#Simple touch timer series#

#Simple touch timer series#

Hammond's 1552 series offers modern style and comfort with accessories that enhance capabilities. Omron's G8PM DC Automotive PCB Relay is a high load automotive relay for motor/resistive control. With enough capacitance this circuit can put up a turn on time of minutes. This turn on time can be increased by connecting a high value capacitor. So once the trigger is given the turn on time of the LED depends on the charging time of the capacitor. Hence the LED turns off at capacitor discharge. So on capacitor discharge the threshold pin goes high resetting the flip-flop which is set HIGH by the trigger pin and so the output also goes low with it. The trick is, the Threshold pin is set up internally to reset the flip-flop. The capacitor, once reaches a voltage level it discharges through the THRESHOLD pin (pin6) of 555. Once the touch is removed the high stage of output merely depends on the charging time of the capacitor connected between pin6 and pin1. However this high stage can’t be retained for long once the trigger is removed. So on touch the trigger pin forces the internal flip-flop to SET mode and so the output goes high. As said earlier since this pin is very sensitive it will pull the 555 output high by touch. When this pin is high the output will be high and when this pin is low the output is low. This trigger pin SETS the flip-flop inside the 555 TIMER. This trigger determines the output of 555. This pin can merely be pulled high by human body potential. The trigger pin in the timer is a high impedance one and is very sensitive. Now the LED will not turn on as the trigger is not given. So with the capacitance change one can get many turn on times and so can make the use of this circuit as a stair case lamp.Īs shown in the below video, the touch switch circuit is connected on the breadboard as per the schematic diagram, and power is turned ON.

This circuit can be modified to turn ON for 2minutes for a single trigger by replacing the 10uF capacitance with a 1000uF one. The capacitor between pin6 and pin1 determines the turn on time of LED once a trigger is passed. The voltage supplied in this circuit must not exceed 6V, doing so will result in IC burn out. The aove figure shows the circuit diagram of touch switch. Once the trigger is removed the LED turns OFF. The LED will be ON for the time during which the trigger is present.

Basically in this circuit we will have a LED which turns ON when we touch a pin of timer. Here the stable stage is LOW, so the timer outputs low after the trigger is removed. This simple Touch Switch is developed by using 555 timer IC operated as a MONOSTABLE vibrator.