I need someway to stop my 555 timer from outputting a pulse with the use of a switch. Are there any two pins I can hook up which would stop it?

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    \$\begingroup\$ Do you understand what the RESET pin does? \$\endgroup\$
    – Dave Tweed
    Jan 2 at 18:04
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    \$\begingroup\$ It depends how you want to stop it and in which configuration the 555 is currently connected to produce the outpuy. But withouy those details, the answer what you want cannot be given in detail, we can only guess how your circuit now is and how you want the signal to be stopped. Please add the details. \$\endgroup\$
    – Justme
    Jan 2 at 18:18
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    \$\begingroup\$ Will you want to stop all future pulses too? If not, will you want future pulses to follow on in the expected sequence after the missed one, or to restart the timings from scratch? \$\endgroup\$
    – gidds
    Jan 3 at 21:24

3 Answers 3

  1. Connect a SPST switch between the Reset pin (4) and GND (1).

  2. Connect a 10 K resistor between the Reset pin and Vcc (8).

Closing the switch grounds the Reset input, which terminates all device functions.


The easiest solution is to put a normally-closed pushbutton switch between the 555 output and the device receiving the pulses. If the downstream device can't be left floating, use a pull-up or pull-down resistor.


simulate this circuit – Schematic created using CircuitLab

(timing and power connections not shown)


A button between GND and RESET (assuming it already has a pull-up) will do exactly that.


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