Digitally controlling power output of IC engine - using register latch set to predetermined non-critical value for PWM upon microprocessor failure

摘要

The throttle flap (7) is rotated by a motor (6) driven by the output stage (5) of a regulator (4) which responds to a square-wave signal (12) from a pulse width modulator (11) in the control circuit (3) clocked by a microprocessor (1). A set-point value is computed and applied over a 10-bit parallel data line (2) to a register (10), which is read out to the modulator and then reset by another output from the clock generator (13). ADVANTAGE - Set-point held at safe level allowing engine to be stopped or run at emergency speed after failure of program execution by microprocessor.