23 Sep
2011
23 Sep
'11
1:07 p.m.
It's been quite a while since I've had to troubleshoot a powersupply and I
have one that is making a loud whine and need to put a load on it to make
sure it is functioning properly. Any suggestions? It is 12V/24V switchable
output.
Most cars (at least over here) have 12V electrical systems nad use
filament lamps of various powers....
A stop lamp bulb (12V 21W) is good for about 2A of load (a bit under), a
5W sidelamp bulb is just under an half an amp, a haeadlight bulb (55W
normally) is 4-5A, and so on. They;'re fairly cheap and easy to find.
For 24V, either use 2 identical 12V bulbs in series (but note they may
well not share the votlage evenly.) or use 24V lorry bulbs.
6V bulbs (old cares, motorbikes, etc) are good for loads on 5V supplies, BTW.
FInding holders for some of these bulbs can be non-trivial. Either solder
wires driectly to the lamp contacts, or get some old car light units from
a scrapyard.
-tony