Circuit arrangement having a semiconductor switch for the switching of a load
AssigneeVDO Adolf Schindling AG
InventorWalter Kares
Life of this patent
Estimating the term…
Abstract
In a circuit arrangement having a semiconductor switch for the switching of a load, in particular of a setting member in manual or automatic control devices, as a function of a switch signal which is fed, a device for disconnect in the event of a short-circuit being adapted to be controlled by a current sensor over a filter, the device for the disconnecting can furthermore be actuated via a logic circuit by the switch signal and by an output signal of a detector for an overvoltage at the semiconductor switch in such a manner that disconnect takes place when an overvoltage is present and the switch signal assumes a level intended for connection.
Claims5
A switch control circuit having a semiconductor switch for switching a load in response to a switch signal, the circuit further comprising:
- a current sensor for sensing current in the semiconductor switch, a device for disconnection of said current in the event of a short circuit in the load, and a low-pass filter connecting an output of said sensor to said disconnection device;
- a logic circuit having a first input and a second input, and an overvoltage detector for detecting an overvoltage on the semiconductor switch;
- wherein said load and said semiconductor switch and said current sensor are serially connected between terminals of a source of power providing for a flow of current through said load and said switch and said sensor;
- a junction between the load and the semiconductor switch is connected via said detector directly to said first input of said logic circuit, and said second input of said logic circuit receives said switch signal;
- and
- an output of said logic circuit activates said disconnection device to disconnect said current in the presence of said overvoltage and upon said switch signal assuming a connect level for activating said semiconductor switch to connect the load.
A switch control circuit having a semiconductor switch for switching a load in response to a switch signal, the circuit further comprising:
- a current sensor for sensing current in the semiconductor switch, a device for disconnection of said current in the event of a short circuit in the load, and a filter connecting an output of said sensor to said disconnection device;
- a logic circuit having a first input and a second input, and an overvoltage detector for detecting an overvoltage on the semiconductor switch;
- wherein a junction between the load and the semiconductor switch is connected via said detector directly to said first input of said logic circuit, and said second input of said logic circuit receives said switch signal;
- an output of said logic circuit activates said disconnection device to disconnect said current in the presence of said overvoltage and upon said switch signal assuming a connect level for activating said semiconductor switch to connect the load;
- and
- a transistor circuit directly coupled between an output terminal of said overvoltage detector and a control terminal of said semiconductor switch for termination of current flow in said semiconductor switch upon the occurrence of an overvoltage.
Dependencies are inferred from the claim text.