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Latching ON/OFF Circuit with Single-Wire Remote Control & Indication from Multiple Push-Buttons

Momentary PB controls remote bistable circuit with PB LED status using a single wire.

  1. PB Latching High Side Switch with LED Indicator

    Below is a modification to the original circuit which uses a high-side MOSFET switch instead of a relay to switch the load.

    PB High Switch Switch.PNG
  2. Momentary PB to Gnd controls remote bistable relay circuit with PB LED status using a single wire.

    Here's a modification to the circuit that allows the remote control and indication of a latching relay circuit using a single wire with the PB connection to ground, thus requiring no power or added circuitry at the PB.
    It requires one 4013 flip-flop package and two transistors.

    Below is the LTspice simulation of the circuit:


    When the relay is ON, current flows through D2 and R7 to light the LED indicator at the PB. This voltage also saturates Q1 so the...
    Gasboss775 likes this.