Positive Clipper: The clipper which removes the positive half cycles of the input voltage is called the positive clipper. The positive series clipper circuit (that is, diode in series with the load). while the input is positive, diode D is reverse biased and so the output remains at zero that is, positive half cycle is clipped off. During the negative half cycle of the input, the diode is forward biased and so the negative half cycle appears across the output.