how to generate -5volts from +5 volts

[mishra12]

hi
i know how to make -5volts from +5 volts using 555,ICL7660 so is there any simple way to generate -5volts from +5 volts my input voltage is 7.5 volts dc and i am using lm 7805 regulator for 5 volts supply now i need -5volts .
santo

 

[Tahmid]

Hi,
I didn't get what you want? Isn't using an ICL7660 simple enough?

 

[mishra12]

i don't want to use chip but using zener capacitors will do

 

[Tahmid]

Chip would be simpler. However, you could use a transistor based multivibrator, then diode, capacitor at output, similar to 555 design, but without "chip" as you put it. Pretty simple, but 7660 is simpler, imo.

Hope this helps.
Tahmid.

 

[mishra12]

i am designing the circuit when finished i will post here