As someone that fixes a lot of test gear from this era you made my skin crawl when you flippantly handled those PCBs, someone out there will want parts off those boards.
But seriously. these units work 100%. and they cost $15. If you want the boards I'm going to throw away (I bought 4 units). I'll ship them to you for $50
Look at ‘diode gone wild’ for handy tips of what to expect from those Chinese 24v psu. Many components are recycled and the transformers have very little copper in them these days. So it would be good to recycle the old PSU as I’d say it would be another good adventure.
That thing was made before China took over all the lower end electronics etc... Must have been some small transformer company in Willets back in the day. Too bad all those jobs got outsourced!
Just a bit off topic, must be way before your employment at HP. They used an oval type connector to mains power. The connectors were made with the load on both The right or the left side depending on how you’re looking at it. Some people say it doesn’t matter with AC voltage. Do you have an opinion on this?
Ah yes, before grounds. Well, the short answer is that it matters and can kill you! In some old tube radios (and other things), one side of the plug is connectected to the chassis ground. So if you are unlucky to have the hot side on the chassis and touch it. zap. ask me how I know. It is very very dangerous. With age those things get even more dangerous with capacitors going bad and stuff. It is the very first thing I change before ever powering up something. and use an isolation transformer to work on that stuff. If you don't know about this issue then please do not work on this stuff. it WILL kill you.
@@IMSAIGuy thanks it’s called a 163?? Neutral Earth Load (17280) Or Load Earth Neutral (17952) Sorry this is what I meant.. Still as Scary? My fault for not being specific enough
short answer is, yes, if you have to ask then yes scarry for you to be working on it. If there is a real ground and it is a three prong to earth ground. then that's better. If there is ambiguity of neutral and hot then it may or may not be an issue. Again, since you are asking, I must say don't touch it until you have more experience working on high voltages.
@@IMSAIGuy again thanks. Found this thread. Love the videos That is called a PH-163 connector. It was popularized by Belden from the mid-1960s well into the 1970s. The style always uses the center pin for ground, but the assignments for neutral and ground were arbitrary! This ambiguity is why the cords fell out of favor and are getting difficult to find today. HP uses what is considered the "reverse" connector wiring. Looking into the end of the cord with the center ground terminal at top, "hot" is on the left and "neutral" is on the right. Up until recently, you could order a replacement cord, Volex part number 17952, from most of the major electronics parts distributors. They no longer seem to be available from those sources, but it may be possible to order them direct from Volex, or from other online distributors that may still have some NOS. Volex bought Belden's power cord and finished cable business some years back, BTW. The "normal" version of a PH-163 cord (which you don't want) is Volex part number 17280. Its "neutral" is on the left, and "hot" is on the right. Like the 17952, this cord is no longer available from major distributors but some dealers may still have it NOS somewhere. If you did get a reversed power cord (perhaps used), it would fit and the instrument would probably work fine, but there would be one little problem. More parts would remain "hot" with the power switch off, increasing the chances of shock when the covers were removed. Also, in some cases there are interference filters built into equipment which might not work effectively if the leads are reversed. For these reasons, the IEC designed the current C13 computer cords with square pins so they cannot get mixed up with PH-163 cords! Some people recommend removing the PH-163 power inlets and replacing them with IEC C14 inlets. Unfortunately this almost always involves drilling new holes and/or cutting the sheet metal. My usual procedure is to simply make a blank plate out of metal that goes in place of the PH-163 inlet with two screws. A hole and grommet in the center accommodate a permanently attached power cord. Should anybody ever want to restore the instrument to its original configuration someday, the mod is very easily reversed.
Good morning IMSAI Guy! I recall the previous videos you made (roughly about a month ago) that included the OPA549 IC - high current/high voltage operational amplifier module. I think you were on a quest to build a +/- 24 volt "buffered, high current/voltage, bench power supply", if I am not mistaken. I distinctly remember that you made two (2) videos, back to back, about this project, but what you didn't reveal (or perhaps you did and I just missed it) was exactly what the use case(s)/application(s) were going to be. So my question remains; what are you planning on using this specialized +/- 24 Vdc power supply for IMSAI Guy? I recall you performing some testing of the circuit with a DC motor, but I am curious about what the final application will be for this design. Will you be using it to control motors on some other device that you haven't gotten to yet? Fred
I'm just getting around to putting it into a box. It is just a piece of generalized bench gear. I don't have a particular project in mind. this high current buffer IS the project.
You can indeed still by LS, F, AC, etc logic from Digikey. The choices become less and less as the months and years go by. I still see sellers on eBay listing these HPIB devices for over $200! I wish I had a junk store like your in my area :( Does your "junk" place have an online presence ?
I have n-o-o problem with you repurposing that gizmo. Maybe remove all the components from the board and reuse it as the bottom? Why make another bottom?
Nice build, interesting story. You probably thought of it but do you think you can pop those supplies out of their box and gain some more room or would that cause a noise problem? Just thinkin out loud. Thanks for the look.
I did consider that. It didn't really buy be much as the PS cases are built in heat sinks and I would have to re-create those, and I would have to make sure to electrically isolate the two. It didn't buy me anything
As someone that fixes a lot of test gear from this era you made my skin crawl when you flippantly handled those PCBs, someone out there will want parts off those boards.
I will do a video me putting them in the rubbish bin.
But seriously. these units work 100%. and they cost $15. If you want the boards I'm going to throw away (I bought 4 units). I'll ship them to you for $50
Great electronics archeology ! My time traveling son said that’s an important graduate course in the future.
I have an up coming video comparing various years this unit was built (I bought more than one).
I remember Weird Stuff and one other surplus electronics stores in the San Jose area back in the 90s. Loved going there
It's the perfect case for the job. Nice one.
I think so too!
Worth it for the case, you could build a nice radio in that...
Look at ‘diode gone wild’ for handy tips of what to expect from those Chinese 24v psu. Many components are recycled and the transformers have very little copper in them these days. So it would be good to recycle the old PSU as I’d say it would be another good adventure.
Unfortunately the old power supplies are linear and I can expect about 500mA current. The switchers will give me 5000mA
If it could swing 3A, a 24V supply would be great to power a TS100 soldering iron.
7824 is only good to 1.5A
That thing was made before China took over all the lower end electronics etc... Must have been some small transformer company in Willets back in the day. Too bad all those jobs got outsourced!
It is still in business!!
@@IMSAIGuy Amazing! Maybe they do small orders? or have some military related contract(s)?
Just a bit off topic, must be way before your employment at HP.
They used an oval type connector to mains power. The connectors were made with the load on both The right or the left side depending on how you’re looking at it. Some people say it doesn’t matter with AC voltage. Do you have an opinion on this?
Ah yes, before grounds. Well, the short answer is that it matters and can kill you! In some old tube radios (and other things), one side of the plug is connectected to the chassis ground. So if you are unlucky to have the hot side on the chassis and touch it. zap. ask me how I know. It is very very dangerous. With age those things get even more dangerous with capacitors going bad and stuff. It is the very first thing I change before ever powering up something. and use an isolation transformer to work on that stuff. If you don't know about this issue then please do not work on this stuff. it WILL kill you.
@@IMSAIGuy thanks it’s called a 163??
Neutral Earth Load (17280)
Or
Load Earth Neutral (17952)
Sorry this is what I meant.. Still as Scary?
My fault for not being specific enough
short answer is, yes, if you have to ask then yes scarry for you to be working on it. If there is a real ground and it is a three prong to earth ground. then that's better. If there is ambiguity of neutral and hot then it may or may not be an issue. Again, since you are asking, I must say don't touch it until you have more experience working on high voltages.
@@IMSAIGuy thanks
@@IMSAIGuy again thanks. Found this thread. Love the videos
That is called a PH-163 connector. It was popularized by Belden from the mid-1960s well into the 1970s. The style always uses the center pin for ground, but the assignments for neutral and ground were arbitrary! This ambiguity is why the cords fell out of favor and are getting difficult to find today.
HP uses what is considered the "reverse" connector wiring. Looking into the end of the cord with the center ground terminal at top, "hot" is on the left and "neutral" is on the right. Up until recently, you could order a replacement cord, Volex part number 17952, from most of the major electronics parts distributors. They no longer seem to be available from those sources, but it may be possible to order them direct from Volex, or from other online distributors that may still have some NOS. Volex bought Belden's power cord and finished cable business some years back, BTW.
The "normal" version of a PH-163 cord (which you don't want) is Volex part number 17280. Its "neutral" is on the left, and "hot" is on the right. Like the 17952, this cord is no longer available from major distributors but some dealers may still have it NOS somewhere.
If you did get a reversed power cord (perhaps used), it would fit and the instrument would probably work fine, but there would be one little problem. More parts would remain "hot" with the power switch off, increasing the chances of shock when the covers were removed. Also, in some cases there are interference filters built into equipment which might not work effectively if the leads are reversed. For these reasons, the IEC designed the current C13 computer cords with square pins so they cannot get mixed up with PH-163 cords!
Some people recommend removing the PH-163 power inlets and replacing them with IEC C14 inlets. Unfortunately this almost always involves drilling new holes and/or cutting the sheet metal. My usual procedure is to simply make a blank plate out of metal that goes in place of the PH-163 inlet with two screws. A hole and grommet in the center accommodate a permanently attached power cord. Should anybody ever want to restore the instrument to its original configuration someday, the mod is very easily reversed.
Good morning IMSAI Guy! I recall the previous videos you made (roughly about a month ago) that included the OPA549 IC - high current/high voltage operational amplifier module. I think you were on a quest to build a +/- 24 volt "buffered, high current/voltage, bench power supply", if I am not mistaken. I distinctly remember that you made two (2) videos, back to back, about this project, but what you didn't reveal (or perhaps you did and I just missed it) was exactly what the use case(s)/application(s) were going to be. So my question remains; what are you planning on using this specialized +/- 24 Vdc power supply for IMSAI Guy? I recall you performing some testing of the circuit with a DC motor, but I am curious about what the final application will be for this design. Will you be using it to control motors on some other device that you haven't gotten to yet? Fred
I'm just getting around to putting it into a box. It is just a piece of generalized bench gear. I don't have a particular project in mind. this high current buffer IS the project.
@@IMSAIGuy Thanks for the response! Ah ha. Okay, makes perfect sense in this light. Fred
You can indeed still by LS, F, AC, etc logic from Digikey. The choices become less and less as the months and years go by. I still see sellers on eBay listing these HPIB devices for over $200! I wish I had a junk store like your in my area :( Does your "junk" place have an online presence ?
www.excesssolutions.com/
@@IMSAIGuy Thank you!
🦦 cool can you talk about these esoteric part in ttl logic 🐬
I have n-o-o problem with you repurposing that gizmo. Maybe remove all the components from the board and reuse it as the bottom? Why make another bottom?
Ah, Miss Willits! LOL
Nice build, interesting story. You probably thought of it but do you think you can pop those supplies out of their box and gain some more room or would that cause a noise problem? Just thinkin out loud. Thanks for the look.
I did consider that. It didn't really buy be much as the PS cases are built in heat sinks and I would have to re-create those, and I would have to make sure to electrically isolate the two. It didn't buy me anything
@@IMSAIGuy understood.