Em 5/2/2010 15:56, Marc Nicholas escreveu: > All this talk of cheap UPSes is timely... > > I'd like to be able to provide a few seconds of +5vdc to a device so that > when its main power line fails it gets to "finish what its doing" (which = it > will if it is no longer being fed data, but needs a second or two to do s= o). > > Super or ultra caps come to mind, but I've never worked with them and some > casual Googling hasn't turned up too much of interest. > > Any suggestions on where to start or tips? Obviously I don't want to end = up > with blown caps and/or blown device! > > TIA. > > -marc > > P.S: Oh, power draw for the device is 150mA nominal....so hoping I can ju= st > do something with a Schottky, resistors and cap! > = > This cap: is rated at 120000uF x 16V and costs just $12.50 @ unit. Charge it to 10V, use a buck regulator and it will last over 4s before the voltage drops to 5V, more if you charge it closer to its rated voltage. Regards, Isaac __________________________________________________ Fa=E7a liga=E7=F5es para outros computadores com o novo Yahoo! Messenger = http://br.beta.messenger.yahoo.com/ = -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist