Electrically Controlled Braking Apparatus

Abstract

Abstract 1,174,245. Magnetic amplifiers; transistor amplifiers. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. 11 April, 1968 [26 April, 1967], No. 19234/67. Headings 113B and H3T. [Also in Divisions F2 and G1] Magnetic amplifiers. Summing circuits.-In a vehicle braking system the control signals are summed in an auto-self-excited, full-waverectifying, transductor with a step-functioncharacteristic to take up the slack in the brakes between coasting and a brake application. As shown, Fig. 3, the transductor is provided with summing control windings 108, 109, 110, bias winding 111, and negative feedback winding 112. The step-function is produced by applying the command signal on line 24 to winding 108 and to a transistor 124 which cuts off at a predetermined value to cause a small change in the bias through winding 111. Constant current circuit, Fig. 3.-The output of the summing transductor at the top of Fig. 3 is applied to a further self-excited transductor 140 to provide selected control currents (according to the command signal) which are independent of normal variations in load but limited during traction. The transductor comprises a current, feedback winding 147, bias winding 148, control windings 149 and current limiting winding 150 feed from resistor 156 through Zener limit " diode 155, and diode 158 so that it is only effective during traction. Transistor amplifiers, Fig. 2c.-A D.C. coupled transistor amplifier 68, 71, 74 has overall negative feedback via capacitor 79 and resistor 80. D.C. stabilization is provided via resistor 81. A similar amplifier is depicted in Fig. 2b (not shown). Limited rate-of-change signal. Fig. 46.-In a jerk-control-circuit to limit the rate of braking or acceleration of a vehicle, the control signal is applied to a small capacitor 221 and a larger capacitor 233a is charged or discharged to the same value through transistors 228, 229. When the rate of change of signal on capacitor 221 exceeds the rate of change on capacitor 233a, one of the diodes 223 or 225 in the bridge 223 ... 6 blocks so that the charge or discharge rate is determined by transistor 228 ... 9.

Inventors

• 👤 Arthur Maskery

Bibliographic Details