What do you think about these very inexpensive benchtop power supplies?

[Jay112]

Thanks everyone for the excellent information and advice! This forum is really exceptional! And thanks for the ebay links!

I'll probably wait a few days to let all this sink in, before purchasing anything. I'll also keep an eye on ebay deals.

[rdl]

Here is a link to the only review I found on youtube. At least you can get some idea of what this power supply is like. Though as usual with low cost electronics from Asia, it would be a good idea to check it for serious problems before use.

While a used HP or similar is better in many ways, something like this can still be useful. It's small, quiet, very low cost, and maybe good enough. It depends on what you actually need.

[ez24]

I think he refers to the uncannily low output noise of some power designs units. Some have like 100 µVpp over a dozen MHz and were built in the beginning 60s. It's like - how did they even measure that back then?!

Aliens have different test instruments than humans do.  This is why PD disappeared from written history (only aliens have the power to make history disappear). 
My guess is they used their PDs to make ships to return home and they left.   My PDs will be worth a fortune if this is ever proven.  Can DNA be found inside power supplies? 

[JoeB83]

At least you know HP were made by humans.  Since there is no known history of PD, I would not bet they were made by humans.

What? 

I think he refers to the uncannily low output noise of some power designs units. Some have like 100 µVpp over a dozen MHz and were built in the beginning 60s. It's like - how did they even measure that back then?!

I see what was meant now, thank you! 

[karoru]

Here is a link to the only review I found on youtube. At least you can get some idea of what this power supply is like. Though as usual with low cost electronics from Asia, it would be a good idea to check it for serious problems before use.

While a used HP or similar is better in many ways, something like this can still be useful. It's small, quiet, very low cost, and maybe good enough. It depends on what you actually need.

It spikes  the voltage and then cuts out on overcurrent? Seriously? Even my USSR-made el cheapo 15V, 1A lab power supply made in 80s without a single IC inside (not even an opamp) will work as constant current when it's set to too big voltage.

[Jay112]

I ended up buying the $27 unit, and also I was the highest bidder for a new B3603 so I got one for $8 ($7 shipping, $1 bid). I'll probably play around a little with these before deciding if I need something better.

Thanks everyone for your replies and suggestions!

[mtdoc]

I ended up buying the $27 unit, and also I was the highest bidder for a new B3603 so I got one for $8 ($7 shipping, $1 bid). I'll probably play around a little with these before deciding if I need something better.

Thanks everyone for your replies and suggestions!

That's a nice low budget combination. I bet it will last you longer than you expect - that is unless you catch the vintage power supply collection bug that infects some of us...

Julien Ilett has on the b3603.

[Jay112]

That was an awesome video review! Thanks for sharing!

[nbritton]

http://www.aliexpress.com/item/DP30V3A-Constant-Voltage-and-Current-Step-down-Programmable-Power-Supply-Module-Buck-Voltage-Converter-LCD-Display/32254182789.html

[nbritton]

That was an awesome video review! Thanks for sharing!

http://www.aliexpress.com/item/B3603-Precision-CNC-DC-DC-Constant-Voltage-Constant-Current-Buck-LED-Driver-Module-Solar-Charging-Power/1625052409.html

With an Arduino I'm thinking you could easily mod three of these boards together to make a triple output power supply.

[AlessandroAU]

Here is a link to the only review I found on youtube. At least you can get some idea of what this power supply is like. Though as usual with low cost electronics from Asia, it would be a good idea to check it for serious problems before use.

While a used HP or similar is better in many ways, something like this can still be useful. It's small, quiet, very low cost, and maybe good enough. It depends on what you actually need.

That's actually my video.
I still have and use the power supply, its pretty lacklustre, but for the price I paid I can't complain. Sometimes you just want to power up a led strip or a PC fan independently.
It can't handle much current, that being said I run to to where the transistor on the back could boil water and it still hasn't died.

[jpasqua]

I've tried both of the small units pictured above (or variants thereof). As it turns out, the Minghe B3603 (the one reviewed by Julien Ilett) happens to fit perfectly into a display case for a hockey puck. Sounds weird, but I happened to notice these boxes while looking for something else. I just drilled a couple of holes to access the control buttons, added binding posts, and a barrel connector for power in.

For the DP20V2A (variant of the DP30V3A pictured above), I was able to add binding posts directly to the case and I ran wires out the back for power in via a barrel connector.

Neither of these units have great user interfaces, but both have worked well so far for undemanding tasks.

[nbritton]

I've tried both of the small units pictured above (or variants thereof). As it turns out, the Minghe B3603 (the one reviewed by Julien Ilett) happens to fit perfectly into a display case for a hockey puck. Sounds weird, but I happened to notice these boxes while looking for something else. I just drilled a couple of holes to access the control buttons, added binding posts, and a barrel connector for power in.

For the DP20V2A (variant of the DP30V3A pictured above), I was able to add binding posts directly to the case and I ran wires out the back for power in via a barrel connector.

Neither of these units have great user interfaces, but both have worked well so far for undemanding tasks.

Which one do you like better? The DP30V3A is over double the price of the B3603, is it worth the extra cost? I was thinking of buying three B3603 and modding them into one triple channel PSU with the help of an Arduino. What buck converter chip is used in the DP30V3A?

[nowlan]

doesnt that ebay switcher have a really long/slow ramp to set point?

[jpasqua]

I've tried both of the small units pictured above (or variants thereof). As it turns out, the Minghe B3603 (the one reviewed by Julien Ilett) happens to fit perfectly into a display case for a hockey puck. Sounds weird, but I happened to notice these boxes while looking for something else. I just drilled a couple of holes to access the control buttons, added binding posts, and a barrel connector for power in.

For the DP20V2A (variant of the DP30V3A pictured above), I was able to add binding posts directly to the case and I ran wires out the back for power in via a barrel connector.

Neither of these units have great user interfaces, but both have worked well so far for undemanding tasks.

Which one do you like better? The DP30V3A is over double the price of the B3603, is it worth the extra cost? I was thinking of buying three B3603 and modding them into one triple channel PSU with the help of an Arduino. What buck converter chip is used in the DP30V3A?

For my use case a couple of B3603's are a better value than a single DP30V3A. I don't have my DP20V2A apart at the moment so I can't tell you what chip it uses.

If you are looking for something you to mod, please check out this github repo: https://github.com/baruch/b3603. A ton of work has been done to reverse engineer the B3603. There is also work on alternative firmware.