Indicator circuit for monitoring pulses initiated in a remote meter reading system

Claim 1

An indicator circuit for monitoring a three wire remote meter reading telemetry system wherein the system includes a watthour induction meter having a measuring winding means, a switch having first and second closing contacts for effecting alternate closures with a common contact in response to movement of said meter, and a remote receiver circuit including a source of alternating current and a pair of diodes, each of said diodes being connected in a mutually opposite polarity relationship between said source and one of said closing contacts to develop positive and negative pulse signals in response to the alternate switch closures, said indicator circuit comprising: first and second light emitting diodes mounted on said meter, said first light emitting diode having one electrode of a given polarity connected to said first closing contact and said second light emitting diode having one electrode of an opposite polarity connected to said second closing contact, the electrode of the light emitting diode and the electrode of the diode of said pair which are commonly connected to the same closing contact being of mutually opposite polarities; and an auxiliary winding means inductively coupled to said measuring winding means and being connected between the remaining electrodes of said first and second light emitting diodes and said common contact so that upon excitation of said auxiliary winding means the light emitting diodes are separately energized so as to visually display at said meter an indication correspondingly responsive to each of the alternate switch closures and currently responsive to the proper operation of said measuring winding means with the reverse current blocking characteristics of said light emitting diodes being poled so as to prevent current of said alternating current source from flowing into said indicator circuit.