Show your favorite and most used benchtop PSU

[BravoV]

While doing minor cleaning & housekeeping on my bench table, when I was arranging things & moving stuffs around, was a bit struggled when I lifted my favorite and mostly used bench psu which it's weight about 14 Kg / 31 lbs , then suddenly remembered that this forum has no bench psu thread like the popular one "Show your Multimeter!" thread, took snapshots and here we are.

If you have more than one or too many like Dave does , just post one or two that you "mostly used" when you're tinkering with electronic projects/circuits. Presumably its is adjustable type, and diy type is also welcome. 

Please, post & share the photo of yours, and your own comment about it as well.


Let me start mine,  a 36 volt 10 Amps Japanese linear bench psu Kenwood PD36-10AD (Link), probably made around late 80s or early 90s.

Like :
- The auto emergency shutdown feature (crowbar ?), if the voltage rail crossed the adjustable OVP limit, the power switch will snap mechanically to off position instantly. 
- Very low over shoot in CC mode when turning ON the output, it won't toast a led like the example attached photo below, really love this particular feature. Remember, this is a 10 Amps capable beast.

Dislike :
- Its so damn heavy and did I say its expensive ?    ... looking at the back of my shoulder just in case wifey is peeking 
- Although its working perfectly fine, but still feeling uncomfortable cause there is no service manual available like those cool & great HP (Agilent) bench PSU series. 


Front & rear shots, the rear has all those terminals for many features like parallel/series connection, remote sensing, external reference (volt or resistance) for voltage and current loop, remote output on/off and etc.


Now, your turn.

.

PS : Please, resize the photo like 1024 or max 1280 pixels wide, not the raw huuuge sized photo directly from your camera. Also its highly recommended to use the attachment feature to embed photo in your own post like I did here, rather than using external hosting, why ? A nasty example on the 1st post, image at external hosting simply sucks -> HERE
The attach picture feature is right below the dialog box where you type your post.

[grenert]

I have some bigger and better power supplies, but I use a tiny little folding table as a "bench," so this is the one that sits there most of the time.  It is an HP 6236B triple output supply.  It is + and - 0-20V tracking (goes up to +/-25 V, but not spec'ed at 25 V), with an isolated 0-6V.  I replaced the little knobs that it originally had with some larger ones to make fine adjustments easier.  It has what HP called "current limiting," but if you look in the schematic, you can see that that limit is actually adjustable to some extent by internal potentiometers I've highlighted.  I removed the original trim pots and brought the PCB connections up to locking Clarostat trim pots I've mounted on the top panel.  It allows adjustment from 0-750 mA on the 20V channels.  The supply is spec'ed to 500 mA on those channels, but it is fine for at least a little while with higher currents.  Practically everything I use it for is low current, so most of the time I actually have it turned down to about 200 mA.

EDIT December 21, 2012:
Added another picture with my latest mod.  I inserted a couple of thin PCBs with white SMDs over the meters to provide an illuminated display.  They are powered by the +7.5 V and -12.4 V reference supplies, giving about 20V for the LEDs.  They draw only 20 mA, so no effect on the performance of the supply.

I also have an Elenco XP-720K that has a special spot because I built it myself (and modified it with 10-turn pots and a relay to turn outputs on and off), but no pictures here because I don't want to hear the litany of complaints that you can't build a bench supply with the LM317!

[raymohi]

My Korad KA3005D. It suits my needs.

[leniwiec]

Not my best but most sentimental one. Early 80` DIY psu, 0-80V 600mA. No abs/pcv at those days, knobs/meters and front was made from ebonite ;-)

[BravoV]

I also have an Elenco XP-720K that has a special spot because I built it myself (and modified it with 10-turn pots and a relay to turn outputs on and off), but no pictures here because I don't want to hear the litany of complaints that you can't build a bench supply with the LM317!

Yeah, there are swarming psu Nazis lurking around here that will bash every adjustable bench psu built from LM317 to death. 
Heck, let alone the LM317, infact when I started my electronic hobby long time ago, I used 7815 and 7915 chips and made them into "adjustable" pos and neg supply and it served me well.


@leniwiec,

Wow, ebonite panel, cool classic diy look and the retro style. 

[T4P]

I use a simple (Actually quite complicated inside) but hardy and certainly quite low-noise as well as decent stability

No remote sensing but ah well i could use the DVM inputs  Not as complicated as the PSUs you big boys have but i am content 

[bullet308]

A vintage HP 6200B, just like the one below. I have a couple of others, but this one gets 95% of the work.

[Thomas]

TTi EL302RT
2x 30V 2A plus a 1.5-5V 2A Aux channel.

What I like:

• 1mA resolution on ampere meters - decent accuracy too.
• Output switches.
• Ampere meters show current limit when output is OFF.
• Logarithmic current limit potentiometers - makes it easy to set small currents.

What I don't like:

• The tail is missing on the '9' character 

So - no real issues 
I don't even mind the Fine and Coarse voltage potentiometers. I just center the Fine, adjust the Coarse for the right ballpark, and fine tune if necessary.

Seems to be good quality, no nasty habits.

[BravoV]

• Logarithmic current limit potentiometers - makes it easy to set small currents.

This is new to me, curious how it works ? Is that like a rotary encoder that increase/decrease the steps according the speed of the rotation ?

What I don't like:
The tail is missing on the '9' character

This reminds me of the old day when using 7447 chip, its a BCD to 7 segment decoder, had to hack some connection to make it displays the tail for 9 and 6 font. 

[Shuggsy]

I have some bigger and better power supplies, but I use a tiny little folding table as a "bench," so this is the one that sits there most of the time.  It is an HP 6236B triple output supply.  It is + and - 0-20V tracking (goes up to +/-25 V, but not spec'ed at 25 V), with an isolated 0-6V.  I replaced the little knobs that it originally had with some larger ones to make fine adjustments easier.  It has what HP called "current limiting," but if you look in the schematic, you can see that that limit is actually adjustable to some extent by internal potentiometers I've highlighted.  I removed the original trim pots and brought the PCB connections up to locking Clarostat trim pots I've mounted on the top panel.  It allows adjustment from 0-750 mA on the 20V channels.  The supply is spec'ed to 500 mA on those channels, but it is fine for at least a little while with higher currents.  Practically everything I use it for is low current, so most of the time I actually have it turned down to about 200 mA.

I also have an Elenco XP-720K that has a special spot because I built it myself (and modified it with 10-turn pots and a relay to turn outputs on and off), but no pictures here because I don't want to hear the litany of complaints that you can't build a bench supply with the LM317!

Very cool, and nice mods! I love the new current-limiting pots. If you can keep the back heatsink cool, you should be able to push the currents even more if you need to. Nice

I recently brought a busted 6238B back to life and it's become my go-to PSU for most of my tasks. I also have a MASTECH HY3005D-3 which has two 0-30V@0-5A outputs which can be put in series or parallel by means of the center switches on the front. Nice for the higher-power tasks, but as I said most of my work has been using the 6238B recently.

As a future mod, I'd like to replace the pots in the HY3005D-3 with 10-turn varieties to give me much finer control of the voltage and current-limiting.

[Thomas]

This is new to me, curious how it works ? Is that like a rotary encoder that increase/decrease the steps according the speed of the rotation ?

These are analog potentiometers, not encoders. These are still available with logarithmic track, I think? Probably not as common as the used to, but still.
Anyway, they work really good. I can easily set the current to single digit mA figures up to about 500mA. Of course, I loose the fine resolution at the high end, but that's not a problem.

This reminds me of the old day when using 7447 chip, its a BCD to 7 segment decoder, had to hack some connection to make it displays the tail for 9 and 6 font. 

Yeah, this has an Microchip PIC on each display, so it could (and should!) be corrected in software.

[T4P]

It's a real log pot then, does your pot go up slowly at the first 30 degrees? Because mine does  And then it jumps like a mad jack after that and well at the higher-end it acts like the first 120 degrees which indicates a reverse log pot

[steve30]

Since I don't have anything better at the moment, it'll have to be this one:

[SLJ]

I don't have a favorite but I do use the HP (top) the most. The second one down I use to power digital circuits.  My little Tektronix rack (#3) has a nice clean dual tracking power supply plug-in thats wired in to the Tek DMM through the rack which is convenient.
The old Kerco DC power supply on the bottom is the workhorse when I need lots of current to accidentally blow things up.

[Nirios]

My favorite and only power supply.  HP 6227B

[M0BSW]

This is mine, Watson 0-15v  Amps  at max 35 the volts adjust control has a key at 13.8 ,  used for all my amateur radio electronics, very reliable, and had many offers for it, I orginally used it on  Kenwood 850 DSP.

[slowtwitch]

I probably have about 12 different power supplies laying around, but these two are used the most...

The work horse of the bunch..a Hp 6286..and for the finer things.... a Power Designs TW5005W...

pete

[david77]

I have a few PSU's but this homebrew beast gets 99,9% of the work.
It's a dual 0-32V / 0-5A unit, the circuit is based on Elektor's 1982 design but heavily modified to get it stable under all load conditions.

[cwalex]

I have a few PSU's but this homebrew beast gets 99,9% of the work.
It's a dual 0-32V / 0-5A unit, the circuit is based on Elektor's 1982 design but heavily modified to get it stable under all load conditions.

Looks really nice  I love the green displays. Did you use blank PCB material for the case?

[SeanB]

Looks like blank PCB for sure. Very nice looking unit, love the old C core transformer you used in it. All the advantages of a toroid with the convenience of a bobbin as well.

[david77]

Yup, lightly brushed & varnished copper clad FR4 PCB material is really nice for making cases. I've got a load of the stuff for nearly nix from a board manufacturer some years ago.

[kripton2035]

mine is an hameg 7042 triple power supply - 2 x 32v@2A and 2.7-5.5V@3A
I really like it - bought used from ebay.

[BravoV]

I have a few PSU's but this homebrew beast gets 99,9% of the work.
It's a dual 0-32V / 0-5A unit, the circuit is based on Elektor's 1982 design but heavily modified to get it stable under all load conditions.

David77, the front panel looks great and neat layout you've made there, impressive ! 

About the case design, the technique using big heatsinks on side with pcb inpires me for my next psu build, thank you.

PS : Any chance you could take few snap shots internally and also externally please ? Really curious.

Looks like blank PCB for sure. Very nice looking unit, love the old C core transformer you used in it. All the advantages of a toroid with the convenience of a bobbin as well.

What is so special about this C core transformer ? Its quite rare isn't it ?

[SeanB]

They are very good regulation and power wise, but are difficult to manufacture as they are wound, bound and epoxied then slit in two parts. They have very low noise and no external magnetic fiels worth mentioning, and can be wound on a standard winding machine to give multiple windings with ease.

[torch]

Well my favourite, in terms of precision is this one that I built:



Not as robust as many shown above, I admit. It can only supply about 25 watts. The variable output is controlled by a 20-turn pot and the voltage readout is reasonably close.  For quick use and/or a second leg, there's 12, 5 and 3.3 regulated fixed outputs and a choice of floating or chassis ground. The current reading is total of all outputs and is more of a rough guide than a laboratory standard.

However, the most used is probably this 190 watt baby, 'cause the whole family uses it -- even the grandkids!