Author Topic: 3 channel PSU without problems (Read 6833 times)

Jan Audio · « **on:** March 13, 2019, 04:30:30 pm »

I have this Peaktech 1 channel PSU ( 6225a ).
The display was showing all LEDS flashing, so the shop repaired it, and got no new warranty.
It has been broken again, if i had new warranty they should have repaired it.
This is against my rules, so i am advicing you : NEVER BUY ANY PEAKTECH.
Ok the display is flashing, the PSU is still working, it would be easy to take another chance and buy 1 more of the same PEAKTECH 6225a to form a dual supply.

I need a 3 channel PSU from high quality.
I need -15v, +15v and switchable 5v or 3,3v.

The only thing i like to buy is a R&S HMC8043, it cost very much.
For the rest i only see problems, i youtubed some cheaper brands, and i only get error movies, i dont want these chinese shit again.
The thing is i dont use all the fancy stuff in the HMC8043, i only like to power my circuit and have the milliamps readable per channel.
Those newer R&S ( made in malaysia ) had also big problems, they are not really cheaper either.

What type 3channel PSUdo you advice is worth the money ?

rsjsouza · « **Reply #1 on:** March 13, 2019, 05:01:32 pm »

Despite the initial hurdles that were fixed by Keysight and their firmware, my Keysight E36312A has been quite a great performer.

It has some nuisances, such as the fan that runs continuously, but I can live with that as long as I power down my bench after a day of work.

maginnovision · « **Reply #2 on:** March 13, 2019, 05:05:01 pm »

My only 3 channel PSU is the rigol dp832A. My only problem so far is the inability to completely lock down the front panel. Results in people sometimes turning channels off or on that shouldn't be.

Jan Audio · « **Reply #3 on:** March 13, 2019, 05:23:56 pm »

Thanks

The Keysight E36312A is as pricey as the R&S HMC8043, and im not a fan fan.
The rigol dp832A is also pricey, and not trustworthy for me.

For that money (i dont have) i would buy the HMC8043.
I really like my peaktech 6225a exept that its broken,
its small, makes no noise, decent looking.
Why is it crap ?

rsjsouza · « **Reply #4 on:** March 13, 2019, 06:13:26 pm »

Quote from: Jan Audio on March 13, 2019, 05:23:56 pm

The Keysight E36312A is as pricey as the R&S HMC8043, and im not a fan fan.
The rigol dp832A is also pricey, and not trustworthy for me.

I agree the Keysight is very expensive, but its fan is not noisy at all.
According to reports from experienced users around here, the Rigol is a great performer, has very reasonable quality and is quite inexpensive for the amount of features and power.

Quote from: Jan Audio on March 13, 2019, 05:23:56 pm

For that money (i dont have) i would buy the HMC8043.
I really like my peaktech 6225a exept that its broken,
its small, makes no noise, decent looking.
Why is it crap ?

It is crap because some minimal level of quality and reproducibility across a production run costs money. The design may even be good, but the quality erodes during production of such units.

I think you need to better set your expectations. You ask which 3 channel power supplies are worth the money but I think you wanted to ask which 3 channel power supplies can have good quality and be had for cheap. If you don't have access to the used market, you will be hard pressed to fulfill all the conditions.

colorado.rob · « **Reply #5 on:** March 13, 2019, 06:25:38 pm »

Siglent SPD-3303X-E?

https://store.siglentamerica.com/product-category/dc-power-supply/spd3303x-series/

tautech · « **Reply #6 on:** March 13, 2019, 07:53:52 pm »

Quote from: colorado.rob on March 13, 2019, 06:25:38 pm

Siglent SPD-3303X-E?

https://store.siglentamerica.com/product-category/dc-power-supply/spd3303x-series/

Yep, good fit.

To the OP, if watching any old videos on these please be aware the main LCD readout information was changed in firmware to give better info to the user.
Only one of the Siglent websites shows how it looks now on their webpage:

kripton2035 · « **Reply #7 on:** March 13, 2019, 07:56:06 pm »

old used hameg 7042 or 8042 are rock solid. you can get some on ebay quite often in europe.

nctnico · « **Reply #8 on:** March 13, 2019, 08:52:00 pm »

Quote from: Jan Audio on March 13, 2019, 04:30:30 pm

I need a 3 channel PSU from high quality.
I need -15v, +15v and switchable 5v or 3,3v.

What type 3channel PSUdo you advice is worth the money ?

I like my Keysight E36313A. The first batch did had a problem but Keysight took all of them back and fixed it for free. It has a fan but you can't hear it. What tipped the scale for me is that the E36313A (like the E36312A) has two current measurement ranges and the readout for both current and voltage is very accurate. The low current range is accurate to about +/-10uA with a 1uA resolution.

Jan Audio · « **Reply #9 on:** March 14, 2019, 02:47:18 pm »

I did not see any second hand, exept still expensive.
I buy second hand for lower then half the cheapest new price, i better not buy second hand at all, always buying broken stuff.
I dont buy any siglent for sure, and this time also no chinese stuff no more, i almost forgot, thanks for reminding.

Jan Audio · « **Reply #10 on:** March 14, 2019, 02:49:30 pm »

Quote from: rsjsouza on March 13, 2019, 06:13:26 pm

It is crap because some minimal level of quality and reproducibility across a production run costs money. The design may even be good, but the quality erodes during production of such units.

So i could take another gamble for €75,-
Do you expect i will receive another soon broken unit ?

rsjsouza · « **Reply #11 on:** March 14, 2019, 05:35:27 pm »

Quote from: Jan Audio on March 14, 2019, 02:49:30 pm

Quote from: rsjsouza on March 13, 2019, 06:13:26 pm
It is crap because some minimal level of quality and reproducibility across a production run costs money. The design may even be good, but the quality erodes during production of such units.

So i could take another gamble for €75,-
Do you expect i will receive another soon broken unit ?

Jan, I really can't tell for sure. As you said, it is a gamble.

However, depending on where you purchased it you could potentially see if there is the ability to issue free returns. If the power supply fails under the same conditions, you could always return it.

I recall an old thread where folks discuss a very similar power supply as yours (at least it has the same looks) and it is highly regarded there.
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/
https://www.eevblog.com/forum/testgear/mch-k305d-cheap-switching-lab-power-supply/

The OEM is different, and that may make a difference in quality: MCH K305D, also seen as LW-K305D.

nctnico · « **Reply #12 on:** March 14, 2019, 07:29:05 pm »

Quote from: rsjsouza on March 14, 2019, 05:35:27 pm

I recall an old thread where folks discuss a very similar power supply as yours (at least it has the same looks) and it is highly regarded there.
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/
https://www.eevblog.com/forum/testgear/mch-k305d-cheap-switching-lab-power-supply/

Calling it 'highly regarded' isn't exactly the truth. Some are outright dangerous due to poor wiring and it pushes out a lot of EMI noise.

rsjsouza · « **Reply #13 on:** March 14, 2019, 07:39:24 pm »

Quote from: nctnico on March 14, 2019, 07:29:05 pm

Quote from: rsjsouza on March 14, 2019, 05:35:27 pm
I recall an old thread where folks discuss a very similar power supply as yours (at least it has the same looks) and it is highly regarded there.
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/
https://www.eevblog.com/forum/testgear/mch-k305d-cheap-switching-lab-power-supply/
Calling it 'highly regarded' isn't exactly the truth. Some are outright dangerous due to poor wiring and it pushes out a lot of EMI noise.

I missed your post in the first thread. I guess you are right; the high frequency noise is not that great. The other factors are not that terrible, provided you inspect the supply beforehand.

To the OP, I also have the AFR PS3005 - a clone of the QJE PS3005 power supply. It is ok for general purpose work and I frequently stress it closer to its limit, although under these conditions I am not too concerned about ripple and noise.

AlanS · « **Reply #14 on:** March 15, 2019, 02:12:45 am »

I too like my Keysight E36313A - I needed it urgently after a lightning strike took out my H24005 and they are not being made anymore. As testament to their value, I've only seen one come on to the used market since the strike.

I understand that cost issue and would recommend the H25005 that Prasimix is working on. But I suspect it's a ways away. I'm sure it will be worth the wait though - the H24005 is fantastic.

0culus · « **Reply #15 on:** March 15, 2019, 02:18:15 am »

I like the Keithley 2231A, got it new. It doesn't have quite as many features as the highest model so it was considerably cheaper. It gives you 30V/3A out of channels 1 and 2, 5V/3A out of channel 3. Can connect 1 and 2 in series or parallel to get 60V or 6A, respectively. Easy to save and recall configurations too.

nctnico · « **Reply #16 on:** March 15, 2019, 03:03:48 pm »

Quote from: blueskull on March 15, 2019, 02:23:21 am

Register Keysight's lottery and pray. One if its prizes is 36313A.

I don't think Dutch people are included in Wave2019.

bd139 · « **Reply #17 on:** March 15, 2019, 06:25:06 pm »

Don't know how much current you need but look at second hand HP/Agilent/Keysight E3630A.

Silent, reliable, digital readout.

nctnico · « **Reply #18 on:** March 15, 2019, 06:41:56 pm »

Quote from: bd139 on March 15, 2019, 06:25:06 pm

Don't know how much current you need but look at second hand HP/Agilent/Keysight E3630A.

But it doesn't have current limiting. IMHO that is a crucial feature for a bench power supply. When I bring up a new circuit I set the limit to a low value to prevent any damage due to whatever error.

bd139 · « **Reply #19 on:** March 15, 2019, 07:01:56 pm »

As I said in another thread a lot of the time your DUT is dead from the output cap before the power supply feedback loop does anything about it. Have destroyed a few things with current limits turned on even to low values.

Also it does have a hard current limit and foldback as well.

nctnico · « **Reply #20 on:** March 15, 2019, 07:23:42 pm »

Quote from: bd139 on March 15, 2019, 07:01:56 pm

As I said in another thread a lot of the time your DUT is dead from the output cap before the power supply feedback loop does anything about it. Have destroyed a few things with current limits turned on even to low values.

No. Not if you switch the PSU output on with the load attached. That way the current limit tracks the voltage ramp-up. I never attach a DUT to a PSU output which is on. First connect the DUT then switch the output on. All my PSUs have output enable switches (except one which I have not modified yet).

2N3055 · « **Reply #21 on:** March 15, 2019, 07:30:22 pm »

How about TTi PL303QMT? Does anybody have it?

colorado.rob · « **Reply #22 on:** March 15, 2019, 07:44:39 pm »

Quote from: 2N3055 on March 15, 2019, 07:30:22 pm

How about TTi PL303QMT? Does anybody have it?

I have the TTi MX100TP and am very happy with it. Certainly well worth the money to me. I suspect it it out of OP's budget but little has been said of budget other than the Hameg PSU being too expensive. If the R&S 8043 is outside of the budget, then I suspect the AIM/TTI ones are as well.

Jan Audio · « **Reply #23 on:** March 16, 2019, 02:18:58 pm »

Quote from: nctnico on March 15, 2019, 06:41:56 pm

But it doesn't have current limiting. IMHO that is a crucial feature for a bench power supply. When I bring up a new circuit I set the limit to a low value to prevent any damage due to whatever error.

Indeed, this i forgot to mention.
I also looked and some models have the 5v channel also no current limiting.
I like to have all 3 channels current limiting.

Those TTi are very expensive also.

bd139 · « **Reply #24 on:** March 16, 2019, 02:37:09 pm »

Look at second hand PL320/PL330 supplies. They are dirty cheap and come in single double and triple varieties.


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Author Topic: 3 channel PSU without problems (Read 6833 times)

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