Recommend an inexpensive Bench Power Supply?

[jefe]

Can anyone recommend an inexpensive benchtop power supply? I really only need 9 & 12 VDC, maybe 2 amp?

Any opinions on this one? I like the price ($20):
http://www.circuitspecialists.com/prod.itml/icOid/8238

Also, I've got a big 18V wall wart at home. Could I just somehow step that down to 9 & 12 volts and consider that "good enough for now"? (i.e. until I need something better?)

Any advice would be appreciated.

[mojo_hand]

Sounds like your wallwart, an LM317, a small heatsink, and an adjustment pot would do.

[Ronsonic]

Can anyone recommend an inexpensive benchtop power supply? I really only need 9 & 12 VDC, maybe 2 amp?

Any opinions on this one? I like the price ($20):
http://www.circuitspecialists.com/prod.itml/icOid/8238

Also, I've got a big 18V wall wart at home. Could I just somehow step that down to 9 & 12 volts and consider that "good enough for now"? (i.e. until I need something better?)

Any advice would be appreciated.

That looks like it should work for you. If you take a look at the datasheet for the LM78XX series of regulators, 7809, 7812 and like that, you'll see some really simple examples of how to get the voltage you want. Basically, if you run the positive from your supply to the input pin, connect the negative to the reference pin, you'll have the indicated voltage between the negative and the the output pin of the regulator. Stick a small cap across that (1uF or so) and you will have built a supply and learned something new.

Ron

[Seljer]

Sounds like your wallwart, an LM317, a small heatsink, and an adjustment pot would do.

and add one of these to make it all pretty
http://futurlec.com/Panel_Meters.shtml

[jefe]

Thanks guys - these are some good ideas. Took a quick look at the datasheets for LM317 & 7809, and either way looks very straightforward. And yeah, I was already thinking panel meter, lol.

I'm just curious, what do you guys use as a bench supply? Wall wart? Just use a battery? More expensive power supply?

[petemoore]

 0-200mV Full Scale Input Range
  that's 200 millivolts

[jefe]

0-200mV Full Scale Input Range
  that's 200 millivolts

There are some alalog gages further down the page that have a range of 0-5v, 0-10, 0-15, etc. I like analog.