When the touch delay switch is in use, just touch the touch electrode with your finger, the light will light up and will automatically go out after a delay of several minutes.The two-wire system can directly replace the ordinary switch, without changing the indoor wiring.

Touch Delay Switch Wiring

Touch Delay Switch Circuit Diagram Description IC1 is a piece of 555 timing circuit, which is wired here as a monostable circuit.Normally, because there is no induction voltage at the P terminal of the touch piece, the capacitor C1 is discharged through the 7th pin of the 555, the output of the 3rd pin is low, the relay KS is released, and the lamp does not light up.When the light needs to be turned on, touch the metal piece P with your hand, the human-induced miscellaneous signal voltage is added to the trigger terminal of 555 by C2, so that the output of 555 turns from low to high, the relay KS is sucked, and the light is lit.At the same time, 555 pin 7 is internally cut off, and the power supply then charges C1 through R1, which is the start of timing.When the voltage on capacitor C1 rises to 2/3 of the supply voltage, the 555 pin 7 channel passes to discharge C1, so that the output of pin 3 changes from high to low, the relay is released, the lamp turns off, and the timing ends.The timing length is determined by R1.C1: T1=1.1R1*C1. According to the value indicated in the figure, the timing time is about 4 minutes. D1 can choose 1N4148 or 1N4001.


Principle of

Touch Delay Switch

About the working principle of this switch: touch delay switch has a metal induction piece on the outside, a person touches it to generate a signal to trigger the triode on, charging a capacitor, the capacitor forms a voltage to maintain a field effect tube tube on the light bulb.When the hand is removed, stop charging the capacitor, after a period of time the capacitor is discharged, the gate of the field effect tube becomes a low potential and enters the cutoff state, the bulb goes out.Touch delay switch circuit dashed line on the right is the general lighting circuit, the left part is the electronic switch part. vd1~vd4.VS forms the main circuit of the switch, and IC forms the switch control circuit.Normally, VS is in the off state and the light is not on. vD1~VD4 output 220V pulsating DC current through R5 current limiting, VD5 voltage regulator, C2 filtering output about 12V DC power for IC use.At this time, the LED glows to indicate the switch position, so that it is easy to find the switch at night.

Touch Delay Switch Circuit

Touch delay switch circuit dashed line on the right is the general lighting circuit, the left part is the electronic switch part. vd1 to vd4.VS forms the main circuit of the switch, and IC forms the switch control circuit.Normally, VS is in the off state and the light is not on. vd1 to vd4 output 220V pulsating dc through r5 current limiting, vd5 voltage regulator, c2 filter output about 12v dc for IC use.IC is a double D flip-flop, only one of the D flip-flop will be connected to a monostable circuit, steady state 1 pin output low level, VS off.When the human hand touches the electrode M, the human body leakage current is divided by R1.R2, and its positive half-cycle makes the monostable circuit flip, 1 pin output high level, added to the gate of VS by R4, so that VS opens and the lamp lights up.At this time 1 pin output high level by R3 to capacitor C1 charging, so that 4 pin level gradually rise until the end of the transient state, the circuit flip back to the steady state, 1 pin sudden change to low level, VS lost trigger voltage, AC power over zero that is turned off, the lamp off.