Benchtop power supply

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Hi, I am looking for an inexpensive benchtop DC powersupply and have come across this:
Minleaf DC60V 300W Adjustable Power Supply Precision Variable Digital Lab Test

I am a newbie to makering. Does anyone have experience with this product or can recommend a more apopropriate one?

Thanks for any help

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Hi Peter

Depends on what your priorities are. Are you going to need voltages as high as 60V ? If you are going to work with the usual hobby things you probably won’t get to need much more than 12 or 24V. There seems to be a lot of activity with high power LEDs and a lot of them. It won’t take many of these to use up the 5A of this supply and still only use a maximum of 12V.
With this in mind maybe the better option would be to go for more current. I notice there are a selection of 30V 10A units around in a similar price range but at the end of the day it is up to you. You are the only one that knows what you are going to need.

Tip: DON"T buy anything WITHOUT current limiting facility. Down the track with more experience you will find this feature very useful and you will miss it if it is not there.
Cheers Bob

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Hey Bob, thanks for your thoughts mate. I will have a broader look then, taking your advice into consideration.
Cheers
Peter

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I’m with Bob on this - while it looks like good specs, there’s not much point buying something that can do 60v if you’ll never use it, and you lose resolution at three lower end.

I’ve got a little 30v 10A myself and it does me for pretty much everything. 30v will do everything from microcontrollers right through to 24v truck electrical systems. If you’re very careful you can even establish a floating ground for a +- 15v setup from a single channel.

Programmable supplies are nice top have but you can definitely get by without that feature.

And most switch mode supplies are quite low noise these days. Which is probably the most important specification to look at - your supply noise. 50mV (ie. 0.05v) RMS at full load would be about the max I’d go for.

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Hey [just some guy named] Oliver,

Thanks for your input mate. Like I said, I am new to this but want to make the right decisions along the way. It is great now to have more information to research with.

Cheers
Peter

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No worries! Glad to help out :slight_smile:

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Hey Bob, Oliver,

Is “current limiting” the same as “current stabilization”? I am finding “stabilization” in product descriptions rather than “limiting”.

Cheers
Peter

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Hmm, maybe - do you have an example?

The first few minutes of this video give a good explainer of current and voltage limiting modes:

Edit: One key point, I’d recommend following a different procedure to set the limits:

  1. Set all knobs to 0 (Note that this will usually trigger CC mode)
  2. Short the leads
  3. Set the current limit - CAUTION! Your test leads will get hot quickly! Set the current limit quickly and then disconnect the leads ASAP.
  4. Set the voltage limit.

Just note that for step 3, you might need to bump the voltage limit up slightly with the fine knob to provide enough voltage to generate enough current.

Some fancier supplies have a review button so you can just check your settings without needing to go through this rigmarole.

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Oliver, I have found this unit mate:

10A 30V DC Power Supply Precision Variable Digital … https://ebay.us/I19uUG

The description includes:

  • Voltage stabilization: ≤0.05% +1mV
  • Current stabilization: ≤0.1% +10mA
  • Load stabilization: CV≤0.1% +1mV / CC≤0.1% +10mA
  • Ripples and noises: CV≤10mV(RMS) / CC≤20mA(RMS)
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Ahh ok. These specifications are to do with how that supply responds to sudden changes in load on it, and the supply voltage from the wall eg. when you bump your wires together and short circuit it, the power supply suddenly goes from 0A to your set current limit. These values are to do with how far it overshoots your settings while it’s stabilizing, and how close it gets to your set values.

The noise and ripple are present all the time - even at steady state.

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Ahh ok Oliver, that makes sense then.
So not really current limiting then. I might look further.

Great video by the way. Thanks…

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Hi Peter
Just checked that link. Noted the following statement
" * Constant Voltage & Constant Current Mode - Features rotary knobs for adjusting the value of output voltage and current finely or coarsely, meeting different test requirement".
This will be current limiting. Generally if a unit has coarse and fine current adjustment controls it will be current limiting. so this unit will fit the bill. The “CV” means constant voltage and “CC” means constant current.

Constant voltage is self explanatory but research the use of constant current. For instance if you switch on with CC at minimum you will not get any voltage. This has fooled many into thinking they had a faulty supply. This would normally be set at near maximum until you have a specific reason to want to limit the supplied current. In this case when you attempt to exceed the set current limit you will find the current remains constant but the voltage will fall. This is quite normal.
Cheers Bob
The “stabilisation” referred to is as Oliver explained.

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Hey Robert, thanks for following up with this mate.

And yes I am familiar with Ohms Law and the relationship between voltage and current (and resistance), though I still need to refer to the card :slight_smile:

Thank you both (++ Oliver) for your help with this.
Cheers
Peter

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Hey Peter,

No worries :slight_smile: Yep, like Bob said, that one you linked does have current limiting - that’s the constant current (CC) mode.

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Hi Peter
Who mentioned Ohm’s law. Very important and good that you are familiar with it.

Study that video. It demonstrates in video form what I tried to explain above. Will stop you falling into explainable traps…
Cheers Bob

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@Bob :+1:

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@Oliver :+1: