Choice of 30V, 10A laboratory power supply up to 300PLN - request for recommendations

I want to buy some good 30V 10A lab/workshop power supply up to the price of 300£.
I've already had my eye on a few but came across a test video and have a dilemma.
Who can recommend me something good ?
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dawid1346 wrote:

good 30V 10A laboratory/workshop power supply for the price of £300.

Conflicting conditions, used only.

Unfortunately, you won't be able to buy anything new for that kind of money, and DIY won't work either because the cost of components will exceed 300£ (especially nowadays).

The only thing left is to hunt quietly at auctions, sometimes really nice power supplies appear at a decent price.
Often a whole batch of some power supplies fall into stock and the price is "to go".
It's worth looking for Philips, Xantrex, Elind, unfortunately 10A current doesn't happen often.

I would buy a good quality used power supply, something branded + for high currents fashion something from Chinese modules on switching power supplies.

The power of 300W in linear power supplies is above average and there are few such power supplies, a switching power supply for this power is easier to construct, there are more of them, but such a design has some drawbacks and this is the cause of the problems you saw in the video.

dawid1346 wrote:

I already had a few in mind but I came across the video of the tests and I have a dilemma.

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The truth is that nothing comes for free and I am not just talking about price, when some parameters are improved others deteriorate, you have to make a compromise choice. The disadvantages shown in the video in certain applications are acceptable.


I wonder how much of this is a real need for a 10A capacity and how much is "I want more, just in case", what will you be using it for?
When I was a beginner I thought a power supply needed to be as powerful as possible, today I use something different for powering current hungry circuits, something different for low power circuits.

Actually, the 10A is just in case, but when I think about it, 5A is enough for me

AVE...

Let me recommend products from Alliexpress. A Wanptek KPS3010DF power supply that meets the author's requirements costs ~112USD or about 487PLN. The Wanptek KPS305DF is an expense of ~69USD or just under 300PLN. These are switch mode power supplies with fairly decent performance and reasonable build quality.

In my humble opinion, in the practice of an amateur electronics technician, it is more useful to have two power supplies of up to 5A rather than one for 10A. Ba, I'm considering building a precision power supply with less than 10V and up to 2A current, because a lot of electronics operate at such voltages, especially battery-powered circuits.

Urgon wrote:

.... I'm considering building a precision power supply with less than 10V and up to 2A current, because a lot of electronics operate at such voltages, especially battery-powered circuits.

Years ago: power supply trafo from a VELA TV, uA723 stabiliser, BC211, 2N3055 and some RC trinkets, 150 divisions analogue indicator and hence a range of 3-15V (when regulating from zero you have to complicate the circuit a little by a few elements) and the limit set to a fixed 1,5A (it is possible to introduce adjustable limit, but I didn't want to add an extra potentiometer), it has been working perfectly for years and it is the most frequently used one (I also have a few other factory ones), for today the "cost" is the labour and not the cost of elements, I recommend.

AVE...

If I'm building, it's more likely to be something based on the SN1534, but with digital control and digital measurement based on 12-bit ADCs and DACs....

And how do you rate this equipment ?
Link

dawid1346 wrote:

And this equipment how do you rate it ?

Good. Certainly better than impulse in many applications.

If you want to do it your way, a very good material for a home-made high-power laboratory power supply at the moment is the ZS-20 power supply available as new in ham radio shops, or sometimes as a second-hand one on allegro. All you need to do is to bring out multi-turn potentiometers on the panel (or ordinary ones with a range switch) and possibly draw a voltage scale or insert a separate voltmeter. In the original, you will get a control range of 0-16V/0-22A max (tray power 350W), or by replacing both single-voltage rectifiers with gretzos you will get 0-32V/0-11A max. There are also ready-to-use 723 modules-boards, but they are only available on eBay. There used to be such modules still on allegro. At one time, the 723 power packs were very reliable and popular in industrial automation, often in TP S.A. switchboards, for example, and also widely described in various variants in books. Unfortunately, I must admit that now, apart from the ZS and a module from ebay, only a memory remains of them, because the 723 is an excellent chip.

Schematic of the ZS-20
(thyristor optional - throws a fuse in case of an overvoltage)

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Module available on eBay

AVE...

This is the same as most cheap lab and workshop power supplies, only you still have to scrounge up your own meters, transformer and enclosure. It's cheaper and less hassle to buy a ready-made one. Building your own circuit makes sense if you have a specific need that cannot be met by a ready-made "not-for-millions" product, as in my case....

maybe something like this https://www.pepper.pl/promocje/zasilacz-labor...10w-0-30v-0-10a-300w-wysylka-z-cz-5549-527932 ?

If linear then in my opinion a 30V 10A for 300zl is impossible. From a quick look at prices, either a pulsed or 5A max.
Maybe you don't need as much as 10A?

And then there is the question of accuracy requirements, ripple level etc....

Mr. Counter! @Hektar-Zahler This power supply for CB radios comes with a 16 volt crowbar! When changing the rectifier to a Greatz bridge this circuit must be removed!

Remove, or Replace, the D4 zener to a voltage a few volts higher than the maximum range of the adjustment you have made and it will be, say, 18V for the 0-16V range, or 34V for the 0-32V range.

P. S.
As for buying from gotronik - I would advise against it. I have dealt with them and the customer respect in this company is highly unsatisfactory ! For example, after buying a Willem PRO4 ISP programmer, the user gets a bunch of nonsense copied from internet forums on the CD. Or, for example, some devices which have not been produced for many years (such as the Protek D620) are still hanging around on this website to this day and after e-mails on the subject I received downright incomprehensible gibberish in reply.

Urgon wrote:

AVE...

As I will be building, rather something based on SN1534, but with digital control and digital measurement based on 12-bit ADCs and DACs...

Tastes are not discussed but 12-bit converter for voltage and current measurement in power supply replacing battery supply........Greetings.

AVE...

cirrostrato wrote:

Urgon wrote:

If I build, it's more likely to be something based on the SN1534, but with digital control and digital measurement based on 12-bit ADCs and DACs....

Tastes are not to be discussed but a 12 bit ADC to measure voltage and current in a power supply replacing a battery supply........Greetings.

What do you dislike about it? For me, the resolution of the settings and measurement to 2mV/500µA is completely sufficient. There is also no problem to use a 14-bit ADC for current measurement, which would give a resolution of 125µA, or even a 16-bit one to have a resolution of 31.25µA. I, however, would sooner use 12-bit ADCs and a programmable amplifier, because with a consumption of ~1A a resolution of up to 31.25µA is not necessary for me for anything practical. Therefore, by adding, for example, the MCP6G01 I can have a resolution of 500µA for currents up to 2.048A, 50µA up to 204.8mA and 10µA up to 4.096mA. And so the precision of this power supply will be limited by the quality and drift of the reference voltage, the errors and drifts of the operational amplifiers and the ADCs and DACs....

Back on topic, fellow @dawid1346 does not need a 10A power supply. I would advise buying something reasonable with typical 30V/5A values, maybe even two units, or a second 15V/3A power supply. Top it off with a reasonably reasonable multimeter, like the Aneng AN870, and you'll be a mate happy.

The fundamental question is: what specifically does the colleague need the power supply for, and what does he expect from it?

I have been using one since last year; https://www.elektroda.pl/rtvforum/topic3803317.html and I am very satisfied.

I have two Korads in the works and it is fab for toys up to 24V, higher than that I don't know because I haven't played with .

dawid1346 wrote:

And this equipment how do you rate ?
Link

It is possible that it will be ok. It is an RXN and it is possible that it has CC mode. I once bought a PXN. In the description it had a CC and CV mode, but it turned out that the CC was an adjustable cut-off and not an adjustable current limitation

@Wawrzyniec And the displays die very quickly - they lose segments.

dawid1346 wrote:

And this equipment how do you rate ?
Link

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Read this thread:
https://www.elektroda.pl/rtvforum/topic3863091.html
and specifically my last post in this thread.

Generally the power supply for simple workshop work is ok, but it failed that "diode test" for me once.

It should also be noted that when working on current limitation, slight interference (pins) is also visible in the output voltage waveform.
The fan is quite noisy but fortunately does not run all the time. The included cables are a misunderstanding in my opinion, not only are they quite short, their quality and cross-section is so-so.
But as a new power supply this rather has the right price/quality ratio.

Today the RXN-305D arrived at my home.
I must say that I am quite satisfied.
It is very nice to set parameters on it, the current limitation works well, the diode test at different voltages and the diode is alive.
In the video (3:55), in order to set the current limitation, you have to short the terminals, but with my RXN-305D you don't have to do that, without a short circuit or connected receiver it shows zero, but when I turn the potentiometer, the set parameters are displayed.

Link

The wires are a bit lame but I don't think this is a problem.
As for me it is ok and so far I can recommend it. We will see how long it lasts.

dawid1346 wrote:

but when I turn the potentiometer
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This is not a potentiometer but an encoder. We'll see how long it will live in Chinese manufacture. This power supply already has a digital control, which is why you can set the current limit without shorting the leads. Besides, the power supply "remembers" the last voltage and current settings after switching off, even if you turn the encoders, which is also sometimes a useful thing. And that's probably the end of the advantages of digital control in this particular power supply.
Because while the potentiometers in the previous version of these power supplies (fully analogue) were short lived but easy to replace with something more decent, it will be more difficult with the encoders.

A drawback of the digital control in this series of power supplies is the slight peeing of radio interference by the power supply itself, specifically its digital part. I'm annoyed by this because you don't buy a linear power supply and then have to deal with interference from the power supply itself. The previous all-analogue version did not have this problem. Perhaps it's just a matter of better shielding and filtering of the digital part of the power supply.

I have an INCO Z-3020 (30V 20A), but it is single channel and weighs 30kg.
It should be purchasable for £300-600.

If, on the other hand, you are looking for something lightweight (7.5kg) and mobile, I can recommend the Elind 32DP8 (although it is difficult to predict when it will be available to buy again):
https://archiwum.allegro.pl/oferta/podwojny-z...acz-laboratoryjny-0-32v-0-8a-i8843814256.html
Of course, its power output is low.
Its low specified output impedances for high frequencies are worth noting.
The voltage setting potentiometers are multi-turn.
Well, and at least there is no fan .

I will join the question , what workshop / garage / laboratory power supply to buy ?
I need it for cars to supply voltage to parts removed from the car : check the bulbs of the lamps , radio , air conditioning panel , meter when playing with eeprom , move the engine of the mechanism of lifting the windows , etc .

I think 30V 5A is enough for most of these applications, at 14V it's 70W at 5A.

You could easily use a Chinese Wanptek DPS3010U or WEP 3010D-III, the price doesn't kill, you don't have to watch out for interference either, there's plenty of it in the car. So such a pulser should be able to handle it.

VaM VampirE wrote:

I think 30V 5A is sufficient for most of these applications, at 14V it's 70W at 5A.

You could calmly use a Chinese Wanptek DPS3010U or WEP 3010D-III, the price doesn't kill, somehow super you don't have to watch out for interference either, there is no lack of it in the car. So such a pulse generator should be able to handle it.

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OK.
And if there is a little more in your pocket for such an investment then a good choice would be for example McVoice LN-303 Pro .
Is it better to buy two separate power supplies ?

dawid1346 wrote:

Factually, the 10A is just in case but as I thought about it, 5A is enough

Personally as a workshop power supply I use the ZHIAOXIN RXN-305D i.e. 0-30V 0-5A, the current limitation works elegantly, coarse and fine regulation of voltage and current also. The power supply is capable of supplying power to devices, and does a great job of short circuit detection (on current limitation).
I'm sure there will be some who will start whining and inventing unbelievable things. You can easily fit it in your budget. For hobby use, this one (I'm sure because I've tested it myself) will do the job and you'll be happy with it.