Circuit arrangement for switching on solenoid valves

• Main Authors: THOMAS,GERD, HAUBNER,GEORG, ERETH,WALTER
• Format: Patent
• Language: English; German
• Published: 15.05.1986
• Edition: 4
• Subjects: ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; BASIC ELECTRIC ELEMENTS; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ELECTRICITY; INDUCTANCES; MAGNETS; PERFORMING OPERATIONS; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OFVEHICLES; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TRANSPORTING; VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES; VEHICLES IN GENERAL

A circuit arrangement for switching on solenoid valves is proposed, which is intended to ensure damped connection of a hydraulic-oil supply to a hydraulic system. For this purpose, a triangular-waveform generator (12) is provided on whose output side a comparator (13) and a switching stage (11) for the solenoid valve (10) are connected, rectangular-waveform pulses occurring at the output of the comparator (13), in time with the voltage of the triangular-waveform generator (12), the pulse width of which rectangular-waveform pulses is dependent on the magnitude of a control signal which is applied to the second input of the comparator (13). A ramp generator (15) for producing the control signal is connected to the second input of the comparator (13) in such a manner that, with the falling edge of the control signal, the width of the rectangular-waveform pulses at the output of the comparator (13) increases up to 100% of the cycle duration of the triangular-waveform generator (12) and hence causes the solenoid valve (10) to switch on gradually.