Re: Please suggest a time delay toggle switch


<mingyan_chow@xxxxxxxxxxxx> wrote in message
news:1125914697.068569.21260@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>I need a CMOS 4XXX toggle switch it's flip flop output is either high
> or low while powered on doesn't matter. But if you press the buttom for
> 5 seconds, it automatically change state and retains at that state even
> when you release the buttom until you powered off. Please suggest ,
> Thanks.
>
Get a 74HC74, a 74HC14, and a SPDT switch.
Connect 2 sections of the 14 in series.
Connect the output of the second stage to clock of the 74.
Connect a 100 uF capacitor from input of the first 14 to ground. Connect the
common terminal of the switch to the same.
Connect a 560K resistor from the NO terminal of the switch to VCC.
Connect a 100 Ohm resistor from the NC terminal of the switch to ground.

Tam


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