Circuit for intrinsically safe pilot light

DETAILED DESCRIPTION We claim: 1.
A circuit for an intrinsically safe pilot light comprising: a plurality of light emitting diodes connected in series, a pair of terminals connected to an intrinsically safe electric source, a full wave bridge rectifier connected in a circuit between the terminals and the series connected diodes for supplying the diodes with controlled polarity direct current regardless of the polarity of the source, and a current regulator connected in the circuit for maintaining constant the current supplied to the diodes upon failure of any of the diodes and to maintain the current at a value to optimize brightness of the diodes.
2.
The circuit as set forth in claim 1 wherein the diodes are mounted on a board having a printed circuit that connects the diodes inseries and provides a reflecting surface for the light emitted by the diodes.
3.
The circuit as recited in claim 2 including a second printed board and wherein the full wave bridge rectifier and the current regulator have components connected by a printed circuit on the second board.
4.
The circuit as recited in claim 3 wherein the first mentioned printed circuit board and the second printed circuit board are physically maintained in spaced relation by a plurality of conductive support that provide an electrical connection between the circuits on said boards.
5.
The circuit as recited in claim 4 wherein one of the conductive supports is a fuse.
6.
The circuit as set forth in claim 5 wherein the diodes are mounted on a board having a printed circuit that connects the diodes in series and provides a reflecting surface for the light emitted by the diodes.
7.
The circuit as recited in claim 6 including a second printed board and wherein the full wave bridge rectifier and the current regulator have components connected by a printed circuit on the second board.
8.
The circuit as recited in claim 6 wherein the first mentioned printed circuit board and the second printed circuit board are physically maintained in spaced relation by a plurality of conductive support that provide an electrical connection between the circuits on said boards