The simpler design take this load into account - the charger simply charges at a greater rate than teh discharge of the resistors. They also tout it as a safety feature - the discharge rate is pretty quick once the device is turned off. More advanced solutions conserve that energy by only load balancing when needed. It's not unlike choosing between a linear regulator and a switching power supply - one is dead simple but has higher losses, and the other is slightly more complex and expensive with fewer losses. -Adam On Thu, Aug 27, 2009 at 5:32 PM, Ben Hencke wrote: > Anyone have a schematic? I'm trying to visualize how that would > balance voltage without draining the caps at the same time. I've been > wanting to do something like this with cheap 2.5v super caps for > higher (not hundreds) voltage solar applications. > > Cheers, > =A0Ben > > On Sun, Aug 16, 2009 at 8:50 AM, Spehro Pefhany wrote: >> At 10:19 PM 8/15/2009, you wrote: >>>Since I have 200V caps laying around from scrapped AT computer power >>>supplies , I thought of stacking 5 of them and balancing the voltage >>>with high value resistors and 200V zeners. =A0Is there a better way ? >> >> You'd need 25 capacitors (5 in parallel =3D 1000uF/200V) and then 5 of >> those sets in series to get 200uF/1kV. Resistors are the easiest way. >> If you have 5 200V zeners in series you'll get a lot of current flow >> if the voltage exceeds 1kV by a bit, whereas the caps have some ability >> to handle surges. >> >> Don't kill or maim (eg. blind) yourself, those voltages and energy stora= ge >> amounts (100J) should be taken very, very seriously as they are potentia= lly >> (so to speak) lethal. >> >>>Best regards, >> >> Spehro Pefhany --"it's the network..." =A0 =A0 =A0 =A0 =A0 =A0"The Journ= ey is the reward" >> speff@interlog.com =A0 =A0 =A0 =A0 =A0 =A0 Info for manufacturers: http:= //www.trexon.com >> Embedded software/hardware/analog =A0Info for designers: =A0http://www.s= peff.com >> >> >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist