Using this circuit diagram can be made a simple connection circuit with touch sensor. This circuit allows delayed disconnection of the connected device, meaning that the circuit will remove power after a set time period.
Using this electronic circuit is possible to switch a device with a maximum consumption of 300 mA.
The main components are the six trig Schmitt contained in an integrated circuit type 4016.
Sensory key consists of two conductive plates which are linked through the skin resistance. When no key is touched, R1 creates a logical "1" on the entry of IC1a. This gate is followed by a diode D1, which not allows charging of C1, just when output of IC1a is logical "1".
Device connected to the output terminals will be powered as soon as key is touched, because capacitor C1 is charged quickly. Capacitor discharge time (and thus feeding the machine) is quite long and depends on the value of R2 and the resistance losses (can be increased by setting a higher value for R2).