Circuit arrangement for monitoring a current-consuming load
First Claim
1. A device for monitoring DC current conducted to a grounded load from a supply voltage source through a conductor about which a magnetic field is established by said current, comprising measuring coil means physically arranged in parallel with the conductor and operatively positioned within said magnetic field for sensing changes in current conducted to the load, an operational amplifier having non-inverting and inverting input terminals, an output terminal and a feedback resistance connected between the output terminal and the non-inverting input terminal, a grounded capacitor connected to the inverting input terminal, a series resistor connecting the measuring coil means output to the non-inverting input terminal, an electrical fault indicator connected to the output terminal, and voltage divider means interconnected between the source and ground for regulating voltages applied to the measuring coil means and the inverting input terminal of the operational amplifier, said measuring coil means having its input connected to said voltage divider, and said operational amplifier having its inverting input terminal connected to said voltage divider through a resistor.
0 Assignments
0 Petitions
Accused Products
Abstract
Circuit arrangement for monitoring an electricity-consuming load fed with direct current one terminal of which is grounded, particularly for monitoring an incandescent of an automotive vehicle, and the circuit arrangement being installable without interfering with the existing network of lines or cutting conductors. Between the switch of the load and the current-consuming device a measurement coil is arranged parallel to a conductor within the magnetic field produced by the flow of electricity through the conductor, the input of the coil being connected to a voltage supply source and its output being connected in a Schmitt trigger circuit with the non-inverting input of a differential amplifier constituted as operational amplifier and the output of the amplifier being fed back via a resistor to the non-inverting input and being connected to a fault indicator.
41 Citations
12 Claims
- 1. A device for monitoring DC current conducted to a grounded load from a supply voltage source through a conductor about which a magnetic field is established by said current, comprising measuring coil means physically arranged in parallel with the conductor and operatively positioned within said magnetic field for sensing changes in current conducted to the load, an operational amplifier having non-inverting and inverting input terminals, an output terminal and a feedback resistance connected between the output terminal and the non-inverting input terminal, a grounded capacitor connected to the inverting input terminal, a series resistor connecting the measuring coil means output to the non-inverting input terminal, an electrical fault indicator connected to the output terminal, and voltage divider means interconnected between the source and ground for regulating voltages applied to the measuring coil means and the inverting input terminal of the operational amplifier, said measuring coil means having its input connected to said voltage divider, and said operational amplifier having its inverting input terminal connected to said voltage divider through a resistor.
Specification