Buzzer Circuit Controllable by a Microcomputer
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01
A reference square-wave signal of frequency F is used as a clock signal of D-type bistable. The output of the bistable is connected in a feedback loop to its input in series with an exclusive OR circuit (XOR), the other input of which is under control of an output of the microcomputer. The microcomputer output is used to control the phase of the signal applied to the input of the bistable. Whenever the signal is active low, the bistable is changing of state on every clock cycle, dividing the clock frequency by two, thereby providing at the output a signal of frequency F/2. Whenever the signal is active high, the output of the bistable remains steady and provides the signal of frequency F.