US 5,289,131 A · Circuit configuration for monitoring an electromagnetically actuated device, in particular an electromagnetic clutch

Abstract

A circuit configuration is provided for monitoring an electromagnetically actuated device, such as an electromagnetic clutch. The circuit comprises a switchable power source connected to the winding of the electromagnet; the power source supplies a composite voltage formed of a direct voltage part and a periodic alternating voltage part superimposed on one another. Engage and disengage signals are issued for the clutch and the direct voltage part assumes distinctly different levels in dependence on the engage and disengage signals. A precision resistor is connected in series with the winding of the electromagnet and a voltage sensor is connected at a node between the winding and the precision resistor. An evaluation circuit is connected to the voltage sensor for evaluating the alternating voltage part acting on the precision resistor and receiving therefrom information regarding the functionality of the electromagnetic device.

Claims11

Dependent claims

Circuit configuration for monitoring an electromagnetically actuated device having an electromagnet with a winding, comprising a switchable power source connected to the winding of the electromagnet, the power source being means for supplying a voltage formed of a direct voltage part and a periodic alternating voltage part superimposed on the direct voltage part, means for issuing engage and disengage signals for the electromagnetic device and for providing said direct voltage part at two defined levels in dependence on said engage and disengage signals, a precision resistor connected in series with the winding of the electromagnet, a voltage sensor connected at a node between the winding and said precision resistor, and an evaluation circuit connected to said voltage sensor for evaluating the alternating voltage part acting on said precision resistor.

Circuit configuration for monitoring an electromagnetic device having an electromagnet with a winding, comprising

direct voltage means for supplying a direct voltage at two distinctly different voltage levels;
alternating voltage means for supplying a periodically alternating voltage with a given period of oscillation;
power source means for superimposing said direct and alternating voltages on one another for forming a composite voltage having a direct voltage part and an alternating voltage part, and for switching said direct voltage part to a relatively low level upon issuance of a disengage signal for the electromagnetic device, and for switching said direct voltage part to a relatively higher level upon issuance of an engage signal for the device;
said power source means remaining connected to the winding of the electromagnet independently of said engage or disengage signals;
voltage evaluation circuit means connected to the winding of the electromagnet for evaluating a voltage at the winding and determining a state of the electromagnetic device.

2 more elements

Dependencies are inferred from the claim text.

Circuit configuration for monitoring an electromagnetically actuated device, in particular an electromagnetic clutch

Life of this patent

Circuit configuration for monitoring an electromagnetically actuated device, in particular an electromagnetic clutch

Life of this patent

Abstract

Claims11