Transistor Multivibrator

Author: Leonard Krugman

Fig. 6-4 (above). Transistor multivibrator.

Figure 6-4 illustrates the transistor equivalent of a basic multivibrator circuit. This configuration is generally useful in the frequency range of 5 to 15 kc. The parameter values shown are for an 8.33 kc oscillator which uses two Raytheon CK720 transistors. The frequency is determined by the R_BC_B time constant. The value of R_B is limited to a maximum of about 200k ohms. C_B is limited to a minimum of .002 μf. The frequency stability is poor compared to the types previously discussed. The output collector waveform is almost a perfect square wave. The advantages of the transistor multivibrator are its simplicity and the small number of components required.