Re: compound variable power supplies--possible?

You can connect two DC adapters in series (not paralle), plus of one to negative of the other; then add the two voltages together. In your example, a 6V and 3V will yield 9V If one is turned off, you will not warp the universe.

whyzard@xxxxxxxx wrote:
Sam Goldwasser wrote:
whyzard@xxxxxxxx writes:

Can i take two wallwart power supplies (the AC to DC variety) and just
tie them together in series and parallel to make a cheap diy variable
powersupply.

I am thinking of getting a cheap variable DC 12V ($20 at Fry's), and
then adding a universal DC adapter with up to 12 v also. So if i wire
these in series or parallel or whatever, can i say add 3 v DC to 6 v Dc
to get a usable 9v DC? Or is there gonna be some law of electronics
broken?
If they are in series and both on, then it may work within their current
ratings.

But think about what happens if one of them is not powered on.





would primary coil windings get blown open if the second unit was off?
Would any power surge happen to the total output? I wouldn't want to
blow the device powered off my budget diy supply. I know i can make one
diy for the same money, but i am too lazy and the variable at fry's had
something like 2 or 3 amps which i need.

i don't want to buy a real variable now cause i don't know anything
about electronics yet and i don't know what is a good investment for my
needs.

is there any ripple off AC adapters? Do i have to worry about compound
inductance, reactance, stuff like that which i don't know anything
about. Now i am scaring myself. I guess i would have to research this
myself. I suppose that I could use as a reference two batteries tied in
parrallel or series, then compare the waveforms to the compound
adapters. Shouldn't take too long.

I hope this never blows up my guitar effects boxes!





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