The power supply from Hell, HP Model 6433B
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- Опубликовано: 30 июл 2024
- The Hewlett Packard Model 6433B DC Power Supply from the mid 1960's, will quite happily put your project into orbit before the current limit activates.
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Music “Let It Run” with permission, copyright Cristie/MacFarlane. 
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just scored an HP 6433B apear to be in mint looking condition, your VERY important video helped a lot, thanks mate.
I used to rejuvenate old NiCd batteries in a similar fashion. A little project box, with a salvaged transformer, that gave 100VAC, at around 10mA, that fed a bridge rectifier that charged a used 100uF 250V capacitor. Then a switch that applied this to the battery contacts. Would click, and after 3 or 4 shots your whiskers would be all blown away for a month or so, till they grew back. Used it to rejuvenate cordless phone battery packs, where they would last around a year longer, before i would need to replace the 4 AA cells in the pack with new.
The Triac you are referring to is on the primary side of the transformer. The purpose was to limit the in and out voltage across the series pass transistor. I think it was an ingenious design. Modern linear power supplies use multitap transformers and relays to minimize the voltage difference across the series pass element thus reducing the amount of heat the transistor would have to dissipate.
I just acquired two HP 6448B supplies and I already know they have a good impulse capability before the current control kicks in. In fact the manual also covers it like you show! Linear VS digital. I like the older stuff.
You might have already noticed that if you lower the current knobs to zero, the supply itself will stop producing voltage. You do this before you connect your load and then move the current knob up while confirming you do not have a short. Soft start.
Unusual :)
I got one of those power supplies used as a teenager from a surplus store. It never worked (and I didn't manage to fix it) and I eventually unloaded it as "for parts or repair" at a Hamfest. Now I realize maybe I'm lucky I never figured out what was wrong with it, haha.
Holy smokes, current limiting on the primary side (mains). Better than nothing but not by much.
Yes, smokes indeed.
Wow! To think that I was lusting after one of these jobbies... I never would've guessed I'd be buying a super expensive light dimmer...
Great cautionary tale given here. I bet it applies to other PSU's of that age too..
Always use common sense - never trust equipment blindly.
They have their uses, but the slow response makes them a bit dangerous for some applications.
@@video99couk I'd only buy one of those in order to be able to test-power up old equipment with a likelihood of having old and possibly failing or deteriorating caps inside. The voltage and current limit would provide some element of safety in that a failing/deteriorating cap would not leak more than I would allow it to and thus cause huge damage. I have some such devices which I haven't powered up between 4 to 10 years which were made in the 80s or 70s. Unfortunately the latter are the more expensive ones and the ones I haven't powered up for the longest period. Granted, a current limited PSU would not provide total safety from damage unless it allows limiting the current down to, say, a fraction of a mA. Even a PSU that allows limiting, say, to 100mAs could be of use provided it won't allow a turn on spike. One could of course take measures against that provided they know in advance that the PSU does not trigger the limit instantly. In essence, I'd use such a PSU briefly to check for cap problems and then probably disconnect the offending caps from the circuit and use the PSU current limiting to try to partially reform them. It's a lot of hassle, isn't it? Going through the DUT's caps with the in-cicuit component tester might save some time of course but these component testers only provide a limited output voltage (9Vor 12V I think?) which is mostly or no relevance to the real working voltage and (most importantly) cost almost as much as bench PSU.
I have the same power supply as this i think mainly the reaon there like that is becuse there not much as a lab supply it more to run machines and stuff like that on a dedicated site like bt equipment mabey ?
That's probably part of it, yes. It's probably not primarily a lab supply.
video99.co.uk myne is slighty diffrent model i noticed myn is a 6263b and has adjustable over volt ajustment on the front right side as i noticed your one did bot have that but i see what you mean buy it stores power when you shut it off with no load the caps inside are massive i dont think iv seen any that big in a power supply before lol
Family steps in when the Moans are out.
That's my nod to *Techmoan,* though there's no such reference in this video.
Later videos may have some Techmoan references though.
ANd, your kids never trust what you say again :)
You're clearly underrated... sad to see... grab a sub and like