Good power supply?

[5370H55V]

Hi all, I'm looking to purchase a benchtop power supply for my home lab for under $250 if possible. I've started looking into buying older supplies like the E3630A since it seems like I can get a better supply for my money, but  what are some other options in my price range (both new or used)?
Any issues I should be aware of or look out for when buying older power supplies?

[engrguy42]

What functionality do you need? How much ampules? How many voltages? Will you need multiple outputs? What about getting an old ATX supply and modifying? Constant current? 

Nobody knows what you need, or what your definition of "good" is. Only you.

[nctnico]

IMHO an HP/Agilent 66311B (or similar) could be a good option (after mounting a Noctua fan in it).

[wraper]

IMHO an HP/Agilent 66311B (or similar) could be a good option (after mounting a Noctua fan in it).

IMHO changing 2 resistors in fan control circuit works better based on my experience with 6612C (I replaced fans too). Also if it's made similar, there likely is one internal VREG heatsink which runs very hot (like over 100^oC) if fan speed reduced to make it quiet even though main heatsink still remains cold. So in the end I made it run significantly louder than I would like, though incomparably quieter than originally.

[rvalente]

Supplies I use, like and would recommend (altought do not know their needs)

66332A - 20V 5A
6633A - 50V 2A

62 series

Im sure with those (and many others) you just can't go wrong

[Grandchuck]

Lots of those available on ebay!  Also, it appears that the schematics are available too:
https://www.eevblog.com/forum/testgear/schematic-for-agilent-e3630a/msg348279/#msg348279

It is a bonus to have test gear that can be repaired.

[5370H55V]

What functionality do you need? How much ampules? How many voltages? Will you need multiple outputs? What about getting an old ATX supply and modifying? Constant current? 

Nobody knows what you need, or what your definition of "good" is. Only you.

I'm looking for a linear power supply with a digital display that can provide at least 1A at 24V, with one more 5V or 6V rail. This means a dual output supply is fine if it goes 0-25V, or a triple if it has two 0-20V rails plus a 6V. I have not considered modding an ATX power supply, how do they compare? I thought most of the adjustable voltage conversion kits use a switching regulator to control the output?

[engrguy42]

An ATX typically is a switching supply that has 12v, 5v, and 3.3 v, non adjustable, and with no constant current stuff or digital display unless you add all that. So it sounds like that's off the table for you.

[rvalente]

Agilent E36 series, a bunch of models. Search on ebay

[Gyro]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

[engrguy42]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

 

Wow. The arrogance.

Gimme a break. ATX supplies are perfect fine for tons and tons of users. Geesh.

[tautech]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

 

Wow. The arrogance.

Gimme a break. ATX supplies are perfect fine for tons and tons of users. Geesh.

Nope, wisdom and experience. 

[tautech]

@5370H55V
~$100 more than you wanna spend is SPD3303X-E

[engrguy42]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

 

Wow. The arrogance.

Gimme a break. ATX supplies are perfect fine for tons and tons of users. Geesh.

Nope, wisdom and experience. 

I'm sure. And nothing to do with the fact that you're a Siglent distributor recommending Siglent power supplies...

[tautech]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

 

Wow. The arrogance.

Gimme a break. ATX supplies are perfect fine for tons and tons of users. Geesh.

Nope, wisdom and experience. 

I'm sure. And nothing to do with the fact that you're a Siglent distributor recommending Siglent power supplies...

Nothing at all, I've not recommended anything. Only pointed out a locally available choice for consideration.

Whereas you have recommended a recipe for disaster !

[Gyro]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

 

Wow. The arrogance.

Gimme a break. ATX supplies are perfect fine for tons and tons of users. Geesh.

Not at all, the OP is asking for PSU suggestions for developing circuits. I My advice was to prevent him from destroying those circuits with effectively no useable current limiting.

ATX PSUs should be reserved for PC mainboards and 3D printers (with appropriate protection).

[engrguy42]

Don't even think of going for some ATX PSU lash-up.  You have the budget for a proper dual channel linear bench PSU (and your needs sound modest) so that's what you should buy.

 

Wow. The arrogance.

Gimme a break. ATX supplies are perfect fine for tons and tons of users. Geesh.

Not at all, the OP is asking for PSU suggestions for developing circuits. I My advice was to prevent him from destroying those circuits with effectively no useable current limiting.

ATX PSUs should be reserved for PC mainboards and 3D printers (with appropriate protection).

You're aware that the ATX specification requires internal protective circuits ("supervisors") whose job is to shut off the supply when current exceeds the overcurrent protective level (eg, 240watts/wire), as well as other protective measures?

And y'know, like fuses are, like, real cheap.   
 

[Gyro]

You're aware that the ATX specification requires internal protective circuits ("supervisors") whose job is to shut off the supply when current exceeds the overcurrent protective level (eg, 240watts/wire), as well as other protective measures?

And y'know, like fuses are, like, real cheap.   

Thank you for making my point for me so eloquently 

I said no useable current limit. I am perfectly well aware of ATX PSU specs. 240W/wire doesn't count as in any way effective when you're bringing up or working on the average prototype circuit.

It's a well known and oft-quoted fact that expensive Semiconductors will invariably lay down their lives to protect cheap fuses (fuses are used to prevent fire).

As I say, point made.

[jemangedeslolos]

Hello,

Of course, depending on what you are working on, it could be very very useful to have multiple power supplies.

There is a Rigol DP832A for sale on this forum : https://www.eevblog.com/forum/buysellwanted/rigol-832a-bench-power-supply/

But maybe you can try to find good price on Korad 3005 or similar. I bought 2 of them for 100€ few month ago.
I bought them just because it was cheap but I use them a lot because they are simple, no boot time, fast refresh rate.

[bd139]

The sound of engrguy42's circuits will be "fum" followed by "pop" when the fuse goes.

I'd go for second hand HP / Agilent units myself if you're in the US. Plenty around. Well documented. Very reliable and no nasty surprises. I actually prefer the older ones (HP 62xx series) myself. My main power supply is a TTi PL330QMD which may or may not be available in the US.

If you have the choice between something cheap and new or cheap and second hand and was formerly really expensive, pick the latter every time when it comes to power supplies.

[engrguy42]

For some reason people in these forums apparently have absolutely no ability to comprehend that THEIR needs may not in any way reflect the rest of the world's needs.

There are those who don't use expensive semiconductors. Yes, it's true. Many people buy a shit-ton of cheap semiconductors for $10 to try stuff out. If it melts, reach in the box and get another. Go no, right? But it's true.

And some people actually consider that they can use an inexpensive ATX supply as a simple, additional source of voltage in a crunch, not to deliver spec-shaking accuracy at 30 amps, but merely to get stuff working.

Hard to believe, right? But it's true.

Not everything has to be max rating, femto-amp accuracy. It depends on the user. Different people have different needs.

[bd139]

You can actually seriously injure yourself with an ATX supply if you don't know what you're doing. The 3.3V rail on mine can shift 100 amps easily. You do not want that across a wedding ring or somthing trying to fire up a 3.3V Arduino nano on a breadboard. Also don't want metal vapour in your eyes.  Your point is quite frankly retarded.

[engrguy42]

You can actually seriously injure yourself with an ATX supply if you don't know what you're doing. The 3.3V rail on mine can shift 100 amps easily. You do not want that across a wedding ring or somthing trying to fire up a 3.3V Arduino nano on a breadboard. Also don't want metal vapour in your eyes.  Your point is quite frankly retarded.

You can seriously injure yourself with ANYTHING if you don't know what you're doing or aren't paying attention.

[Gyro]

For some reason people in these forums apparently have absolutely no ability to comprehend that THEIR needs may not in any way reflect the rest of the world's needs.

There are those who don't use expensive semiconductors. Yes, it's true. Many people buy a shit-ton of cheap semiconductors for $10 to try stuff out. If it melts, reach in the box and get another. Go no, right? But it's true.

And some people actually consider that they can use an inexpensive ATX supply as a simple, additional source of voltage in a crunch, not to deliver spec-shaking accuracy at 30 amps, but merely to get stuff working.

Hard to believe, right? But it's true.

Not everything has to be max rating, femto-amp accuracy. It depends on the user. Different people have different needs.

If you're going to start arguing on this forum that an ATX PSU is the correct way to bring up a prototype circuit, then you're going to fall on your ass. As BD139 points out, the available currents can be hazardous.

Your lack of understanding of how to prototype circuits is disturbing. Decent current limit is essential.

[bd139]

Some ATX fun... this one made me snigger a bit to be frank. Just to illustrate.

https://www.reddit.com/r/WatchPeopleDieInside/comments/g0420s/pc_build_does_not_go_as_planned/