Switch device suitable for use in automotive vehicles
AssigneeVDO Adolf Schindling AG
InventorWerner Wallrafen
Life of this patent
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Abstract
In a switch device, suitable for use as active sensor in an automotive vehicle, wherein current through a load can be switched as a function of a physical variable acting on the switch device, two terminals of the switch device can be connected together via a semiconductor switch. They also form the input of a current supply circuit. A sensor produces an electric signal which represents the physical variable and which can be fed to a threshold circuit. The semiconductor switch is controllable in pulsating manner as a function of the output signal of the threshold circuit.
Claims17
A switch device serving to switch current through a load as a function of a physical variable acting on the switch device, the switch device comprising:
- two terminals serving to connect the switch device to said load;
- a semiconductor switch interconnecting the two terminals and having a control electrode;
- a voltage stabilization circuit having an output terminal and being connected between the two terminals to be energizable via the two terminals;
- a sensor which produces an electric signal representing a physical variable, the sensor being connected between the output terminal of the voltage stabilization circuit and one of the two terminals;
- a threshold circuit coupled to an output terminal of said sensor;
- and
- pulsating means for operating the semiconductor switch in pulsating manner as a function of an output signal of the threshold circuit;
- wherein said pulsating means include a pulse generator and a logic element, said generator producing a train of output pulse signals at a predetermined frequency, output signals of the threshold circuit and of the pulse generator being applied via the logic element to the control electrode of the semiconductor switch;
- in a first state of the semiconductor switch, the pulsating means places the semiconductor switch in a mainly nonconductive mode allowing for pulsations with a large pulse-duty factor including 1.0;
- and
- in a second state of the semiconductor switch, the pulsating means places the semiconductor switch in a pulsating nonconductive mode with a small pulse-duty factor.
A switch device serving to switch current through a load as a function of a physical variable acting on the switch device, the switch device comprising:
- a first terminal and a second terminal by which the switch device is to be connected to the load and to a source of power, the source of power providing power to the load and to the switch device;
- a semiconductor switch interconnecting said first terminal and said second terminal;
- a diode rectifier connected to said first terminal, and a capacitor connected in series between said diode rectifier and said second terminal;
- a voltage stabilization circuit connected to a junction of said diode rectifier and said capacitor, a reference voltage source connected to said second terminal, and a sensor connected between said voltage stabilization circuit and said second terminal;
- a threshold circuit having a first input terminal for receiving an output signal of said sensor, and a second input terminal for receiving a reference voltage outputted by said reference-voltage source;
- and
- pulsating means for operating the semiconductor switch in a pulsating manner as a function of an output signal of the threshold circuit to provide a pulsating current to the load, the pulsating means including a pulse generator and a logic element, said logic element receiving signals outputted by said pulse generator and said threshold circuit, said logic element outputting a pulsating signal to a control terminal of said switch wherein a pulse duty factor of the pulsating signal and of the pulsating current is varied by the sensor output.
Dependencies are inferred from the claim text.