Patent ID: 6381116
Filing Date: 2002-04-30
Classification: H01H,H03K

Abstract:
A control device for an electromagnet comprising two power supply terminals, full-wave rectifying means having inputs connected to the power supply terminals, at least one coil connected in series with an electronic switch between outputs of the rectifying means, means for controlling the electronic switch and a local control terminal designed to be connected to one of the power supply terminals by local control means able to take two states, respectively open and closed, the control device comprising a first resistive dividing bridge, connected to the outputs of the rectifying means and comprising a mid-point connected to a first input of the control means of the electronic switch, and a second resistive dividing bridge, connected between the local control terminal and an output of the rectifying means and comprising a mid-point connected to a second input of the control means of the electronic switch, the control means comprising:quasi-simultaneous sampling means for supplying associated samples of the first and second voltages applied respectively to the first and second inputs of the control means, comparison means for comparison of a first quantity, representative of at least one non-null sample of the second voltage, and of a preset percentage of a second quantity, representative of associated samples of the first voltage, and detection means for detecting the state of the local control means, the local control means being considered closed when the first quantity is greater than said percentage.