This article is based on the clamper circuit, working of positive and negative clamper circuits and the applications of clamper circuits using different waveforms and circuit.
In our previous articles, we learn about diodes and the working of diodes and the applications of the diode as half wave rectifier, full wave rectifier, clipper circuits. And in this article, we are moving forward to learn about clamper circuit and their working.
What is Clamper Diode?
A Diode Clamper (DC restorer) is a circuit which changes the dc reference of an ac signal. Basically, a clamping diode circuit(or a clamper) essentially adds a d.c. component of the ac signal
- Here one thing is notable that the shape of the original signal is same it is not changed in the output just the reference is shifted vertically this is achieved with clamper circuit.
There are two types of Clamper Diode circuits:
- Positive Clamper Diode
- Negative Clamper Diode
What is Positive Clamper Diode:
If a vertical shift is achieved in Positive direction i.e. if the signal is pushed up so that the negative peaks falls on the zero level then the clamper is called a positive clamper.
What is Negative Clamper Diode:
The negative clamper diode does the reverse i.e. it pushes the signal downwards so that the positive peaks fall on the zero level.
The following point may be noted carefully:
- The clamping circuit does not change the peak-to-peak or r.m.s. value of the waveform. If you measure the input voltage and clamped output with an a.c. voltmeter, the readings will be the same.
Working of Positive Clamper Diode:
To understand the working of positive clamper we are applying negative half cycle of the input voltage. When the negative input voltage is applied, the diode is forward biased, allowing the capacitor to charge to almost the peak of the input (Vp(in)-0.7). shown in fig (a).
Just after the negative cycle, the diode is reverse bias and capacitor which was charged during the negative cycle that has to now discharge. Which means all the voltage will be summed producing double of Vp(in) at load. Here the amplitude is same just output is clamped. i.e if input Vp was 5v then the clamped output is nearly 10 practically (10-0.7), as shown in fig (b).
Working of Negative Clamper Diode:
Reverse the diode and apply positive half cycle first, during positive half cycle of input the diode is forward bias and the capacitor is charging up to (Vp(in)-0.7) after the positive cycle when negative cycle of input comes our diode is reverse bias which means the charged capacitor has to discharge so the voltage will be summed (vp+vc1) and the summed voltage will appear at output (Load resistor) hence such type of clamper is known as Negative clamper diode which clamp or pushes the output waveform downwards to the reference.
Watch the Video of Clamper Diode Circuit:
Applications of Clamper Diode Circuit:
- Clampers are mostly used in test equipment, sonar, and radar systems.
- They are widely used for their common application of voltage doubles or voltage multipliers.
- Clampers are mostly used for removing the distortions
- In the transmitting and receiving circuitry of television a clamper is used to stabilize to define sections of the luminance signals to preset levels.
- Clampers are used to provide protection to the amplifiers from large errant signals.
- They are commonly used for the analysis of synchronized signals from the composite visual signals.
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