CD4033 is a Johnson counter IC commonly used in digital display. It has a 5 stage Johnson decade counter with decoder which converts the Johnson code to a 7 segment decoded output. This 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 because it is highly sensitive and it can detect EMF presence in the atmosphere and it is sensitive to static charge also.When you touch the input terminal with finger, counter get’s started.Therefore care should be taken while using it. It can be used in various applications like in 7 segments decimal display circuit, in clocks, timer etc. To understand its working we have a look on its pin diagram –
Now let us understand the working of individual pins-
1. Pin 1 known as Clock in – It receives clock signals, and at every positive clock counter advances one by one. You can provide clock with the switch, 555 timer or with the help of logic gates.
2. Pin 2 known as Clock inhibit – CD4033 counter advances one by one by receiving positive pulse . This time clock inhibit pin should be grounded. If it is connected to supply than counter advancement will be inhibited which means there will be no meaning of clock pulse.
3. Pin 3 and pin 4 known as Ripple blanking in and Ripple blanking – It is used to display only one zero blanking the other zero. For this, IC has ripple blanking in and ripples blanking out. For example you want to display 345 and you are using five 7 segment display then it will display 00345 if blanking input and out is OFF. But if it is ON than you will receive 345. It improves the readability of the circuit.
4. Pin 5 known as carry out – It is used to complete one cycle for every 10 clock input cycle and it also used to cascade more IC’s.
5. Pin 6, pin7 and Pin9 to pin 13 – These are 7 decoded output from A to G, used to illuminate the corresponding segment of 7 segments display to display the digit from 0 to 9.
6. Pin 14 known as Lamp test – It is used to check and ensure that all segments of 7 segments is working properly or not. For testing momentarily make the pin low.
7. Pin 15 known as Reset – It is used to reset the counter. When it receives high it clears the counter and counting again starts from zero. One important thing reset pin should be made low again to start the counter once again.
8. Pin 8 known as ground pin and Pin 16 known as Vdd -It should be connected to power supply.
Working of Radiation Sesnor Circuit
Circuit shown in the tab can be used to detect the electromagnetic radiation or EMF present around it. The radiation may come from TV, computer etc.
Working of circuit is simple, whenever it detects radiation it receive clock at pin 1 and its counter starts and common cathode connected display connected through it starts fluctuating. It will show you any random number on display. And the cycle repeats till the reset pin receives high at its input. And when you put it away from radiation the number which will be displayed is constant.
Therefore from this circuit you can detect the electromagnetic waves present in your home.
Filed Under: Electronic Projects