I remember these well. I worked in a TV repair shop in high school, and the horizontal sweep circuit contained a PLL locked to the sync pulses in the video signal. These dual diodes were used as the phase detector.
Not International Rectifier. The company name is International Resistance Co. The Omega / Ohm symbol in the IRC logo gives it away. The plant was in Philadelphia, PA. TT Electronics bought them in 1990 and closed the plant somewhere around 2013-2014. IRC is still around under their parent company TT Electronics and still making resistive products, just not in the USA anymore.
I think that you have a bunch of old cranky retired guys watching your channel. It was either 1960 or 61 I took an electronics class in high school. One thing we did was build a large 12VDC power supply. Even had to fabricate the chassis. The rectifying element was a selenium rectifier. We didn't know at the time that we were risking our lives and others because of the evil selenium. We all survived. The power supply took up residence in the rafters of the garage but I haven't seen it in years. Nice video. Thanks!
I used to replace one of these AFC Detector or Horizonal Phase Detector diodes every so often when I worked in TV shops in 1974 and 1975. The diode was used to detect the horizontal sync pulse out of the video. They would fail open after 5 to 10 years. Some TVs had these in a socket. If my memory serves me correctly, these sold for about $0.25. It would have been much better to use a pair of 1N914s, which would totally eliminate the failure but, with TVs, every cent of part cost was taken into account. Small selenium rectifiers were also used on the convergence board (4 diodes), and in the high voltage, for the focus rectifier, and CRT anode high voltage rectifier (Single, or 6 to 8 diodes used in a voltage tripler or quadrupler).
Vacform package, used to be common, using a thin PVC film with the cardboard having a varnish layer applied. The large board is put on a heater platen with holes for the suction, then the PVC film was put on top, and clamped down, then suction pulled the hot plastic onto the card, and the varnish made the glue bond. Used to be very common, and still used by some small packaging companies.
Two D5 and you have a FULL BRIDGE RECTIFIER! Three of them and you have a 3-phase one. And as many as you need to make a high voltage one... I like that Fnirsi M-tester. The enclosure looks well-designed, durable and practical.
I used to take the rectifiers apart , strip the paint and use them to demonstrate solar electric effect. They will output a voltage when exposed to sunlight. I don't remember how much voltage as this was over 60 years ago back when I was a curious kid.
These show up in Seeburg jukebox amplifiers. They were used in the AVC (automatic volume control) circuit. Those old 45s were all over the place in volume, so the circuit leveled it out so you wouldn't have to constantly adjust the volume up and down.
Not just used in color sets, they were in LOTS of B/W sets, as well. Used in the horizontal phase detector circuit. Color sets often used another selenium multiple diode package in the convergence circuitry.
Yup, dc clamp diodes, in Britain the diode of choice for convergence circuitry was a diode connected germanium transistor, ac128 or similar, these old jobs here were used in flywheel sync circuits in old time valve tv sets.
The telephone company, when customers complained about frequent horrendous cracking sounds, remedied the phones with anti-parallel selenium diodes addition into the ear piece. Worked quite well. I tried my version, two silicon diodes, which also worked, but if I recall, they were too sharp responding, causing some distortion to the voice. As you see on the curve tracer, the leakage appears quite early, but then the slope is less deep than that of silicon diodes.
Those Selenium diode packs were likely old stock from a radio TV repair supply store. I hung out at at a TV repair shop when I was in grade school, circa 1956. My duties were to fetch coffee, sugary snacks, and to listen for the horizontal whistle. The older gentleman who taught me how to fix things could not hear it. Most of the Selenium rectifiers used in those days had several flat plates. Even though they were painted, you could still get a nasty shock if you touched the plates.
The scouring pad is Scotch Brite from the Minnesota Mining and Manufacturing Company, or 3M since 2002. The green ones are for regular use and the red ones are Extra Heavy Duty such as removing burnt on food residue from ovens.
They're not just for dishes - they're widely used in machine shops, auto repair, etc etc. Anywhere you want a non-sandpaper abbrasive. You can even get scotch brite wheels for your bench grinder / buffer, as well as scotch brite discs called "cookie wheels" for your die grinder. The maroon is coarse, green is medium, and grey is fine. Blue is non-abbrasive and is only the nylon pad (good for use on glass or ceramics, or other items you want to scrub but not scratch, such as anything painted)
Phase detector diode for TV horizontal sweep. They compared horizontal pulses from the sync separator and a tap off the flyback transformer; error voltage was applied to horizontal oscillator.
Well, at least the forward voltages are relatively well-matched within the same package...? :) Scotch-Brite pads are one of those ubiquitous things on anyone's bench who works on stuff over...let's say "a few decades" old. I've found they're even better when used with alcohols, (odorless) mineral spirits, or even soapy water, depending upon the application. One of the best things about them is that you can cut them to any size you need, which helps when cleaning items with nooks & crannies, or if you need to roll it up or wrap it around something.
Advanced users use the pads under a random orbital palm sander. With the addition of WD40, it's great for cleaning up cast iron surfaces on tools (like table saws, jointers, drill presses, etc etc), or by hand even to clean up rusty ways on lathes and mills! For cleaning precision surfaces, I would only use green or grey, not maroon - maroon is quite coarse. And the non-abrasive blue scotch brite pads work great on anything painted, or glass or ceramic without scratching it!
From an “old “ fart: Selenium rectifiers are not all that dangerous, unless you grind them up in tiny pieces and sprinkle on your cereal . Even then you probably would just have an upset stomach. That little afc/phase detector diode array would never see enough current thru it to cause it to smoke . Larger Selenium rectifiers (plate area 4 x4” ) used in battery chargers could heat up and burn if heavily overloaded, and give of an oder, but not enough to stink up a whole house or cause you to get sick. Selenium stacks can handle large current surges and if that happens the selenium coating can bubble and have localized blistering, but then recover and keep working. The surge handling capability makes them a better choice over silicon diodes The people who spread misinformation about selenium are the same folks that complain old tektronix scopes produce enough heat to warm their shops. The same folks who do wholesale capacitor replacement because they can’t do component level troubleshooting. I’m sick of these old hen tales.
Selenium rectifiers were the first semiconductor rectifiers for higher blocking voltages. Before their invention tube diode rectifiers have been used. In fact it was unclear what happens inside of the selenium metal transition. Schottky described it as a Schottky barrier. In Germany there is a funny saying for these rectifiers. Rectifier in German means "Gleichrichter". Selenium rectifier have a very characteristic fouly smell during operation due to the emission of selenium compounds. So "Gleichrichter" was pronounced "Gleich riecht er" (Soon it will smell).
I'm guessing 948 as a date code indicates 1959, week 48. I've seen various parts labelled with one year digit and two week digits. I guessed 1959 instead of 1969 just because the packaging was so similar that I thought the closer year would be a better guess, as packaging in products changes fairly commonly.
The D6 is commonly used in tube type artisan guitar pedals in the audio clipping circuit to create a unique sound effect that is different from germanium and silicon. Small selenium rectifiers are getting harder to find and the price is just going up.
Haha I've had one of these sitting in my random parts bin for years and had no idea what it was. Not the easiest things to find information about. One of the diodes is shot but at least now I know what it is!
How about replacing Se rectifier in vtvm PS: Would one need to add a resistor with the Si diode to better replicate the old diodes effect on the circuit behavior?
The smell of one of these selenium rectifiers blowing up during use is so bad if not exiting you out of the room, ...for hours! The odor is almost similar to a rotten skunk like smell in a very odd way!
Scocthbrite....SiC..Marroon.. Best overall..not two aggressive....but coarse enough.... Our scrub monkeys like progressive...purple to grey...using Spin Doctor... Or grey to white..for fine finish IRC made lots of power resistors.. IR...still alive...but a new name......I like their power MOSFET IRF-250...diodes..SCR One fab in El Segundo CA.. I think IR was in Phoenix too.. Readers know... I wonder if the dual diode shown... Can it recifity 1 amp?... We want little transformer...10 VA..24 VAC.center tap... Compare to two 1N4001... Toss active load on filter cap output.... Would the IR smoke at 300 mA... I guess it be nice to see the I foward current rating...and Vr breakdown Since Vf...is like 2.3....vs say close to 0.7 with the IN4001... You know it will run hotter.... Or you will need higher transformer voltage...to cover the drop... But IMASI......already knows that.... He wants to learn something new...very little left... Thanks for showing old goodies from past It's amazing how these dual diodes...are the heart of some PLL... I like to see that circuit... Enjoy...! Thanks for chip of the day!
better or worse than blown up RIFAs? Better or worse than spontaneously self igniting tantalums? Better or worse than reverse polarity electrolytics after they explode? I need some context here!
Dual selenium rectifiers were used in older televisions and other electronic devices as rectifiers to convert alternating current (AC) into direct current (DC). Selenium rectifiers were popular in the mid-20th century before silicon rectifiers became more common. These rectifiers were called "dual" because they contained two separate selenium plates or stacks, each functioning as a half-wave rectifier. When connected properly in a circuit, these two halves would work together to convert both halves of the AC waveform into DC. Selenium rectifiers had several advantages, such as their ability to handle high currents and their reliability. However, they also had drawbacks, including their relatively high cost, inefficiency (compared to silicon rectifiers), and the fact that they could degrade over time, emitting a foul-smelling and toxic gas if they failed. Due to these drawbacks and the advent of more efficient and reliable semiconductor rectifiers, selenium rectifiers are no longer used in modern electronics.
I remember these well. I worked in a TV repair shop in high school, and the horizontal sweep circuit contained a PLL locked to the sync pulses in the video signal. These dual diodes were used as the phase detector.
Thanks, I wondered in which circuit they would be used
Not International Rectifier. The company name is International Resistance Co. The Omega / Ohm symbol in the IRC logo gives it away. The plant was in Philadelphia, PA. TT Electronics bought them in 1990 and closed the plant somewhere around 2013-2014. IRC is still around under their parent company TT Electronics and still making resistive products, just not in the USA anymore.
this comment made it...
I think that you have a bunch of old cranky retired guys watching your channel. It was either 1960 or 61 I took an electronics class in high school. One thing we did was build a large 12VDC power supply. Even had to fabricate the chassis. The rectifying element was a selenium rectifier. We didn't know at the time that we were risking our lives and others because of the evil selenium. We all survived. The power supply took up residence in the rafters of the garage but I haven't seen it in years. Nice video. Thanks!
I'm old and cranky
I took a selenium dietary supplement to help grow hair. It can't be that.dangerous.
I used to replace one of these AFC Detector or Horizonal Phase Detector diodes every so often when I worked in TV shops in 1974 and 1975. The diode was used to detect the horizontal sync pulse out of the video. They would fail open after 5 to 10 years. Some TVs had these in a socket. If my memory serves me correctly, these sold for about $0.25. It would have been much better to use a pair of 1N914s, which would totally eliminate the failure but, with TVs, every cent of part cost was taken into account.
Small selenium rectifiers were also used on the convergence board (4 diodes), and in the high voltage, for the focus rectifier, and CRT anode high voltage rectifier (Single, or 6 to 8 diodes used in a voltage tripler or quadrupler).
Vacform package, used to be common, using a thin PVC film with the cardboard having a varnish layer applied. The large board is put on a heater platen with holes for the suction, then the PVC film was put on top, and clamped down, then suction pulled the hot plastic onto the card, and the varnish made the glue bond. Used to be very common, and still used by some small packaging companies.
Two D5 and you have a FULL BRIDGE RECTIFIER! Three of them and you have a 3-phase one. And as many as you need to make a high voltage one...
I like that Fnirsi M-tester. The enclosure looks well-designed, durable and practical.
I used to take the rectifiers apart , strip the paint and use them to demonstrate solar electric effect. They will output a voltage when exposed to sunlight. I don't remember how much voltage as this was over 60 years ago back when I was a curious kid.
From back in the good old days when most electronics equipment was manufactured in the USA!
These show up in Seeburg jukebox amplifiers. They were used in the AVC (automatic volume control) circuit. Those old 45s were all over the place in volume, so the circuit leveled it out so you wouldn't have to constantly adjust the volume up and down.
Not just used in color sets, they were in LOTS of B/W sets, as well. Used in the horizontal phase detector circuit. Color sets often used another selenium multiple diode package in the convergence circuitry.
Yup, dc clamp diodes, in Britain the diode of choice for convergence circuitry was a diode connected germanium transistor, ac128 or similar, these old jobs here were used in flywheel sync circuits in old time valve tv sets.
The telephone company, when customers complained about frequent horrendous cracking sounds, remedied the phones with anti-parallel selenium diodes addition into the ear piece. Worked quite well. I tried my version, two silicon diodes, which also worked, but if I recall, they were too sharp responding, causing some distortion to the voice. As you see on the curve tracer, the leakage appears quite early, but then the slope is less deep than that of silicon diodes.
Brown ScotchBrite is highly, highly abrasive.
Those Selenium diode packs were likely old stock from a radio TV repair supply store. I hung out at at a TV repair shop when I was in grade school, circa 1956. My duties were to fetch coffee, sugary snacks, and to listen for the horizontal whistle. The older gentleman who taught me how to fix things could not hear it. Most of the Selenium rectifiers used in those days had several flat plates. Even though they were painted, you could still get a nasty shock if you touched the plates.
The scouring pad is Scotch Brite from the Minnesota Mining and Manufacturing Company, or 3M since 2002.
The green ones are for regular use and the red ones are Extra Heavy Duty such as removing burnt on food residue from ovens.
They're not just for dishes - they're widely used in machine shops, auto repair, etc etc. Anywhere you want a non-sandpaper abbrasive. You can even get scotch brite wheels for your bench grinder / buffer, as well as scotch brite discs called "cookie wheels" for your die grinder. The maroon is coarse, green is medium, and grey is fine. Blue is non-abbrasive and is only the nylon pad (good for use on glass or ceramics, or other items you want to scrub but not scratch, such as anything painted)
@@gorak9000 There is a color code for the abrasive level.
Ooof.. I'm old enough to remember the Zenith jingle, too.
Expected reverse voltage curves as well.
Phase detector diode for TV horizontal sweep. They compared horizontal pulses from the sync separator and a tap off the flyback transformer; error voltage was applied to horizontal oscillator.
Super! Thank you very much!
Well, at least the forward voltages are relatively well-matched within the same package...? :)
Scotch-Brite pads are one of those ubiquitous things on anyone's bench who works on stuff over...let's say "a few decades" old. I've found they're even better when used with alcohols, (odorless) mineral spirits, or even soapy water, depending upon the application. One of the best things about them is that you can cut them to any size you need, which helps when cleaning items with nooks & crannies, or if you need to roll it up or wrap it around something.
Advanced users use the pads under a random orbital palm sander. With the addition of WD40, it's great for cleaning up cast iron surfaces on tools (like table saws, jointers, drill presses, etc etc), or by hand even to clean up rusty ways on lathes and mills! For cleaning precision surfaces, I would only use green or grey, not maroon - maroon is quite coarse. And the non-abrasive blue scotch brite pads work great on anything painted, or glass or ceramic without scratching it!
Curve tracer loveliness!
I heard that slogan as "Where the quality goes in when the product comes back". Lol.
You can replace those with schottky dual diodes out of old PC power supplies. Works perfectly.
would have been interesting to see the reverse breakdown region too :-)
From an “old “ fart:
Selenium rectifiers are not all that dangerous, unless you grind them up in tiny pieces and sprinkle on your cereal . Even then you probably would just have an upset stomach. That little afc/phase detector diode array would never see enough current thru it to cause it to smoke .
Larger Selenium rectifiers (plate area 4 x4” ) used in battery chargers could heat up and burn if heavily overloaded, and give of an oder, but not enough to stink up a whole house or cause you to get sick. Selenium stacks can handle large current surges and if that happens the selenium coating can bubble and have localized blistering, but then recover and keep working. The surge handling capability makes them a better choice over silicon diodes
The people who spread misinformation about selenium are the same folks that complain old tektronix scopes produce enough heat to warm their shops. The same folks who do wholesale capacitor replacement because they can’t do component level troubleshooting. I’m sick of these old hen tales.
Selenium rectifiers were the first semiconductor rectifiers for higher blocking voltages. Before their invention tube diode rectifiers have been used. In fact it was unclear what happens inside of the selenium metal transition. Schottky described it as a Schottky barrier.
In Germany there is a funny saying for these rectifiers. Rectifier in German means "Gleichrichter". Selenium rectifier have a very characteristic fouly smell during operation due to the emission of selenium compounds. So "Gleichrichter" was pronounced "Gleich riecht er" (Soon it will smell).
Yep the trusty TC3. I love it and thanks for recommending it.
In Germany we call them "gleich riecht er". ;)
I'm guessing 948 as a date code indicates 1959, week 48. I've seen various parts labelled with one year digit and two week digits. I guessed 1959 instead of 1969 just because the packaging was so similar that I thought the closer year would be a better guess, as packaging in products changes fairly commonly.
The D6 is commonly used in tube type artisan guitar pedals in the audio clipping circuit to create a unique sound effect that is different from germanium and silicon. Small selenium rectifiers are getting harder to find and the price is just going up.
The common cathode version makes more sense to me than the anode-cathode connected version. I'm curious as to how the latter would be used.
Very nice, thanks for the video.
Thanks 👍
Biggest question. Do they smell? Especially warmed up.
Haha I've had one of these sitting in my random parts bin for years and had no idea what it was. Not the easiest things to find information about. One of the diodes is shot but at least now I know what it is!
I miss my ECG catalog!!!
My Dad gave me one back in 1980
What about reverse characteristics?
How about replacing Se rectifier in vtvm PS: Would one need to add a resistor with the Si diode to better replicate the old diodes effect on the circuit behavior?
Seems Selenium Diodes were also used as varicap tuning diodes! Didn't know that before.
It is call bear hair.
I should have kept my dad’s old Zenith, I probably could have gotten it working again with your videos
The smell of one of these selenium rectifiers blowing up during use is so bad if not exiting you out of the room, ...for hours! The odor is almost similar to a rotten skunk like smell in a very odd way!
International Resistor Corporation. I had a IRC color code decoder in the 1960s
How many of these has shango066 replaced recently? 🤔
Reverse breakdown voltage?
20-30V per plate
20-30V на одну пластину
They do have a nice smooth curve.
Scotch-Brite™ :)
reverse????
Scotchbrite by 3M
YES ! ... a burning Selenium rectifier is a REAL stinker ( Ha - Ha ) ......... DAVE™🛑
IQ detector? I remember them but not exactly the purpose,... yes I dated myself.
Scocthbrite....SiC..Marroon..
Best overall..not two aggressive....but coarse enough....
Our scrub monkeys like progressive...purple to grey...using Spin Doctor...
Or grey to white..for fine finish
IRC made lots of power resistors..
IR...still alive...but a new name......I like their power MOSFET IRF-250...diodes..SCR
One fab in El Segundo CA..
I think IR was in Phoenix too..
Readers know...
I wonder if the dual diode shown...
Can it recifity 1 amp?...
We want little transformer...10 VA..24 VAC.center tap...
Compare to two 1N4001...
Toss active load on filter cap output....
Would the IR smoke at 300 mA...
I guess it be nice to see the I foward current rating...and Vr breakdown
Since Vf...is like 2.3....vs say close to 0.7 with the IN4001...
You know it will run hotter....
Or you will need higher transformer voltage...to cover the drop...
But IMASI......already knows that....
He wants to learn something new...very little left...
Thanks for showing old goodies from past
It's amazing how these dual diodes...are the heart of some PLL...
I like to see that circuit...
Enjoy...!
Thanks for chip of the day!
They make YOUR workshop smell GREAT when overloaded ( technician's aromatherapy ? ) ........ DAVE™🛑
better or worse than blown up RIFAs? Better or worse than spontaneously self igniting tantalums? Better or worse than reverse polarity electrolytics after they explode? I need some context here!
ScotchBrite (spelling?)
Scotch Brite is a trade mark spelling. And that’s two words, with a space between.
what dess chatgpt say about them
Dual selenium rectifiers were used in older televisions and other electronic devices as rectifiers to convert alternating current (AC) into direct current (DC). Selenium rectifiers were popular in the mid-20th century before silicon rectifiers became more common.
These rectifiers were called "dual" because they contained two separate selenium plates or stacks, each functioning as a half-wave rectifier. When connected properly in a circuit, these two halves would work together to convert both halves of the AC waveform into DC.
Selenium rectifiers had several advantages, such as their ability to handle high currents and their reliability. However, they also had drawbacks, including their relatively high cost, inefficiency (compared to silicon rectifiers), and the fact that they could degrade over time, emitting a foul-smelling and toxic gas if they failed.
Due to these drawbacks and the advent of more efficient and reliable semiconductor rectifiers, selenium rectifiers are no longer used in modern electronics.
@@IMSAIGuy thanks
The curve tracer is useful to figure out what resistor to use with the Si diode when replacing these Se diodes.
Chip? Not
It is if I say it is! 😎
@@IMSAIGuyoh
Scotchbrite
Scotchbrite