I've been thinking about it, it would be possible to convert than to monostable operation to do the exact thing he asked for in the first post, i would need to think about it a bit though.

I've been thinking about it, it would be possible to convert than to monostable operation to do the exact thing he asked for in the first post, i would need to think about it a bit though.

i'd suggest ,that to get back to his first idea, that he look at some form of op amp, possibly rectifying the input from a microphone, and passing the output on to a logic gate( CD 4050) TO CONVERT this .One gate could be connected via led/resistor to +ve ,the other via led/resistor to -ve,.

I've been thinking about it, it would be possible to convert than to monostable operation to do the exact thing he asked for in the first post, i would need to think about it a bit though.

Well today I got it working - Thank you two very much.

I'm now interested in the above 'monostable operation' - So, erm mono being 'one' you are saying to use the one current input and covert it from + to - correct? Or have I got that wrong?

no, monostable basically means it has one stable state... For example your green led is on constantly, then when you trigger the circuit it switches to it's other state for as long as the trigger is active which lights up your red led, then it automatically switches back to it's other state once the trigger is released.

it's a question of using a tiny electret microphone and possibly a transistor to act as a trigger to the circuit, and rewiring the 555 chip slightly differently. You would ne able to set the sensitively of the system by altering the values of the resistors, I'm not convinced fully about using an op amp as the dual supply voltages required might just melt your mind at the moment.

no, monostable basically means it has one stable state... For example your green led is on constantly, then when you trigger the circuit it switches to it's other state for as long as the trigger is active which lights up your red led, then it automatically switches back to it's other state once the trigger is released.

it's a question of using a tiny electret microphone and possibly a transistor to act as a trigger to the circuit, and rewiring the 555 chip slightly differently. You would ne able to set the sensitively of the system by altering the values of the resistors, I'm not convinced fully about using an op amp as the dual supply voltages required might just melt your mind at the moment.

Happy to post it to you

Depends if you like a challenge and think you can dumb it down enough for stupid (me) over here?

mONO/ASTABLE with 555- look here

http://en.wikipedia....ki/555_timer_IC

Edited 6 April, 201214 yr by VWD

Was looking through some stuff I' d downloaded anf found this http://clarkson-uk.com/555-timer/program.html.

Works out the values for 555 componants .