Emergency D.C. power supply with the emergency state being indicated by polarity reversal
First Claim
1. An emergency D.C. electrical power supply with emergency status being indicated by polarity reversal, wherein the power supply comprises a main D.C. electrical power source provided with a protection device causing its output to go to a high impedance state in the absence of a voltage across its terminals, and an auxiliary D.C. electricity power source connected in parallel and in opposition with the main source and provided with a current limiting device which is normally tripped by the additional current which the main source attempts to impose thereon.
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Accused Products
Abstract
This power supply is intended, more particularly, for powering a user digital terminal from a remote terminal in an integrated service digital telephone network. It comprises a main D.C. electricity power source (10) provided with a protection device (11) causing its output to go to a high impedance state in the absence of a voltage across its terminals, and an auxiliary D.C. electricity power source (20) connected in parallel and in opposition with the main source (10) and provided with a current limiting device (20) which is normally tripped by the additional current which the main source (10) attempts to impose thereon.
73 Citations
9 Claims
- 1. An emergency D.C. electrical power supply with emergency status being indicated by polarity reversal, wherein the power supply comprises a main D.C. electrical power source provided with a protection device causing its output to go to a high impedance state in the absence of a voltage across its terminals, and an auxiliary D.C. electricity power source connected in parallel and in opposition with the main source and provided with a current limiting device which is normally tripped by the additional current which the main source attempts to impose thereon.
Specification