| 摘要 |
<p>PURPOSE:To obtain a frequency discriminator which does not change the central potential of the frequency discrimination signal even though the central frequency of the input signal may vary. CONSTITUTION:With supply of frequency set signal 15, the current value of circuit 14 is controlled. Thus, circuit 14 is a constant current circuit in which the current value can be controlled to deliver saw-tooth wave signal 16, and then becomes the constant current source corresponding to signal 15. Signal 17 is the frequency discrimination signal delivered from amplifier 12 and features the waveform as shown in Fig. (c). Here, constant current circuit 14 capable of controlling the current value is used to charge capacitor 6 which generates the saw-tooth wave signals, and then the current value of circuit 14 is controlled by signal 15 varying in accordance with the central frequency of the input signal. As a result, the central potential of signal 17 never change although the central frequency of the input signal may vary.</p> |
