure cycle count, but I would bet that thing outlasted any system it was used in)
Yeh great hey...ive experienced the evolution of electro mech devices etc over past 35 years...and yes its all made like shit now....” engineering”!
I built a tester for that :)
It was actually used 14 times!
I think that plastic rotating thing wouldn’t last very long
@@radimkolar2270 I did think about that right after I wrote this. I was being a little hyperbolic with the 100 million, but I bet they mechanically outlasted anything they were ever put in. The late 1950s and 1960s brought us some great advancements in plastics with impressive mechanical properties. I imagine that ratchet is some flavor of HDPE possibly impregnated with a lubricant to help with the sliding wear.
I have a reasonable eye for this stuff. For 20 years my job has been mechanical strength analysis simulation and testing. I ensure parts are strong enough to live through their expected life. We use a 2x factor of safety when back then, without the insane computer simulation we have today, they were more like 5-10.
I saw this 2 years ago and just had to come back here. I used a number of these switches in the mid-70's in my electronic hobbyist craze. I used them to make an illuminated control center for my stereo system and speaker switches with relays. I got these at electronic surplus places in Minneapolis, one was Honeywell Surplus. This vid brought back a lot of memories
I remember watching Apollo missions on TV when I was a kid. I was in the second grade when the first one made it into space. It is amazing what they accomplished with technology that probably wouldn't even have enough computing power to play an iTune.
Neat how the plastic rotor in there could be notched out to make it into a customizable sequential switch.
Look for one with the label "DESTRUCT"
That would be pure gold.
The one with label "SIMULATION" would be nice too..lol
Two part switch ought to have LAUNCH and ABORT
How about a switch labeled "ENGINE START" that launched many a Delta rocket through the '70s and into the '90s. I have the actual switch that did that.
When I was in high school, we had TONS of these in our electronics and robotics classrooms, all new in box. They were most likely donated from Rockwell, Allied Signal, or Bendix in the 80s...
I helped take most of them to dumpsters when the school was remodeled in 1996. We had no idea just how special they were!
I'm gonna need 104 of these
I used to build panels up at Sikorsky' Aircraft in the test center and used different bulbs depending on the voltages used. We used similar Unimax switches and when you pulled out the plastic front button you can slide out the plastic panel out to the side. What I would do is in grave the back side of front plastic and fill the engraved area with a black grease pencil or lacquer stick then polish the surface clean. So when the lamp lights you can read what the switch said. Aircraft uses the same type of switches depending on the age and type of plane. I used to work on Jets in the Navy so we would be replacing bulbs often. having 4 bulbs would be for redundancy so if a bulb was out the other would still show the status of the switch or it could actually indicate 4 types of status colors depending on the rubber boot. They also make LED lamps that fit in thoes lamp holders. Those switches are cool to build things with. The hard part was, the square hole was hand filed to fit the switches just right. Have fun with them.
I've worked with a lot of milspec and aerospace kit. They're all beautifully engineered like this :)
When usa and engineering systems had pride and quality
From at least the ‘60s, this type of control was used on many military panels, especially in dedicated “positions,” vs. stand-alone gear where the sky-high cost was prohibitive. For example the AN/FLR-9 “elephant cage” antenna system used them to allow operators to select a beam direction from among several assigned for a given mission. Snazzy indeed!
Still today those who build their own panels would like the same degree of snazziness, but for practically no cost, and it now can be done. Start with the same size tile, drill some holes in it for pockets to hold LEDs, glue it to a rear tile slightly larger vertically (but not horizontally to allow ganging), cut the panel hole to allow the front tile to penetrate, and screw the rear tile to the rear of the panel. For the switch, bring some narrow metal (bare wires?) to the front for touch pickup; the 60Hz buzz picked up can be used to activate a 1-bit logic switch for as long as the contact is touched. Alternatively, pick up skin resistance. From that one switch you can of course feed any desired digital circuits, including debounce, finger pressure, or whatever to achieve the look and feel of the original article. You could even use the pickups to feed a microcontroller to scan an array of tiles saving building the circuitry for each switch. Now everyone can have switch snazziness without all that original mechanical stuff.
Another reason these switches were mainly limited to panels is that they were so hard to push that any small equipment would just slide off the shelf and fall on the floor!
Nicely done. Thanks for taking the time to share the joy of this gem.
There aren't enough beautiful tactile or mechanical switches left in the world.
I'm actually in the process of having to design a new bezel from spun up acrylic unfortunately as no light pipe makers do anything even remotely nice over about 5mm these days.
Our first Mass Airflow machines had switches like that and also the BCD thumbwheel "digiswitches" for entering numeric info.
They make a tool to pop the lens out for bulb changes. Aviation still uses similar switches, for many different uses, but the flashing warning light is the most prevalent. I have run across older aircraft that still uses switches very similar to the one in the video. As time went on the switch mechanisms got more integrated, and then smaller. Newer aircraft are moving to different methods, especially those built in the past decade, but due to the way regulations work, older parts are still used even to replace faulty switches, rather than just install a newer style.
Awsome
In the early 70s I worked in the center that controlled electric power transmission throughout NorCal . These indicators were set up so they glowed white in normal condition and flashed red in off-normal condition.
Two lamps for each condition. The off-normal lamps were energized through an interrupter to provide flashing.
AND, the off-normal lamps had little red booties on them for coloring the light.
Love your work, Fran. Much of the technical stuff flies over my head at the speed of light, but still I find it all fascinating! Your enthusiasm is extremely contagious, thanks!
These switches were also used in power plants built in the ‘70s. They were used in early multiplex equipment. Useful for operating remotely located equipment. Ours was replaced after 30 years when the spare parts were hard to find in the primary market.
7:00 as soon as you said those color filters were flexible rubber, I thought of the semaphore I had for my Lionel train layout back in 1965. The semaphore blade uses red and green lenses made of that same flexible transluscent rubber.
Thanks. Glen
Thanks for this trip down memory lane. I haven't seen these since the mid 1980's when we used a lot of them at a big DOD contractor. They were really expensive, but Mil-Spec, so I've never really seen them outside of DOD stuff. The nicest part was we could just stock all of the individual pieces and easily configure them on the spot. In production the graphics were outsourced, but in the R&D labs we could pretty easily print our own or use rub-on letters.
Wow. I once worked for the company that made that! (about 15 years later)
Used lots of these in the Navy, for Gun and Missile Fire Comtrol Systems. Back in the day, late '60s early
'70s, a lot of the consoles had these types of switches or were very similar. when you had to 'man' a console the first thing you did was hit the lamp test switch, to ensure all bulbs were working. There was a master dimmer control for all the bulbs, 90% of the second bulbs were redundant, however, in some cases, the second bulb had a colored lens in front of it. to show the status of the switch's function. ie. white or red. the faceplates of the switches were engraved or had a silk-screened panel behind them. this showed the switch's function. I seem to remember the bulbs were #327s and hard to replace once the mechanics were removed we found a solution to actually removing the bulb, the Machinist Mates or Gunners Mates had an incredible substance called "Monkey S**T, put on the end of a pencil and it would adhere to anything. Big glob for pulling the bulb out, a small glob for inserting the new bulb.
I remember those switches, they were made by a number of companies and they were a pain. The lamps came in several voltages 6,12,24 and others, and the lamp covers came in a number of colors and there were various messages that went under the bezel, power, overtemp, etc. The switches came in a wide variety of combinations and some were just indicators. Oh I worked on multichannel, single channel, HF, VHF, UHF, Microwave, systems Radar, Krypto, military and after I retired civilian, it was amazing how popular and expensive those switches and indicators used to be.
Awesome video again Fran. Please don't switch subject.
Wow - talk about designing for maintainability... What a little work of art. It doesn't matter how deeply you dig into the 60's space programs, there's brilliant engineering everywhere. Great find and great video!
I love my NASA era hardware collection. We are just a few miles from Mission Control and I have a great collection of those type switches/indicators. The configurations were endless.
@ 14:50 "that's the wrong bulb" LoL - laughing with you, not at you. I've learned over time to check twice and replace once. You live longer that way. Good video.
Great Video! In the 1950's-60s SoCal was a manufacturing and technology center.
Wow Fran! I worked at Nasa from 1976 thur 1990 and made the artwork for the 10x20 as well as the VEOs and DRKs
Built like a tank. That's switch is a classic!
Things were probably sealed a bit due to coffee & cigarettes constantly nearby.
You could hook it up to switch on your garbage disposal... just a thought.
That's quite a switch. I wonder how label inserts would work, I suppose you could laser print something on transparency film and insert it. I recently went searching for some lighted rectangular switches-- not based on NASA consoles, because I can't say I knew much about them. But I worked with early computers and similar sort of rectangular buttons were common on computer equipment, such as IBM tape drives & the like. Labels like, Run, Stop, Reset, Load, etc.. thinking I might want to create a retro looking panel for some project. Found that you can find modern versions of these sorts of rectangular switches on eBay in various colors, in both momentary and latching, and can put your own insert in for the labeling. Nothing as nice as the one you show here though, no doubt making a switch like that today would be prohibitive.
I have seen a similar switch in a piece of equipment i tore down (it was a "Spectrascope 8000" made by LABEN, in Italy in the '70s). It was manufactured by Micro (Freeport, Ill, USA on the label) and it has a very similar, if not identical, construction to the one in the video! Same 4 (with the coloured rubber bulb cover) incandescent bulbs and switch mechanism. It was used as the main power switch in that instrument.
Thanks for showing these Apollo Era pieces of equipment, fascinating stuff was made back in those days!
I built a lot of those consoles back in the day, with a lot of those lighted switches. Because they were actual incandescent bulbs, they used to raise hell with power on current surges.
My ship picked up Apollo 10 on May 26,1969 LPH -5. COOL video 👍👍👍
These switches are 2 parts. The top lamp is the “command”. The lower is a “report”. So you had confirmation from eg from a downlink. We had tons of these in our equipment. They ran 28V bulbs x 4. We can do lamptest on a button. Usually driven by ULN2003s. Neat find 👍🏻
That.... was awesome. Really cool engineering indeed! Loved it.
This type of switch is exactly the same, it is identical to the ones used in the planes of the 60s, 80s, and 90s of the last century. If I remember correctly the manufacturer was KORRY and by the way it was proof of all kinds of misuse and abuse, they were very resistant mechanically speaking. When they failed, they were due to a burned-out lamp or a defective microswitch, in which case the entire set of switches had to be replaced but not the actuator module or the push button. To replace a burnt bulb the task was so simple that the flight crew was able to perform it easily. Nice piece of equipment. The p/n of the bulb was 328 miniature lamp of 28 volts.
It's gloomy outside this morning and this video is great. Anything from Apollo era mission control is worthy of breaking down. The small yet significant displays or buttons show the amazing and creative engineering. Pioneers.
Beautiful piece of design and engineering.
I love these old gadgets.... they are so much more hands on
"Gardena, Calif."
That's old. They weren't even using the modern contraction for California "CA".
There were quite a few contractors that built such things in that area at one time-- TRW in Redondo Beach, some stuff in El Segundo, Inglewood, etc., all not far from Gardena. Fairchild was over there somewhere too at one point.
Those colours are so neat.
Very interesting. Beautifully made switches. Now to find more on mission control.
Yes they are great PBI's. I have many of them, no doubt enough to make a complete Keyset Comm module. Very ingenious Push Button indicators. Very versatile. Great video!
Very cool! Great switch and indicator engineering! Find me a switch today with this much functionality and built for ease of maintenance and longevity.
Just like pre 80's military jets you could actually repair parts.
Wow! Thank you, Fran! I am aircraft engineer (Tashkent, Uzb.). Never deal with mission control equipment - techniclly know, practiclly never touch. You are so cool!
This as commonly known as a PBI (Push Button Indicator). Before I retired, I was a Command and Control SW Engineer in the MCC at Johnson Space Center in Houston. Part of our task was to replace PBIs with touchscreen widgets using xMotif and C/C++. It was a fun project but somehow not as satisfying as the click of a working PBI.
Away the 60s. MSC will be over 55 yrs old and wood have loved to go-to surplus sales in the 70s
I bet they had an equally elegant puller tool for removing the bulb assembly.
So cool seeing Apollo related items.
These are the same exact switches we use on the console of subway cars, worked on them a lot.
I had no idea that these were special. My dad used to buy them at state surplus by the boxful. He even used them all over the dashboard of a kitcar he built in the early 70s. I now have his boxes of them, LOL. He taught me how to open and service them, change bulbs, etc. Some are momentary, some latch. I love that you got one of them (if I had only known you were looking) :)
The transmitter and receiver at the satellite communications school I attended (in 1980) while in the Navy had a lot of these buttons.
Yay! My very first real engineering job in the 80's, I worked on annunciators for major aerospace project at megacorp. Long list of requirements had to be met. Brightness, temperature, force, feel, etc.
CM344 is a 10V lamp, probably chosen for its 50,000 hour life rating. See stevenengineering.com/Tech_Support/PDFs/27INCD.pdf. Chicago Miniature Lamp has been around for decades. Amazing that they still make incandescents.
I went down a rabbit hole with those switches. The Twist-Lite series 10 switch is still available. Master Specialties moved to Costa Mesa and was acquired by Eaton, becoming Eaton Aerospace Controls Division, and more recently by Safran. Flame Enterprises at flamecorp.com has been a distributor since the MSC days and has a great collection of catalogs showing all the options.
A great find. I was looking for the same rabbit hole, but you beat me to it. Beautiful stuff.
That's soooooo freaking awesome!!!! Thank you for your content!!!!
Wow! That is a serious switch. Lovely!
Picked up some of these a few years ago. 70s vintage :)
Came complete with #327 lamps (funnily enough, the same type as suggested in the LT1037 datasheet, for constructing a Wien Bridge Oscillator!)
I belive the mechanism for accessing the lamps is deigned so that they can be changed without accidently pushing the switch.
There is somthing very satisfying about high-quality illuminated switch goodness :D
These are quite commonly used in the petrochemical industry and in power plants, at least they used to be. As far as replacing the lamps, always test the lamps, not just by their ohmic value but actually pass voltage through them (usually 28 volts) to avoid frustration.
In the words of Gene Cranz "Tell me this isn't a government operation ?" "Yep, the illuminated switches are supplied without illumination bulbs."
Stoked up for you Fran. I'm utterly jealous. :)
I'm guessing the reason the bulbs weren't supplied is so they wouldn't have to have separate part numbers for different voltage bulbs. By letting the customer supply their own, they customer chooses the voltage/brightness/bulb life.
If anybody is curious about what happened to that company from what I can find apparently went something like this Master Specialties Co. > Around May 1985 they were absorbed into Eaton and became Eaton Master Specialties Co producing cockpit buttons and what not >2014 Safran acquired Eatons Aerospace division. So its now owned by the French.
Fran, there was a great surplus electronics store in Philly I used to go to in the early 1980s. Fertiks, on Ella St in the NE section. Hours were Thursday evening and Saturday. I think it's long gone now but they had a lots of switches like that and a huge selection of transformers, in quantity in many cases. The claim was you go in there and specify the secondary volts and amps you need and he had a transformer that would fit the bill. In addition to the old Philco plant at C & Tioga, the RCA commercial electronics and broadcast products factory was right over in Camden. I'm sure most of the great surplus came from those factories. There was also H&R which I think downsized and moved to NJ, but Fertik's was much better IMO.
What a treat. I suspect the "rubbery" lens was to enable the tech to just pust out the blown bulb. Which means he could just service it with a pocket full of bulbs!
the word you were looking for was a baffle. "a device used to restrain the flow of a fluid, gas, or loose material or to prevent the spreading of sound or light in a particular direction"
Thank you, Fran, for your videos :)
Another indicator that we've used in control rooms a lot. One thing though, when you go to put the bulb carrier back in, there's a notch in the base on one side, that has to line up with the little metal 'tang' folded inside the casing. This prevents you from inserting the carrier upside down. And the other thing is you can quarter turn the front piece the wrong way, making the printing on the front upside down. But if you do this, it becomes a lot harder to pull it back out because of the fit.
We had operators sometimes 'help' us out by changing the bulbs themselves. But they wouldn't know the little details and sometimes screwed them up, making it harder for us to take them out again. :/
Another great video.
On the switches I own, the bulb carrier has hinges at the bottom preventing it from being removed from the switch. Makes sense though. You don't want someone to swap carriers (and the ledgends with them) with a neighboring switch, leading to a "wrong" button press. Pressing a Start instead of Stop on a big piece of equipment would be bad if you wanted the opposite.
Nice video, I seem to recall the ones in the ATC tower simulator consoles on Keesler AFB taking 327 lamps. Crazy the stuff we remember.
What a find! You couldn't get those bulbs in quick enough. Classic excitement.
Mid-Century Modern design! (My father was an architect from that era so I know the "feel" when I see it. :) So cool.