Need advice - Which laboratory power supply to buy?

[scokljat]

Hello,

I'm about to buy 2 x 0-30V 5A lab power supply.

After tour around local tech shops I narrowed selection on two models:


Matrix MPS-3005LK-3 (222$)

http://www.szmatrix.com/en/product_show.asp?id=103

or

McPower DIGI 302-05 (252$)

http://www.zeitech.de/McPower-Digi-3...Anzeige-30V-5A


Matrix looks better, has big alu heat sink + two fans, voltage can be adjusted very fine because knob make 3 full circles from 0-30V, it's 30$ cheaper than Mc Power. Manufacturer (Matrix) has good webpage and company produce professional lab equipment.

Mc Power does not have visible alu heat sink, it has two fans which spin variable as unit heats up. At start it makes it more silent than Matrix (fixed fan speed) but I didn't test it under load to check how silent fans are when unit heats up. Manufacturer (McPower) looks generic - no name. Didn't find official webpage, unit is mentioned only on webshops.

Both units have an extra 5V/3A fixed channel.

Currently, model from Matrix looks more solid to me.

Which one should I buy? Take a look at attached pics and specs. Any suggestion is more than welcome...

Thanks,

Best regards,

Suad

[stj]

Re: Need advice - Which laboratory power supply to buy?

or this one.
http://www.rigol.com/prodserv/238/

[redwire]

Re: Need advice - Which laboratory power supply to buy?

Both of them look like vanilla linear PSU's from China. The Matrix looks better constructed, like GW Instek. They can be touchy to dial in an exact voltage or current.
Newer bench PSU's like the Rigol use switching power supplies and have neat features like programmable pulse outputs, high res panel meter, keypad, LAN and USB etc.
It depends what kind of work you are doing. I really hate noisy fans running all the time so I have big, heavy and silent linear power supplies on my bench.

[stj]

Re: Need advice - Which laboratory power supply to buy?

the Rigol actually uses a Linear regulator and a big toroid transformer.
there is a teardown video at EEVblog
https://www.youtube.com/watch?v=s4rV20ulsm0

[redwire]

Re: Need advice - Which laboratory power supply to buy?

The Rigol DP832 is selling for $450-500 USD, and I had to chuckle because the teardown shows no protection diodes, and Dave at EEVblog found a transistor running at 90°C and overvoltage spike during power up, in 2013.
http://www.eevblog.com/2013/08/30/ee...investigation/ Rigol has since fixed the bugs.

I don't mind analog linear PSU's...