Symmetrical controlled switching circuit

• US 5,118,963 A
• Filed: 11/29/1989
• Issued: 06/02/1992
• Est. Priority Date: 11/29/1989
• Status: Expired due to Fees

• Current Assignee: Pepperl + Fuchs GmbH
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Gesin, Milford M.
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Osborn, David
• Application Number:
  US07/445,830
• Time in Patent Office: 916 Days
• Field of Search: 307/11, 307/18, 307/19, 307/23, 307/29, 307/30, 307/31, 307/32, 307/38-40, 307/51-53, 307/43-48, 307/64-66, 307/643, 307/645, 307/648, 307/638, 307/113, 307/115, 307/145 , 307/146, 307/116
• US Class Current: 307/116
• CPC Class Codes: H03K 17/79 controlling bipolar semiconductor switches with more than two PN-junctions, or more than three electrodes, or more than one electrode connected to the same conductivity region

Abstract

A switching circuit is disclosed which provides a plurality of switches which can be caused to open or close, a controller which can selectively draw current from a plurality of power sources connected in electrical communication with the switches and isolating devices connecting the switches to the controller. The controller is connected to a regulator and to one voltage interconnection and the regulator is connected to another voltage interconnection by two conductive paths which control individual switches that are associated with individual power supplying loads.

Claims

1. A switching circuit for controlling a plurality of external load circuits, comprising:

a first voltage interconnection;

a second voltage interconnection, a first portion of each of said first and second interconnections being connectable to a first load and a first power supply, a second portion of each of said first and second voltage interconnections being connectable to a second load and a second power supply;

a regulator connected between said first voltage interconnection and said second voltage interconnection between said first and second portions of said first and second voltage interconnections, said regulator being connected by first and second parallel conductive paths to said first voltage interconnection, said first conductive path comprising a semiconductive switch, said second conductive path comprising a means for providing a voltage differential between said first voltage interconnection and said regulator;

a transducer connected between said regulator and said second voltage interconnection, said transducer having an output which is switchable between first and second conditions in response to a stimulus, said output being connected to said semiconductive switch to cause said semiconductive switch to assume a conductive state in response to said first condition and to assume a nonconductive state in response to said second condition;

a first switching device connected between said first and second voltage interconnections at both said first portions and operatively coupled to said first conductive path to connect said first and second voltage interconnections in electrical communication with each other in response to electrical current passing through said first conductive path; and

a second switching device connected between said first and second voltage interconnections at said second portion and operatively coupled to said second conductive path to connect said first and second voltage interconnections in electrical communications with each other in response to electrical current passing through said second path.

2. The circuit of claim 1, further comprising:

a first light emitting diode connected in series with said semiconductor switch in said first conductive path and a second light emitting diode connected in series with said voltage differential providing means in said second conductive path.

3. The circuit of claim 1, further comprising:

means for preventing electrical communication between said first and second switching devices.

4. The circuit of claim 1, wherein:

said voltage differential providing means is a diode.

5. The circuit of claim 1, wherein:

said first switching device is operatively coupled to said first conductive path by an optical isolation component.

6. The circuit of claim 1, wherein:

said semiconductive switch is a MOSFET.

7. The circuit of claim 1, further comprising:

means for preventing electrical communication between said first and second portions of said first and second voltage interconnections.

8. The circuit of claim 7, wherein:

said preventing means comprises a first pair of diodes connected to said first voltage interconnection and a second pair of diodes connected to said second voltage interconnection, said first and second pairs of diodes each comprising diodes arranged in opposite polarity relation with each other, said first and second conductive paths being connected in electrical communication with a point between said first pair of diodes.