This device measures the low frequency signal of sinusoidal wave having frequency in integers.

1. 7-Segment Display Common Cathode -RED
2. IC CD4033
3. OpAmp UA709
4. Resistors and Capacitors
5. Batteries
6. Proteus 8 Professional

. This circuit is based on the simple definition of frequency, which is the number of cycles per second. Basically, a Square Wave Generator circuit (here we used schimdt trigger by using UA709) is used to produce a simple pulse wave. This pulse is given as clock[PIN 1] to CD4033 Counter. As we are measuring frequency so it is required that counting will be done for only 1 sec. So we input single pulse to clock inhinit [PIN 2]. So that untill the pulse is low, counter counts and as it will go high, the counting will stop. Since pulse is of duration 1 sec we will get the frequency of our input sinusoidal wave .