Abstract: An electro-optical control system having a multi-key keypad, an alpha-numeric display, means for periodically generating a pulsed light beam, means for detecting a portion of the light beam to generate an analog signal, means for converting the analog signal to a digital signal and means for subtracting an ambient light level form the digital data to generate a difference signal. The difference signal is averaged and filtered to generate a digital signal level which is displayed on the alpha-numeric display. The electro-optical control system has two output switches which are activated when digital signal level is between programmed upper and lower limits for each output switch. The values of the upper and lower limits are programmable using the keypad. The upper and lower limits are displayed on the alpha-numeric display as they are generated.

Abstract: An electronic controller for generating a pair of mutually exclusive pulse train signals. The controller having an offset generator for biasing the input signal about a midpoint value, a first and second difference amplifier for generating a first and second difference signal, one difference signal corresponding to the difference between the biased input signal and the midpoint value and the other difference signal corresponding to the inverted difference between the biased input signal and the midpoint value, a saw tooth wave generator generating a saw tooth wave having its valleys clipped to a predetermined value, and a pair of comparators, one generating a pulse train signal in response to the saw tooth wave and the first difference signal and the other generating the second pulse train signal in response to the saw tooth wave and the second difference signal.