I'm building a voltmeter based on the ADC and seven segment display driver chip CL7107.. However it needs a dual supply of +/-5v.. What is the simplest possible way to make a negative strip from a positive one?? Also if I use a transisor inverter will it affect its working as this chip depends on the symmetrical pulse of supply.. The data sheet also specifies an easy way of using cd4009 and 2 IN914 diodes and 2 caps.. can i use a 1n4001 diode instead??

 

You might get away with using 1N4001 diodes, but they're very slow compared to 1N914/1N4148 switching diodes.

If you happen to have some Shottky diodes around (like 1N5817, BAT54, etc) those would be a better bet.

 

Hmm. Thanks,... I intend to integrate this circuit inside a bench power supply. So can I use a seperate bridge for powering this circuit from the supply's main center tap transformer and achieve a dual supply?? This chip has 2 seperate input terminals for testing probes.. so i guess it wont short.. Otherwise using 7805 and 7905 with common virtual ground be better??