One of the application circuits we gave with the 4013 in this circuit bank was a bistable switch in which the 555 was used as monostable to drive a 4013. Well, if we're just going to use a flip flop to drive a relay, the other It can perfectly be used as monostable, as shown in the figure configuration that works as an excellent touch key. In this switch, at each touch of the sensor, the relay changes state, thus switching an external load.
