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Protection and Indicating Circuit

IP.com Disclosure Number: IPCOM000098671D
Original Publication Date: 1959-Aug-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Levitre, EJ: AUTHOR

Abstract

Protection of a transistorized series voltage regulator SVR from shorts or excessive voltage fluctuations and an indication of their occurrence are provided by a circuit which requires a minimum number of components. In the circuit, transistors T(1) and T(2) are connected to the output line of the regulator. A normally de-energized latch-type relay R(1) is associated with transistor T(1) and a similar type relay R(2) is associated with transistor T(2).

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Protection and Indicating Circuit

Protection of a transistorized series voltage regulator SVR from shorts or excessive voltage fluctuations and an indication of their occurrence are provided by a circuit which requires a minimum number of components. In the circuit, transistors T(1) and T(2) are connected to the output line of the regulator. A normally de-energized latch-type relay R(1) is associated with transistor T(1) and a similar type relay R(2) is associated with transistor T(2).

Transistor T(1) is normally biased off by a voltage X which is established at a level more negative than the normal regulator output voltage. Voltage X is obtained from the external reference voltage supply RV at terminal 1. In a like manner, transistor T(2) is normally biased off by a voltage Y which is established at a level more positive than the normal regulator output voltage. Voltage Y is obtained from the input voltage V(1) at terminal 2.

If the output of the regulator becomes more negative than allowable, the X bias on T(1) is no longer effective. T(1) conducts and relay pickup coil RP1 is energized to open relay points R1a, R1b and shift transfer points R1c. An excessive voltage fluctuation in the positive direction, on the other hand, causes energization of pickup coil RP2 through transistor T(2) to operate points R2a, R2b and R2c.

The normally closed a points of a particular relay serve to open both its pickup coil circuit and the collector circuit of its associated tran...