Many devices require input pulses for their operation. Some device requires continuous train of pulses some requires single pulse. In some of the devices there is a provision to alter between continuous pulses and single pulse. For example a stepper motor controller can have two operating modes – auto and manual. In auto mode it requires continuous pulses to rotate motor continuously while in manual mode it requires single pulse to be generated when button is pressed manually.
The circuit presented here is 2 in 1 circuit that generates low frequency pulses in the output. It has two operating modes. In auto mode it generates pulses continuously and in manual mode it generates pulse when push button is pressed. The circuit is built using single IC555. To generate continuous pulses it is configured in astable mode and to generate single pulse it is configured in monostable mode.