View Full Version : What is a switching power supply?

11-13-2005, 05:52 AM
Can someone tell me what the difference is with a switching power supply?

From what I have gathered from the archives, switching power supplies are lighter but have less constant or "clean" power. Is that correct? Would the more variable power cause any problems using it as a power supply for LiPo or NIMH chargers?

Here are a couple that I have seen. Anybody have experience with these? I would appreciate any feedback...

20A Switched RC specific http://www.hobbypeople.net/gallery/158301.asp (http://www.hobbypeople.net/gallery/158301.asp)
20 A Switched General http://www.millionbuy.com/pyrpsv200.html (http://www.millionbuy.com/pyrpsv200.html)

7A Switched http://www2.towerhobbies.com/cgi-bi...p?&I=LXUF47&P=7 (http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXUF47&P=7)

10 A General http://www.millionbuy.com/pyrps15k.html (http://www.millionbuy.com/pyrps15k.html)

Thanks in advance,


Matt Kirsch
11-13-2005, 04:31 PM
There are two different types of power supplies, transformer and switching.

A transformer power supply uses a simple voltage transformer to get the voltage close to the target. This is the heavy piece in the supply, and what makes them more expensive.

A switching power supply works on a principle similar to that of your airplane's ESC. The power is switched on and off many thousands of times per second to simulate a lower voltage.

Both types of power supplies use a voltage regulator to produce the final voltage. The regulator absorbs all the "spikes" and fills in the "low spots."

Neither type produces perfectly "clean" power without the regulator, though I would imagine the transformer type would be considered the cleaner source because it's producing a constant voltage, not a series of source-voltage spikes separated by a bunch of rest periods. Still, the switching type power supplies, with the regulator, is perfectly fine for general use and a good value.

11-13-2005, 07:06 PM
I have two of the 25 amp radio shack switching power supplys to run my chargers, they work great so far.

11-14-2005, 03:55 AM
Thanks for the good info and clear explanation. I'll probably go with one of the switching power supplies.