Patent ID: 6381114
Filing Date: 2002-04-30
Classification: G05F,H02H

Abstract:
An intrinsically safe circuit configured for supplying power to a load connected to a first output terminal and a second output terminal, said circuit comprising:a power supply source; a voltage limiter connected in parallel with said power supply source to limit a maximum voltage generated by said power supply source; a connection between a first side of said voltage limiter and said first terminal; and a current limiter comprising; a reference voltage, a variable impedance, a barrier resistor, and a second side of said voltage limiter is connected in series with said barrier resistor and said variable impedance to said second output terminal, said current limiter limits a current delivered to said load via said terminals to a maximum current level in response to a comparison of said reference voltage with a voltage across said barrier resistor representative of the current delivered to said load.