In a PARALLEL LIMITER, a resistor and diode are connected in series with the input signal. The
output is taken across the diode.
In the PARALLEL-POSITIVE LIMITER, the positive portion of the input signal is limited when
the diode conducts.
The PARALLEL-NEGATIVE LIMITER diode is reversed from that of the parallel positive
limiter to limit only a portion of the negative input signal.
The DUAL-DIODE LIMITER combines the parallel negative limiter with negative bias (reverse
bias) and the parallel positive limiter with positive bias (reverse bias). It will remove parts of the positive
and negative input signal.