The next type of diode limiter to be discussed is the dual-diode limiter, shown in the figure below, view A. This limiter combines a parallel-negative limiter with negative bias (D1 and V1) and a parallel-positive limiter with positive bias (D2 and V2). Parts of both the positive and negative alternations are removed in this circuit. Each battery aids the reverse bias of the diode in its circuit; the circuit has no current flow with no input signal. When the input signal is below the value of the biasing batteries, both D1 and D2 are reverse biased. With D1 and D2 reverse biased, the output follows the input. When the input signal becomes more positive than +10 volts (view B), D2 conducts and limits the output to +10 volts. When the input signal becomes more negative than -10 volts, D1 conducts and limits the output to this value. When neither diode conducts, the output follows the input waveform.