I would highly recommend considering one or more of HP's older linear supplies - 62xx series. There are dual models but the singles can be easily wired together to be in parallel, series or series tracking as well. Very low noise, pretty much bulletproof and can be found for a attractive price. A Power Designs model TP340 or TP343 would also be a very good option.
Hal
Hal
Just for reference.
I have two 0-60Vdc (~2A) SMPS power supplies. One also has a 12Vdc and a 5/3.3Vdc pair of supplies inbuilt. Only the 60V sections can have a current limit of 150mA or higher.
They can be referenced so I can make one +/-30V pair for example. Or I can even make one reference the other as +120Vdc. I can natually set the voltage and the current limit.
Are they useful - yes. They are not only a fast way to setup an idea but they can test the big voltage ideas - for example a 230Vdc regulator can be tested with 1V then up to 60V before it’s switched over to higher voltages for tube amps.
If you’re doing solid state you will want w good 32V on each rail with current limiting capabilities for oops moments.
Also you will probably want a pair of 8R 100Watt power resistors (the chassis mount flat ones work well) as a dummy load.
Currently i have them setup for +15V/-15V/+5V for a DAC.
Don’t forget some leads. I use 1000V shrouded but you may find that safety concern limits their use with through bannana plugs etc but I use the same 4mm shrouded connections for my multi meters too for maximum flexibility.
yes a linear supply is probably the best for noise and minimum current capability.
I have two 0-60Vdc (~2A) SMPS power supplies. One also has a 12Vdc and a 5/3.3Vdc pair of supplies inbuilt. Only the 60V sections can have a current limit of 150mA or higher.
They can be referenced so I can make one +/-30V pair for example. Or I can even make one reference the other as +120Vdc. I can natually set the voltage and the current limit.
Are they useful - yes. They are not only a fast way to setup an idea but they can test the big voltage ideas - for example a 230Vdc regulator can be tested with 1V then up to 60V before it’s switched over to higher voltages for tube amps.
If you’re doing solid state you will want w good 32V on each rail with current limiting capabilities for oops moments.
Also you will probably want a pair of 8R 100Watt power resistors (the chassis mount flat ones work well) as a dummy load.
Currently i have them setup for +15V/-15V/+5V for a DAC.
Don’t forget some leads. I use 1000V shrouded but you may find that safety concern limits their use with through bannana plugs etc but I use the same 4mm shrouded connections for my multi meters too for maximum flexibility.
yes a linear supply is probably the best for noise and minimum current capability.
A power supply is very useful for testing most projects.
High-power circuits are the exception.
A power amplifier needs to be brought up in stages: power everything except for the output, then add series resistors to the amplifier's supply to bring up the output, and finally remove the series resistors. I wanted to avoid buying a benchtop power supply that was as big as the amplifier.
Ed
High-power circuits are the exception.
A power amplifier needs to be brought up in stages: power everything except for the output, then add series resistors to the amplifier's supply to bring up the output, and finally remove the series resistors. I wanted to avoid buying a benchtop power supply that was as big as the amplifier.
Ed
ive been using this all day today and the fans have not run yet
Its easy to use once you get to grips with it, i love it
That's good 👍 there is just so much you can build and try out now. The old NE555 timers are great fun to experiment with if you want to try something different. When I was young I wouldn't take anything just on trust, I had to try stuff out. I remember trying to make a class D headphone amp from a 555. TTL logic (7400 series logic) is fun to play with as well.
https://en.wikipedia.org/wiki/555_timer_IC
https://en.wikipedia.org/wiki/555_timer_IC
I just bought an old used hp 6228A, it’s a dual o/p 0-50v at 1A. I like the old look of the analog meters. It works well, meets spec, good price at around $100
Thank you! I’ve got a soft spot for older gear. Plus my town has a lot of history with HP. My father in law was an engineer there. I’ll check these out.
Like this one? I need to do some reading as I don’t know the specs and features off the top of my head, but the price is certainly attractive on this as well as it just being a super cool piece of old gear. https://accusrc.com/product-Agilent...IMBB42wEwYXljjUXRNeZwm1AYqCYRl-hoCymEQAvD_BwE
Weekend is here (and payday!) so I’ll be digging into this in the next couple days. 👊
50 years ago when I was young, I did all my tinkering using a supply I built from a bell transformer, bridge, a couple capacitors, resistors, a pot and 2EF transistors. You can easily build a larger equivalent, and a tracking split supply is not much more. If you are in a position to spend hundreds of dollars on a professional supply, that's fine but it's a bit like buying a college degree. Such become managers and leave the electronics to the "techs".
That's funny, because I was testing out the Samuel Groner low noise pre-amp I built recently, it had a spur in the output, I could not figure it out. Jan suggested scope your grounds, PS etc, well it turns out the college project lab supply was the cause. I open it up, a rats nest 🙂 It has lots of 3 terminal regulators in it, wires running everywhere, a bunch of Motorola crow bar chips, scr's, two humming Hammond transformers put me over the edge.
Well one of the other regs that I was not using was oscillating. All the DC voltages were fine until I through a scope on it 🙂 I can confirm that a lm317t makes a clean oscillator in the low MHz's region 🙂
I said screw it, I ain't going to fix the rats nest and bought a HP6227B and 6228B for total ~ $400 CDN landed, just recently, one arrived and the other is on its way for xmas 🙂 I hope it does not need work. Now I do have good PS designs in pcb form that I could have used and it is a much cheaper alternative.
The 6228B is good for testing everything up to +/-50V at 1A, anything above that for an amp can be unregulated since its usually for the output stage. I got the 6227B as well since at times I need more than two supply voltages. Also the DSO will fit nicely on top of the two supplies 🙂
I looked up the datasheets on those HP supplies, check out the prices, Crap our dollar these days is like 70 cents to the USD too. I think it was about the same in the 80's. No damn way I was going to afford one until, I retire and folks do not know their value anymore, do not care or they are almost at scrap level 🙂
I scoped the 6228B outputs, it's clean and stable, on to testing the SG LN pre-amp again. Those damn electronic lamps spray radiation everywhere.
Interesting I found out that the 6227,6228, use a old RCA CA3025 dual differential amp chip which is the TO-5 can version, the CA3054 is the dip-14 version and also M5109P is a version too. Also that the old HP factory in NJ is now a condo or apartment unit, the internet is wonderful for some 🙂
Well one of the other regs that I was not using was oscillating. All the DC voltages were fine until I through a scope on it 🙂 I can confirm that a lm317t makes a clean oscillator in the low MHz's region 🙂
I said screw it, I ain't going to fix the rats nest and bought a HP6227B and 6228B for total ~ $400 CDN landed, just recently, one arrived and the other is on its way for xmas 🙂 I hope it does not need work. Now I do have good PS designs in pcb form that I could have used and it is a much cheaper alternative.
The 6228B is good for testing everything up to +/-50V at 1A, anything above that for an amp can be unregulated since its usually for the output stage. I got the 6227B as well since at times I need more than two supply voltages. Also the DSO will fit nicely on top of the two supplies 🙂
I looked up the datasheets on those HP supplies, check out the prices, Crap our dollar these days is like 70 cents to the USD too. I think it was about the same in the 80's. No damn way I was going to afford one until, I retire and folks do not know their value anymore, do not care or they are almost at scrap level 🙂
I scoped the 6228B outputs, it's clean and stable, on to testing the SG LN pre-amp again. Those damn electronic lamps spray radiation everywhere.
Interesting I found out that the 6227,6228, use a old RCA CA3025 dual differential amp chip which is the TO-5 can version, the CA3054 is the dip-14 version and also M5109P is a version too. Also that the old HP factory in NJ is now a condo or apartment unit, the internet is wonderful for some 🙂
I guess it was 50 years back, and mine was not that fancy. I had a small battery charger. I added a FWB and two 2,200uFd 25V caps and a screw-strip. An Amp of +/-18V in a handy package. With a few side-parts, that really could cover "all" audio tinkering up to power amps >18W that actually needed their own supply.
Very nice. I’ve been reading this guys stuff. I can’t say whether or not he’s on point, but his snarky attitude makes me laugh! I’m leaning pretty hard towards an HP 6227B if I can find one in good shape. Thanks to member HalFoster for pointing me in that direction.
Hi Hal,
I’ve been looking into these and it seems some of them cover the bases for a good price with many up sides: built like a tank, easy to work on, info abundant, probably very accurate, reliable, and they are just cool. Specifically, I like the HP 6227B. It seems like the best bet for me. According to Mooly (admin) I’ll need at least 1W or two. Some of the 62 series are pushing only .6W or so. I could be reading them wrong. Anyway the 2227B has moved to the front f the line barring someone giving me a strong reason to consider something else. I also work in American manufacturing, so even though it has no barring today given it’s age, I do like buying made in USA.
This is solid advise and yes my focus will be Amps, therefore I will be building a lot of power supplies (I hope). If you have any advise on designs that would be good for a noob (points for explaining what I’m doing and why) I’d be very interested. Thank you.
National Semiconductor's AN-103 for the LM340 regulators has a schematic for a dual-tracking regulator; that's what I used for the power supply I built in BCIT shop class. As shown, it goes from +/-5V to about 15V, but substituting LM317/LM337 should let it start at 1.2V. Current limiting is whenever the regulators give up.
Here's a modern supply with switching pre-regulator:
https://www.analog.com/en/technical-articles/high-performance-portable-dc-bench-power-supply.html
Design files are provided:
https://www.analog.com/en/design-ce...ion-boards-kits/dc2132a.html#eb-documentation
Here's a modern supply with switching pre-regulator:
https://www.analog.com/en/technical-articles/high-performance-portable-dc-bench-power-supply.html
Design files are provided:
https://www.analog.com/en/design-ce...ion-boards-kits/dc2132a.html#eb-documentation