Microcomputer-Based Payload Checkout System

A microcomputer-based system using Intel's 8085A microprocessor has been developed for the ground check-out of the rocket-borne instruments used for measuring electric field and electron density in the upper atmosphere. The complete system consists of an SDK-85 microcomputer, a 10 nA to 0.5 mA current source, an exponential sweep-frequency generator and analogue I/O modules. In addition to this, an audio cassette recorder and a printer are also included in the system.The sweep-frequency generator sweeps the entire frequency range of 50 Hz to 5 kHz in exponential steps. The current source has been realized by a set of resistors connected to a voltage source through programmable FET switches and is used for the calibration of a Langmuir probe payload. The audio cassette recorder is being used for mass storage of programmes and data.