| 摘要 |
<p>PURPOSE:To obtain the output stable in pulse width, by the series connection of common-base Tr between the load and the collector of the output side transistor Tr of monostable multivibrator consisting of the gate circuit, differentiation circuit and differential inverter. CONSTITUTION:The monostable multivibrator circuit used for the pulse count type FM demodulator is constituted with the time constant circuit consisting of the gate circuit 1 and differentiation circuit 4, and the differential inverter circuit consisting of the constant current source 7 and Tr 5,6. The collector of Tr 6 of this circuit is connected to the load resistor 9 via Tr 15 and it is connected to LPF 12 via the resistor 9. The constant voltage divided with the resistors 13 and 14 is fed to the base of Tr 15 and it is grounded via the capacitor 16. Thus, the voltage between the base and emitter or Tr 15 is constant, the inverse voltage between the collector and base of Tr 6 is always almost constant independently of the presence of the connection of LPF 12 and the output frequency of the circuit 4, and the capacitance between the collector and base of Tr 6 is not fluctuated. Accordingly, the variation in the pulse width is absent and stable pulse width is obtained for the output.</p> |
