In the previous tutorial, different types of registers were discussed. The registers and counters are two types of sequential circuits that are solely build from flip flops. The counters are those registers that go through predetermined sequence of states on the application of input  pulses. The input pulses can be coming from a master clock or some external source. They may apply to the counter either at regular interval or randomly. There are two types of counters – Asynchronous counter (also known as ripple counter) and Synchronous counter.  

This circuit can be used in various projects where we require the counting. Like in doctors’ clinic or hospitals, in restaurants, in customer care offices where long queue is there and we want to stop the rush at the counter. This system is very effective where man power is less. In this you have to provide a token to the person and the person has to wait for its turn which can be displayed on the 7 segment display. With the help of this circuit we can maintain the silence and the person will also be informed about their turn.This circuit is based on 4026, a Johnson counter IC commonly used in digital display. It has a 5 stage Johnson decade counter with decoder which convert the Johnson code to a 7 segment decoded output 

CD4033 is a Johnson counter IC commonly used in digital display. It has a 5 stage Johnson decade counter with decoder which convert the Johnson code to a 7 [[wysiwyg_imageupload::]]segment decoded output. Means it will convert the input into numeric display which can be seen on 7 segment display or with the help of LED’s.Advantage of this IC is it can be operated at high voltage of 20V. But is highly sensitive, can detect emf present in the atmosphere and is sensitive to static charge also.  When you touch your finger at its input terminal its counter get started therefore care should be taken while using it. It can be used in various application like in 7 segment decimal display circuit, in clocks, timer etc. To understand its working first have a look on its pin diagram. Read more to find out how it is can be used in various applications.