On Thu, 5 Mar 1998 18:02:02 -0500 Mike DeMetz writes: >Anyone using super caps (.3-1F) for clock or memory back-up? If so do >you have a problem with inrush current if you let it discharge too >far? These capacitors have an internal resistance on the order of 100 ohms. Often this is enough to limit the inrush current. If not, just connect a resistor in series with the capacitor. Since the discharging current is very low, the resistor won't cause a significant voltage drop. Also they have a leakage current. Regardless of the capacitance, even with no load connected, they tend to discharge by themselves after a week or so. If your application needs to run from the backup for longer, then a battery is the only choice. "Discharging too far" is not a problem, unless discharged past zero, i.e. charged in reverse. _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866]