change 9V to 4V ps of circuit

iONic

Joined Nov 16, 2007
1,662
I'm not sure the 555 will run with only 4V, 4.5V is the minimum I believe. Possible changing the speaker from 8 ohms to 4 ohms might help the output volume level, but you will still have to power the 555. Exactly what sort of power source are you using that you only have 4.0V?

You could take a look at two other 555 alternatives:
ZSCT1555

or

The EXAR XR-L555

Not sure if either of these are available anymore.
 
Last edited:

Thread Starter

simf14

Joined Jul 27, 2007
43
Thank you for your help...its really appreciated. Nothing is really ever easy is it? Trying to use the circuit for what it was not intended for. I will add an opticoupler or something. Thanks again.
 
Top