A Miniature Transmitter for Telemetering Muscle Potentials

A miniature transmitter was designed to telemeter muscle potentials from dogs. The implanted transmitter is operated by a nickel-cadmium battery. In order to obtain information over long periods of time, the battery is recharged by induction from an external power source. By using the oscillator transistor in an inverted configuration, the transmitter's circuit serves to recharge the battery without the addition of extra components. The simplicity of the circuit makes the unit compact and minimizes the failure of components. A magnetic switch is used to actuate the circuit, thus eliminating complete drain and degeneration of the battery.