help with simple UPS 12v

Discussion in 'The Projects Forum' started by greenearth73, Mar 6, 2013.

  1. greenearth73

    Thread Starter New Member

    Mar 6, 2013
    dear sirs,

    i have little knowledge in electronics but i in need for a simple ups 12v something like that :

    its simple UPS (+9V , +12v) load 1.5A max.

    power on , charge battry , +12v,+9v on
    power off , battry feed for 7 min , 12v,9v on
    after 7 min , ups is off

    i need values for Q,C,R1,R2
    if you got a better i will be very thankfull