Diode Biased Limiters/Clippers
First read basics of Diode Clippers. Click Here to read
The level to which an ac voltage is limited can be adjusted by adding a bias voltage, VBIAS, in series with the diode, as shown in Below Figure. The voltage at point A must equal VBIAS + 0.7 V before the diode will become forward-biased and conduct. Once the diode begins to conduct, the voltage at point A is limited to VBIAS + 0.7 V so that all input voltage above this level is clipped off.
To limit a voltage to a specified negative level, the diode and bias voltage must be connected as in Below Figure. In this case, the voltage at point A must go below -VBIAS – 0.7 V to forward-bias the diode and initiate limiting action as shown.
By turning the diode around, the positive limiter can be modified to limit the output voltage to the portion of the input voltage waveform above VBIAS – 0.7 V, as shown by the output waveform in Figure (a). Similarly, the negative limiter can be modified to limit the output voltage to the portion of the input voltage waveform below -VBIAS + 0.7 V, as shown by the output waveform in part (b).
Fig a : Clipper Circuit during Positive Half cycle
Fig b : Clipper Circuit during Negative Half cycle
Diode Limiter Application
Many circuits have certain restrictions on the input level to avoid damaging the circuit. For example, almost all digital circuits should not have an input level that exceeds the power supply voltage. An input of a few volts more than this could damage the circuit. To prevent the input from exceeding a specific level, you may see a diode limiter across the input signal path in many digital circuits.
Rotating equipment packages such as pumps, compressors, turbines need the lube oil consoles for their…
This article explains how to blink lights in ladder logic with a detailed explanation video…
In this article, a simple example will teach you the conversion from Boolean algebra to…
In this article, you will learn the PLC cooking timer example for kitchen automation using…
Learn an example PLC program to control a pump based on level sensors using ladder…
In the PLC timer application for security camera recording, when motion is detected then camera…