Patent ID: 6341493
Filing Date: 2002-01-29
Classification: G08C

Abstract:
A control adapted to monitor an operating status of a system in response to receiving an input voltage having an input voltage amplitude and a nominal frequency, said control comprising:an input terminal adapted to receive said input voltage; a first pulse circuit coupled to said input terminal and adapted to generate a first pulsating voltage having a first frequency that varies as a function of said input voltage amplitude with said first frequency being at least as great as said nominal frequency when said input voltage amplitude is above an upper limit; a second pulse circuit adapted to generate a plurality of pulses in response to said first pulsating voltage; an electrical isolator that helps isolate said plurality of pulses from said input voltage; and a logic circuit coupled to said second pulse circuit and selectively creating a first binary value in response to said plurality of pulses indicating said input voltage amplitude is above said upper limit and creating an opposite binary value in response to said plurality of pulses indicating said input voltage amplitude is below a lower limit, whereby said first binary value and said opposite binary value at least partially provide an indication of said operating status of said system.