Sh#t power supplies...

[bingo600]

http://www.ebay.com/itm/HP-6114A-Precision-Power-Supply-020V-2A-2040V-1A-65335399-/310873020499

$10. 

4 days left, and the price is likely to go up now that I've posted it here, but this is a good supply and it's known-working at least to some degree.  Great supply.

You worthless piece of shit  . Sorry if that's harsh, but I was intently watching that supply hoping to snag it for a good deal. Well, I have one already, better let this one find a good home.

That was not a needed comment

/Bingo

[bingo600]

People in EU don't be desperate here you can buy those power supply's

http://www.woutersenwouters.be/products/power-supplies

At those prices? Let the desperation continue!

Agreed almost new prices

/Bingo

[robrenz]

http://www.ebay.com/itm/HP-6114A-Precision-Power-Supply-020V-2A-2040V-1A-65335399-/310873020499

$10. 

4 days left, and the price is likely to go up now that I've posted it here, but this is a good supply and it's known-working at least to some degree.  Great supply.

You worthless piece of shit  . Sorry if that's harsh, but I was intently watching that supply hoping to snag it for a good deal. Well, I have one already, better let this one find a good home.

Don't you realize that everyone that is interested has email notification set up for these things? Thinking no one but you realized this thing existed until Rigby posted it is naïve.

[mrflibble]

Don't you realize that everyone that is interested has email notification set up for these things? Thinking no one but you realized this thing existed until Rigby posted it is naïve.

I should hope he realized that... But it has to be said that goodies that are plastered all over a forum generally don't go for the low low prices you can sometimes get with a lucky snipe.

[Rigby]

You worthless piece of shit  .

Damn, dude.  A simple "I was hoping to snipe that, now everyone knows," would have sufficed.  Edit: by the way, not everyone will react as calmly to this as I have.  Beware your reactions in the future if you wish to gain respect from anyone.  You lost a lot of respect from me with that comment.  My own mother has called me worse, so my skin is a bit thicker, but I don't talk to her anymore because of things like this.  Don't be surprised if continued behavior like this results in less assistance in this forum later

Don't you realize that everyone that is interested has email notification set up for these things? Thinking no one but you realized this thing existed until Rigby posted it is naïve.

Yep.  Carefully crafted searches set to email you are the very best way to find these things.  Now, just like the power supply, anyone reading that didn't know about this now does.

[nanofrog]

http://www.ebay.com/itm/HP-6114A-Precision-Power-Supply-020V-2A-2040V-1A-65335399-/310873020499

$10. 

4 days left, and the price is likely to go up now that I've posted it here, but this is a good supply and it's known-working at least to some degree.  Great supply.

You worthless piece of shit  . Sorry if that's harsh, but I was intently watching that supply hoping to snag it for a good deal. Well, I have one already, better let this one find a good home.

You're not the only one interested, I'm sure. 

[TMM]

The whole colour LCD wannabe voltage reference precision thing is a wank. Not much point having 1mV resolution when most of the time your leads are going to be dropping orders of magnitude more than that.

I use a $300 chinese built linear supply with analog knobs and 7-seg displays (0.1V resolution). If i need a precise voltage out comes the multimeter... and it's measured at the end of the leads. The only feature that would have me spend over $1k on a powersupply is LXI/ethernet and even then i probably wouldn't end up using it as my main supply because it'll probably have a wanky non user friendly interface.

My 2c.

[Rigby]

The whole colour LCD wannabe voltage reference precision thing is a wank. Not much point having 1mV resolution when most of the time your leads are going to be dropping orders of magnitude more than that.

I use a $300 chinese built linear supply with analog knobs and 7-seg displays (0.1V resolution). If i need a precise voltage out comes the multimeter... and it's measured at the end of the leads. The only feature that would have me spend over $1k on a powersupply is LXI/ethernet and even then i probably wouldn't end up using it as my main supply because it'll probably have a wanky non user friendly interface.

My 2c.

One thing that I really dig about my Power Designs 3650-S is that it has sense wires, and can do Kelvin 4-wire measurement of the actual power being delivered.  I guess that's what makes it a precision supply over a regular supply.

Like you, though, I don't have any need for this precision at all.  I'm sure there are applications which require perfect power, but I'm not working on those.  The analog meters on my supplies all provide enough precision for the hobby work I'm doing.

It is TOO EASY to get into the hobby of upgrading test gear, isn't it? 

[robrenz]

It is TOO EASY to get into the hobby of upgrading test gear, isn't it?

I have no idea what you are talking about

[HiTech]

Don't mess around with other brands- just go for HP Power Design, Trigon, Sorensen. They all have models with dual/triple outputs are are bulletproof.  Yes they will be used and the better deals are online auctions but they are plentiful and shop wisely.

[Sbampato12]

I had got 2 E3649 from hp/agilent/key...
They are to me like a canon shot to kill a fly, but you know. When I visited the website, and saw they were for sale for just US$300,00, new units, with 5 years warranty, and 3 years calibrated, I couldn't resist. I just bought the 2 they had on stock. I think I did a good purchase
I can't find nothing wrong with them. Very precise, ease to use. And it got the programable functions, but only by GPIB...

[TMM]

One thing that I really dig about my Power Designs 3650-S is that it has sense wires, and can do Kelvin 4-wire measurement of the actual power being delivered.  I guess that's what makes it a precision supply over a regular supply.

Even with sense wires there is only so far you can go because of the inductance in the leads. Best off just re-regulating locally on the device if it needs to be precise imo

[Rigby]

One thing that I really dig about my Power Designs 3650-S is that it has sense wires, and can do Kelvin 4-wire measurement of the actual power being delivered.  I guess that's what makes it a precision supply over a regular supply.

Even with sense wires there is only so far you can go because of the inductance in the leads. Best off just re-regulating locally on the device if it needs to be precise imo

I'm not sure how much I need to worry about sense lead inductance on a DC supply.

The manual does recommend a shielded twisted pair for the sense wires, though, so what do I know?

[TMM]

The sense feedback will compensate for the lead resistance but in practice will never fully compensate for the inductance so transient performance will still suffer.

[GreyWoolfe]

UnknownVertigo, I don't know what country you live in.  I have the Agilent E3610A and like it very much.  Here is a link for 4 units for $440 USD and another $99 for shipping.  http://www.ebay.com/itm/Agilent-E3610A-8-15-V-3-2-AMP-Dual-Range-Power-Supply-qty-4-units-/310753946643?pt=LH_DefaultDomain_0&hash=item485a60ec13
Four will stack neatly on top of each other and the footprint is pretty good.  I wish I had the disposable cash to buy them myself.

[jadew]

I don't know why you guys are hellbent on old crusty power supplies. For today's hobbyist, they suck.

Why you ask? Well, because projects are different than what they used to be 50 years ago. You need AT LEAST mA readings from the supply (and I mean digital display), otherwise you'll end up having to use a separate DMM for that. Same goes for voltage. Why have two extra pieces of gear just so you get something that a decent supply should already provide given today's technology state?

As for the cheap agilent ones, they suck in two ways: 1) 10 mA reading resolution and 2) no way to set the current while you're outputting stuff. You have to push that damn button that basically shorts the output to ground. That's... impractical to say the least and if you want 1 mA resolution you'll have to short them yourself, with your DMM (awesome! ... not).

Now... aside from mA reading, you need mA (edit: output) resolution! if you can go lower than that, that's even better!

Also, the bench supply needs to be programmable and have a way for you to output the readings to the PC so you can analyze and characterize stuff, as you advance (even as a hobbyist) this becomes a need more and more often.


That being said, regardless of how simple linear supplies are and how easy it is to make the digital side, there seems to be a shortage of good bench supplies out there, but I wouldn't go as far as recommending super old supplies or old designs that are simply unsuitable for what your usual noob or hobbyist does on his bench today.

[c4757p]

I have yet to require mA resolution on a power supply, and I suspect this is similar to the people who think they need an 8 digit DMM.

mV resolution is nice for finicky digital stuff - Power Designs FTW.

[jadew]

I have yet to require mA resolution on a power supply, and I suspect this is similar to the people who think they need an 8 digit DMM.

You'll need mA resolution the moment you start designing things that have to run on batteries.

Edit: The mA resolution (and lower) for output is useful for testing low power loads, like LEDs.

[c4757p]

I have a DMM for that. Why do I need do combine them?

[echen1024]

I don't know why you guys are hellbent on old crusty power supplies. For today's hobbyist, they suck.

Why you ask? Well, because projects are different than what they used to be 50 years ago. You need AT LEAST mA readings from the supply (and I mean digital display), otherwise you'll end up having to use a separate DMM for that. Same goes for voltage. Why have two extra pieces of gear just so you get something that a decent supply should already provide given today's technology state?

As for the cheap agilent ones, they suck in two ways: 1) 10 mA reading resolution and 2) no way to set the current while you're outputting stuff. You have to push that damn button that basically shorts the output to ground. That's... impractical to say the least and if you want 1 mA resolution you'll have to short them yourself, with your DMM (awesome! ... not).

Now... aside from mA reading, you need mA (edit: output) resolution! if you can go lower than that, that's even better!

Also, the bench supply needs to be programmable and have a way for you to output the readings to the PC so you can analyze and characterize stuff, as you advance (even as a hobbyist) this becomes a need more and more often.


That being said, regardless of how simple linear supplies are and how easy it is to make the digital side, there seems to be a shortage of good bench supplies out there, but I wouldn't go as far as recommending super old supplies or old designs that are simply unsuitable for what your usual noob or hobbyist does on his bench today.

Uh huh. And why do I bother with a 70 MHz oscilloscope anyways. Everyone knows that to get good measurements, I need at least 10GHz.

[rdl]

You'll need mA resolution the moment you start designing things that have to run on batteries.

You are try to use the power supply as a meter, not what it's for.
For that you need a multimeter that reads microamps.

[jadew]

Uh huh. And why do I bother with a 70 MHz oscilloscope anyways. Everyone knows that to get good measurements, I need at least 10GHz.

If you were using it to analyze 10Ghz signals, then yes, otherwise I don't see the point of this comment.

[jadew]

You'll need mA resolution the moment you start designing things that have to run on batteries.

You are try to use the power supply as a meter, not what it's for.
For that you need a multimeter that reads microamps.

So in order to use one of those old supplies I need 2 DMMs attached to it on top of the ones I already need to check the circuit under test?

Edit: And yes, it should behave as a meter as well, that's why they are called bench supplies and not wall adapters.

Edit 2: Again, today, we can do those readings extra cheap, so why not?

[echen1024]

Uh huh. And why do I bother with a 70 MHz oscilloscope anyways. Everyone knows that to get good measurements, I need at least 10GHz.

If you were using it to analyze 10Ghz signals, then yes, otherwise I don't see the point of this comment.

My point is, many of us cannot afford the high end power supplies that you are pointing at. We must live within our means, and purchase what we can afford. Therefore, we will buy power supplies like the Agilent E3610A, which is a high quality, Agilent, with a good feature set and it won't break the bank. Sure, your Chinese POS might let you set voltage and current to 1mV/mA, but do you really trust the output?

[c4757p]

Of course you don't.

We think you are being silly and claiming things are necessary when they are far from it. If a noob can't make do with a basic power supply, he has a real problem, and it ain't the gear.

There is a difference between "want" and "need", and I'm not sure you understand it.