> David Schmidt > Anyone have any tips on making an amp-hour meter for a solar power setup? > > I have about 20 amps of charging current going into a bank of 440Ah, 12V > batteries feeding a 500W inverter. > > I have a 200A 50mV shunt that will be used inline with the battery. > > I'm going to take the voltage from the shunt to feed a voltage to frequency > IC, and then count the pulses. There will be two V to F circuits, one for > charge, the other for discharge. The pulses will feed into a '54 driving a > 16x2 line LCD display. > > Anyone see anything wrong with the above plan? > Thanks in advance > Dave Why do you want to use V-F convertor ? Use PIC with ADC! I suppose that 8 bit its enough (to use C71/C74), or use PIC14000 with it "up_to_16_bit". Of course, you can use OP Amp to amplify your 50 mV to 5V ADC input. I reccomend Analog Device's OP291 - Micropower, Single Supply, Rail-to-Rail Input & Output. Alex Torres, Kharkov, Ukraine (exUSSR) altor@chat.ru 2:461/28@FidoNet http://www.geocities.com/SiliconValley/Lab/6311