Electronic load considerations / PSU testing

[Alex]

Hi all,

I need to test a variety of power supply circuits at home and I am considering purchasing a bench-size programmable electronic load. Typical power supplies might exceed 300VDC at a few mA. On the other hand some low voltage supplies are in the 1.8-48VDC range at a few amps. Overall, I dont have an immediate need for anything above 150W. I will be needing a constant power and constant current modes, with constant resistance being useful (depending on response time).

There are a few China-made candidates on ebay and rebrands of those. However, keeping all options open, what other specifications would you be looking at when searching for an electronic load? I wont be doing any testing of PV panels, so I cant see the minimum input voltage as a function of current being a high priority factor. Budget is about $500.

Any input/ideas much appreciated.

[DaveW]

It won't do anywhere near your HV side, but this,

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1799872

will do up to 60V, 150W. I have one of these at work, the user interface takes a little getting used to as it's shoehorned into a PSU enclosure, but it works well. It also has a very good step response which can be an issue if you look at turn on characteristics, especially of switch modes. With a 10ms pulsed load (external FET switching load into circuit, at 0.9 ohms load, 5V supply) this one responds in less than 0.2ms.

Other than that, some of the cheaper ones are exceedingly loud, and I have heard of some that have a rather high TC-never come across one myself though