Electronic identification device

Claim 1

An identification device for generating a train of pulses, each of said pulses having a respective first or second polarity according to a code identifying said device, responsive to a single input signal applied thereto, said input signal having a predetermined duration, said device comprising: (A) a pulse generating circuit having a trigger input and two outputs and being capable of generating a train of pulses responsive to a single trigger signal applied to said trigger input, each of the pulses in said train of pulses being applied to one of said outputs, the particular one of said outputs to which each respective one of said pulses is applied being determined by said code; (B) a rectifier circuit for both supplying power to said device and for applying said trigger signal to said trigger input responsive to said single input signal, said rectifier circuit comprising (1) a first diode coupled in series with a first capacitor, said first capacitor being coupled to said trigger input; (2) a second diode coupled in series with a second capacitor, said second capacitor having a considerably greater capacitance than said first capacitor and being coupled to a power supply input of said pulse generator circuit; and (3) a first inductive means inductively receiving said input signal and applying said input signal to said first and second capacitors whereby said first capacitor serves as a trigger signal source and said second capacitor serves as a power source; and (C) inductive means coupled to said two outputs of said pulse generator circuit for inductively transferring said pulses to a detector circuit.