The transmitter consists of an oscillator which drives a high output IR emitting diode. The oscillator is a sJire start multivibrator circuit that provides an output of 15 to 1000 mark to space ratio at a frequency of 1 kHz. This large mark to space ratio allows the IR diode to be operated at a high peak current, provided by the ZTX600 Darlington transistor, to maximize the transmitter range.
A decoupling network is included in the power supply lead to isolate it from any logic circuitry using the same 5-V power supply source. The transmitter supply current is approximately 65 mA.