Clap Switch Circuit Mod - a short delay, 10ms to 100ms

[robert123456]

Hi

I would appreciate some help on a Clap Switch circuit which I would like to introduce some delay into. At the following address you will find the circuit diagram of the circuit.

https://www.velleman.eu/downloads/0/minikits/manuals/manual_mk139_rev1.pdf

I would like to find a simple way of introducing say a short delay, 10ms to 100ms, between the input of the circuit and the output going high and firing the relay.

If someone could point me in the right direction as to what I need to do, I should then be aqble to customise to my specific circumstances.

Any help would be appreciated. Thanks

 

[IanP]

Re: Clap Switch Circuit Mod

There is a microcontroller in this circuit and the "software" way to go is to add a SUB that introduces a delay ..
The "hardware way" would be to add something like 555-timer [configured as one-shot device] between R12[CLAP] and the PIC's GP3 pin and insert the delay point right there ..

IanP
:|

 

[robert123456]

Re: Clap Switch Circuit Mod

Thanks

I can see how I could use a 555 timer to achieve the end result.

Is there any way that I could introduce some delay around IC1 (Lm324) with just some capacitance and resistance?

 

[IanP]

Re: Clap Switch Circuit Mod

Is there any way that I could introduce some delay around IC1 (Lm324) with just some capacitance and resistance?

Not really, if, for example, you "experiment" a little bit with C10 by increasing its value you'll see that the circuit will stat missing claps ..
IC1-D is a comparator with hysteresis that switches when it detects a clap, so any delay can be introduced after it, not before ..

IanP
:|