Drive circuit for an electromagnetic relay

摘要

A drive circuit for an electromagnetic relay having a relay coil and switch contacts, includes a first switching device between a first coil terminal and a first voltage source, a second switching device between a second coil terminal and a zero potential, and a control device producing a current through the coil closing both switching devices. To provide the shortest possible response time and simple and cost-effective construction, a second voltage source is connected through a third switching device to the first coil terminal. The third switching device is connected in parallel with the first switching device, the second voltage source has a higher voltage level than the first voltage source and the control device produces a current through the coil, initially closing all three switching devices and following expiration of a predefined period, opening the third switching device again and keep the first and second switching devices closed.

主权项

1. A drive circuit for an electromagnetic relay having switch contacts and a relay coil with first and second terminals, the drive circuit comprising:
a first voltage source and a second voltage source, said second voltage source having a higher voltage level than said first voltage source; a first switching device disposed between the first terminal of the relay coil and said first voltage source; a second switching device disposed between the second terminal of the relay coil and a zero potential; a third switching device connected between said second voltage source and the first terminal of the relay coil, said third switching device connected parallel to said first switching device; and a control device configured to initially close said first, second and third switching devices to produce a current flow through the relay coil and to open said third switching device again and keep said first and second switching devices closed at an end of a predefined time period.