Connecting monostable 555 to astable 555

[marbling]

I am currently connecting a circuit where I power the astable 555 via the monostable 555, but my astable seems to be giving a constant 3.5V even when the monostable is not activate. It works on multisim but doesnt work wheni connect it Can someone help? Thank you!

 

[schmitt trigger]

If you are attempting to make a gated burst oscillator, which will drive your counters downstream, I would do *independent of each other* astable and monostable circuits, and combine their outputs with an AND gate.

 

[crutschow]

Sounds like a wiring error.
If the trigger input is held low, the output will remain high.
Double check all the connections against the schematic.

 

[Les Jones]

Have you tried connecting the top of R2 directy to +5 volts ? If it is a standard 555 (Not the CMOS version ) a 5 volt supply is close to it's minimum voltage rating of 4.5 volts it may not work at your designed operating frequency (48 Khz.)

Les.

 

[alec_t]

Have you tried driving the Reset pin of the astable for switching it on/off?

 

[marbling]

If you are attempting to make a gated burst oscillator, which will drive your counters downstream, I would do *independent of each other* astable and monostable circuits, and combine their outputs with an AND gate.

Thank you! It finally worked.
Thank you everyone for your suggestions too!

 

[Les Jones]

But WHAT was the fix ?

Les.