A low level commutation system for telemetry application

The problems encountered in designing a satisfactory low-level commutation system for thermocouple signals are discussed and the capabilities of the system are outlined. The system as designed is capable of handling grounded, ungrounded and partially grounded thermocouples whose output voltages vary from zero to 10 millivolts. The sampled millivolt output signals are amplified and utilized in a PAM/FM/FM telemetry system meeting the requirements established in the I.R.I.G. standards.