High accuracy achieved in A-C motor speed control

A solid-state development now gives industry a critically accurate and infinitely adjustable control of speed of single a-c motors or motor groups. It is called the AccurCon/200 inverter, and some of its accomplishments are: instant response to command from either local or remote control station; precise constant-frequency output, the key to motor speed control within 0.05 per cent of absolute; precise frequency output drift for extended periods of continuous operation; change of frequency output with the turn of a dial, automatically compensating to provide constant volts per cycles ordered for the motors in use; precise response to computer or automatic controller programming; exceptional harmonic neutralization, without filtering, and with elimination of all harmonics up to the eleventh; more than 90 per cent efficiency under normal load with noload loss of less than 6 per cent even at maximum frequencies; complete protection from momentary transients, continuing precise frequency output as ordered without pause; positive protection from overcurrents automatically through current-limit circuitry: continuous operation after component breakdown with reduced power level, allowing orderly motor and system shutdown; and the necessity for virtually no maintenance or servicing, with minimum parts inventory requirements because components can be interchanged.