NE555 astable generates a clock for the circuit, which provides an oscillating wave to the output pin 3 of IC1. You can vary the speed of oscillation with the help of VR1. The frequency of oscillation of 555 timer can be calculated by: f=1.44/(R1+2*(VR1)*C1) Now this wave is supplied to CD4017 decade counter pin 14…
Shown here is an easy to construct electronic circuit through which a motor can be made to run in both directions i.e. clockwise and anticlockwise. An interesting [[wysiwyg_imageupload::]]fact that adds to the curiosity of the circuit is that this is done by pressing a single switch. This project finds a good application in areas of robotics. The commonly used H-Bridge circuit uses two control signals to control both the directions of the motor. Before we begin explaining the circuitry, let’s have some information about the H-Bridge circuit.H Bridge CircuitMainly used to control DC motors and stepper motors, H-bridge divides the voltage on the either side of the load. In this circuit, two IC555 timers form the H-bridge circuit around the motor. These 555 timers work in astable mode. Let’s find out more about how the circuit works.
Activation and control of appliances through sound has always been fascinating. Imagine entering your room and switching on your lights/fan with sound of your [[wysiwyg_imageupload::]]flick. The circuit based project described here can be used to alternately switch on and off an electrical appliance. The idea is to take sonic input through a condenser mic and control the appliance at the output through a relay. The input is amplified for better sensitivity and supplied to a counter. This counter is configured to give alternate high and low pulses to the relay which in turn controls the device connected to it.In this project, the condenser mic converts the sound signal sensed from the surroundings and converts them into the weak electrical signals and the transistor amplifying circuit amplifies the weak signals. Refer sound amplifier circuit for more details.The circuit uses an optocoupler IC 4N350 to provide pulses to the counter IC 4017. An optocoupler is a 6 pin IC which contains a led, optically coupled to a phototransistor.
This project describes the functioning of the traffic light system, which are commonly used on the streets. In this circuit 555 timer is used to produce a clock [[wysiwyg_imageupload::]]pulses, which are used by a counter to produce the required output. Mentioned below are a few interesting facts about this circuit:· The 555 timer is used in its astable mode.· Besides 555 IC, a 4017 IC which is CMOS decade counter is also used in this circuit.· A bypass capacitor too is used in the circuit. Read more to find out how the circuit can be constructed and how it works.