HP / Agilent E3632a 120W Supply

[Madsaaby]

Hello guys

Just picked up a HP E3632a 0-15V 7A / 0-30V 4A Power Supply.
Price: 225 $ fully working  Feels like stealing 

I will post some photos taken inside it, but here is one with the cover still on

-Mads

Edit: Here is a video of the supply in CC mode. Testing with an LED to see that it regulates fast enough, not to blow it
I couldn't resist blowing the arse out of the LED of cause
http://youtu.be/8hpV46RcC2E 

[Monkeh]

Dude, your wires are square. The hell have you been smoking?

[Madsaaby]

Dude, your wires are square. The hell have you been smoking?

Haha, only a bit of the solder fumes today 

Homemade from leftover speaker cable Actually working very nice Takes a shitload of current!..

[SeanB]

Wonder how silver coated speaker cable will effect power delivery? Must pull out the braided stuff to use with my PSU and see.....

[Monkeh]

Wonder how silver coated speaker cable will effect power delivery? Must pull out the braided stuff to use with my PSU and see.....

It'll be FASTER!! CLEANER!! BETTER!!

Excuse me while I go bleach my brain.

[SeanB]

i didn't pay for it...... It was a freebie.

Then again the jump leads I have are rated at 8kA for 30 seconds. not sure about the clamp terminals though, i think they will evaporate at that current. They have a very low resistance for sure.

[peter.mitchell]

i didn't pay for it...... It was a freebie.

Then again the jump leads I have are rated at 8kA for 30 seconds. not sure about the clamp terminals though, i think they will evaporate at that current. They have a very low resistance for sure.

on a somewhat related note, the other day I jump started an old truck with a bad starter, using another truck and took a massive chunk out of the clamps on the leads,  the leads were very hot and soft too,  I wouldn't be surprised if they were pulling a few k amps.

[SeanB]

The cabling I used was starter cable, definitely capable of this current.......

Found an offcutt of van Den Hul speaker transmission line ( what else do you call a cable that has controlled impedance and is flat and spaced) and am using this nice ultra flexible silver plated wire as a lead. 6A and it is fine, nice and flexible, and I crimped lugs on both ends along with a coloured heatshrink to identify them.

[Madsaaby]

... I will post some photos taken inside it, but here is one with the cover still on ...

So, here we go

Front:


Back:


Cover frame, with nice "hold in place when loosend" screws, I like that


The first thing to catch your eye is that massive transformer. Expected, since this is a linear supply.


Underneath :


Heat sink + the reason why this sounds like a 747 taking off..


overview of the visible components.


Some beefy capacitors, sorry not the best pic.


Weee, a LM317t + a LM337


Hmm..


Some power resistors, looks like current sense to me ?!


Now, that's a REAL power switch, not some soft latching rubbish


Mains input / fuse / tab select (i think it's capable of 120v as well as 230v) And that 747 exhaust again ... -.-


That's a thing of beauty, a joy forever As a well known person would say


Hmm, yup.


Wonder why they didn't use 105c caps, but then again they are all still fine..


Looks like that insert is changeable to set it to 120v ?


That's a nice fuse holder!


Ay, screw that..


And YAY, still works Set to 3A and spot on +- 0.1%


Set to 10V, spot on.


Set to 10V, measures 10.002 I'd call that a pass.


Set to 3A, 3.006 ... Think i could live with that


-Mads

[Monkeh]

Odd fan. Looks like it's in backwards, but it can't be or the dust would be on the other side.

E: Then again, the blade profile looks wrong.. Just check that's actually in the right way.

[cwalex]

Odd fan. Looks like it's in backwards, but it can't be or the dust would be on the other side.

E: Then again, the blade profile looks wrong.. Just check that's actually in the right way.

Looks right to me. All the fans I've seen blow air in the direction of where the stator is attached to the plastic housing. (I think I got my terminology right please correct me otherwise)

[Monkeh]

Odd fan. Looks like it's in backwards, but it can't be or the dust would be on the other side.

E: Then again, the blade profile looks wrong.. Just check that's actually in the right way.

Looks right to me. All the fans I've seen blow air in the direction of where the stator is attached to the plastic housing. (I think I got my terminology right please correct me otherwise)

Yes, and normally you'd be blowing air out the back of equipment, not sucking in it.

[BravoV]

Not claiming an expert though, but here what I'm thinking, when blowing IN, the disadvantage is heating "other" internal components unnecessarily, and the heat will vary with the load, light load = less heat, high load = less efficient = higher air temperature "inside" the case.

Even though precision components have low TC like the voltage reference and precision resistor, believe they just don't like to be exposed to continuous temperature fluctuation,  also the word "Thermal Hysteresis" came into mind, might affect it's long term stability, again CMIIW.

Blowing out doesn't have this weakness since the room temperature is unlikely to fluctuate as much as the power transistor/heatsink part, the other internal precision parts will have better temperature stability.


PS : If this is your fav bench top psu, mind participate in the Bench PSU thread, just click my sig at the bottom left. 

[Monkeh]

Not claiming an expert though, but here what I'm thinking, when blowing IN, the disadvantages is heating "other" internal components unnecessarily, and the heat will vary with the load, light load = less heat, high load = less efficient = higher air temperature "inside" the case.

Even though precision components have low TC like the voltage reference and precision resistor, believe they just don't like to be exposed to continuous temperature fluctuation,  also the word "Thermal Hysteresis" came into mind, might affect it's long term stability, again CMIIW.

Blowing out doesn't have this weakness since the room temperature is unlikely to fluctuate as much as the power transistor/heatsink part, the other internal precision parts will have better temperature stability.

And a whole host of other things related to actual airflow. Not to mention most equipment exhausts out the back, so you'd be sucking in higher temperature air than from the front.

So, why's that fan sucking air in from behind?

[BravoV]

And a whole host of other things related to actual airflow. Not to mention most equipment exhausts out the back, so you'd be sucking in higher temperature air than from the front.

So, why's that fan sucking air in from behind?

Yeah, I agree, most equipments, especially psu's fan mostly exhaust if only single fan.

Since the OP bought it used, maybe someone / previous owner had it installed backward when tinkered with it ? 

[cwalex]

Odd fan. Looks like it's in backwards, but it can't be or the dust would be on the other side.

E: Then again, the blade profile looks wrong.. Just check that's actually in the right way.

Looks right to me. All the fans I've seen blow air in the direction of where the stator is attached to the plastic housing. (I think I got my terminology right please correct me otherwise)

Yes, and normally you'd be blowing air out the back of equipment, not sucking in it.

Hmm, good point!

[Madsaaby]

Odd fan. Looks like it's in backwards, but it can't be or the dust would be on the other side.

E: Then again, the blade profile looks wrong.. Just check that's actually in the right way.

I didn't give that a thought at the time, but I think you are right. It does indeed look wrong. I can confirm that the fan is indeed blowing air inwards. But maybe HP did that on purpose, it seems like, they like to blow air directly at the heat sinks. If you take a look at the HP E3634a it looks even funnier in my opinion, with the fan in the middle of the unit, to spread heat everywhere..

But don't know, maybe someone DID flip it around..

-Mads

[Rick]

It's blowing outwards, therefore the hot air gets out of the device by the holes passing around the heatsinks. The air is not blown inwards as far as I understand from Shahriar's video. The fans I have seen so far are better to blow air than to suck air so it makes sense.  It would cause a better circulation of air than a low air aborption outwards, wouldn't it?
Or did I get it wrong and the fan blows air in the direction of the front panel???

[Madsaaby]

It's blowing outwards, therefore the hot air gets out of the device by the holes passing around the heatsinks. The air is not blown inwards as far as I understand from Shahriar's video. The fans I have seen so far are better to blow air than to suck air so it makes sense.  It would cause a better circulation of air than a low air aborption outwards, wouldn't it?
Or did I get it wrong and the fan blows air in the direction of the front panel???

Yes, in the E3634a, it's blowing outwards. but it was the placement of the fan that was wondering me, the hot air will heat up components on its way out.. In the E3632a the fan is mounted in the chassis, but blowing inwards, which seems strange and will also heat up the sorounding components, as people mentioned.. But don't know guess HP / Agilent know what they are doing

-Mads

[Rick]

I see, I read fast and missed that. Sorry.
By the way there is also a E3634a out there at $189 but it is broken and from a well known seller:) So it is scary.
I have the feeling that it will be easy to fix but...

[Madsaaby]

I see, I read fast and missed that. Sorry.
By the way there is also a E3634a out there at $189 but it is broken and from a well known seller:) So it is scary.
I have the feeling that it will be easy to fix but...

No problem
That could be worth a try, if one is in the need of a new PSU. 189 ain't that much And those supplies are pretty awesome
I recommend it, thumbs up

[Rick]

I have a cheap Chinese one: AATech or something like that:)
Nothing comparable to these... I don't have experience in repairing stuff that's why I am scared.
I asked him to run a self test. This is a nice guy but pretends to know nothing, that's why it is risky and annoying to buy from him, I believe.
By the way I have realized that it is more advantageous to buy mains powered units from Australia, because they are 220V/50Hz.
I think this one is 110V don't know about the Hz though.