GB1345651A - Electronic control apparatus - Google Patents

Abstract

1345651 Control of DC motors H MIZOULE 12 May 1972 22349/72 Heading H2J [Also in Divisions G1 and A6] A control circuit for a device such as a D.C. motor is operated in response to the displacement of an electrostatic charge in the vicinity of a pick-up A. In the arrangement of Fig. 2 the supply circuit of motor M is controlled by a bi-stable circuit of SCRs T3 and T4. Normally FET T2 is conducting and the potential on the gates of SCRs T2, T4 is such that they are non- conducting and the motor M is not energized. If an electrostatically charged rod is now placed adjacent pickup A the displacement of the charge thereon switches off the FET T2 so that the rise in potential at the anode switches on SCR T4. The supply circuit is thus connected to the motor M. If the charged rod is again brought up to the pick-up A a second time SCR T3 is rendered conducting and SCR T4 is blocked by the discharge of capacitor C2 so that the supply of current to motor M is open-circuited. Instead of using a bistable arrangement only one SCR may be used, Fig. 1 (not shown), in which case a switch operated by the motor after a predetermined time is utilized to shortout the SCR and subsequently disconnect the motor from the supply. The motor may be incorporated in a toy vehicle, animal or doll, see Division A6, and if these are made of plush or like synthetic material the FET may be operated by movement of the hand instead of the rod.