Figure 3-49C.Series LR circuit.
There are many ways to generate a trapezoidal waveshape. For example, the rectangular part could
be generated in one circuit, the sawtooth portion in another, and the two combined waveforms in still a
third circuit. A far easier, and less complex, way is to use an RC circuit in combination with a transistor to
generate the trapezoidal waveshape in one stage.
Figure 3-50, view (A), shows the schematic diagram of a trapezoidal generator. The waveshapes for
the circuit are shown in view (B). R1 provides forward bias for Q1 and, without an input gate, Q1
conducts very hard (near saturation), C1 couples the input gate signal to the base of Q1. R2, R3, and C2
form the RC network which forms the trapezoidal wave. The output is taken across R3 and C2.
Figure 3-50A.Trapezoidal waveform generator.