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Basic Toggle Switch Circuit

AnalogKid

Jun 10, 2015
2,884
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Jun 10, 2015
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2,884
1. Yes.
2. That's what I get for using someone else's library. Corrected files attached.
3. No. System 5V comes in from the USB connection, and is decoupled by D1 and filtered and stored by C1. +5V powers the 4093 and the turn-on pulse former C2/R1. When the USB 5V goes away at turnoff, U1A inputs go low and drive the turnoff pulse former C3/R3. This works because even though the 5V input is gone, C1 holds enough energy to run the circuit for 1 second, long enough to make a 1/2 second output pulse.

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SpeakerToggle-1-ch.gif
 

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  • SpeakerToggle-1-c.pdf
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AnalogKid

Jun 10, 2015
2,884
Joined
Jun 10, 2015
Messages
2,884
Second pass. This one has a single monostable for consistent output pulses rather than two edge stretchers, and a larger holdup capacitor to assure the turnoff pulse. Note that none of the component values or tolerances are critical.

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SpeakerToggle-2-ch.gif
 

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  • SpeakerToggle-2-c.pdf
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