Browse Prior Art Database

Conditional Power Return Circuit

IP.com Disclosure Number: IPCOM000080061D
Original Publication Date: 1973-Oct-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Davenport, DW: AUTHOR [+2]

Abstract

In the development of devices which are to be turned on or off by control signals over a communications line, it was found desirable to provide for continued operation of the device after periods of power interruption without further control action.

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Conditional Power Return Circuit

In the development of devices which are to be turned on or off by control signals over a communications line, it was found desirable to provide for continued operation of the device after periods of power interruption without further control action.

Such continued operation may be insured by using latched relays to switch the power supply to the device. As indicated, a controlled device 1 has its power supply 2 under control of a voltage on an input line 3. Application of voltage to line 3 will start the applicable power on routine for device 1 and termination of the voltage will start the power down routine. The voltage of line 3 is controlled by relay contact 4 of a latching type relay, having a pick coil 5 and a trip coil 6 to close and open contacts 4, respectively. Switches 7 and 8 are momentarily operable to connect the coils 5 and 6, respectively, to the control voltage supply line 9.

In use, a remote control signal is transmitted to operate switch 7 to close switch 4 and start a power-on cycle for the device, and similarly a control signal to operate switch 8 will release contacts 4 to start a power-down routine. Since the latch relay is mechanically held in on position, an interruption of power supply 2 and/or control voltage 9 will not change the condition of contacts 4 so that when power is again supplied, the device 1 will go through its power routine without any remote control action.

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