GB1211998A - Circuit arrangement for the electronic control of actuating members for machine controls - Google Patents

Abstract

1,211,998. Recoding circuits. KRAUSS-MAFFEI A.G. 12 Aug., 1969 [14 Aug., 1968], No.40306/69. Heading G4H. A switching arrangement for control elements which initiate or terminate operation steps of a machine, the elements 18, 19 &c. are controlled by actuating transistor units 15 which are in turn controlled by combinations of switches 6 acting through transistor amplifiers 11 and the electrical connections between the switches and the transistor amplifiers and between the amplifiers and the transistor units 15, and the transistor units themselves are supported on a single plate. The connections between the switches 6 and the transistor amplifiers 11 comprise vertical and horizontal leads printed on opposite sides of the board. Resistors connecting row and column leads are soldered to the leads through holes in the plate. The amplifiers 11 are assembled in groups of four, one for each row lead 4. Resistor connections 13 are made from the row leads 4 in a second conversion matrix 2 to appropriate column leads 5 to actuate selected ones of four bi-stable multivibrators 12. The outputs of these are connected in a third conversion matrix 3, together with some of the column leads 5 of matrix 2, to energize certain inputs to transistor units 15 and thereby operate corresponding power transistors 16 connected by wires 17 to the control elements 18, 19. The transistor units 15 each comprise two similar transistor stages 36, 36a, Fig. 3, providing a signal large enough to control a power transistor 16. The switch 33 is turned on by a signal on lead 5b and off by a signal on lead 5a which, through transistor 35, nullifies the signal on lead 5b. If a short-circuit fault appears on the output, the potential of the collector of the corresponding power transistor rises. Diodes connect all these points to a bi-stable transistor pair which switches in response to a fault and applies a signal to the inputs 5a of all the transistor units, thereby protecting all the power transistors against overload.