The relay is a 12 V DC relay operating at currents less than 200 mA. Advertisement. 555 Touch Sensor Switch Schematic. Advertisement. ... 28 comments on “ Touch Sensor Switch Circuit with 555 timer ” ...

Please note that, here T1 is wired as a mini electronic timer. Even after the PIR relay switched off, output relay (RLY1) remains in on state for a short duration decided by the value of timing ...