Fm Generator

29,750

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The internal zener diode on pin 15 of the 4046B provides a stable voltage to the 3140IC operational amplifier. This amplifier modulates the voltage-controlled oscillator (VCO) of the 4046B. The gain of the amplifier is approximately 20 (26 dB voltage). The VCO generates a 220 kHz carrier signal that is frequency modulated. The capacitor C3 can be adjusted to change this frequency.

The 4046B phase-locked loop (PLL) integrates a voltage-controlled oscillator (VCO) and phase comparator, making it suitable for various frequency modulation applications. The internal zener diode on pin 15 serves a crucial role by supplying a consistent reference voltage to the 3140 operational amplifier, ensuring stable operation under varying conditions. This operational amplifier is configured to provide a gain of around 20, equivalent to 26 dB, which is essential for amplifying the input signal before modulation.

The VCO within the 4046B is capable of generating a carrier frequency of 220 kHz, which can be modulated in frequency based on the input signal processed by the 3140 op-amp. The modulation process alters the frequency of the carrier signal in accordance with the input signal's amplitude and frequency characteristics, allowing for efficient transmission of information over radio frequencies.

Capacitor C3 plays a significant role in determining the oscillation frequency of the VCO. By changing the capacitance value of C3, the resonant frequency of the oscillator can be modified, thereby allowing for tuning of the output frequency. This feature provides flexibility in circuit design, enabling the adjustment of the carrier frequency to meet specific application requirements.

Overall, the combination of the 4046B, the 3140 op-amp, and the adjustable capacitor C3 forms a robust frequency modulation circuit capable of generating stable and tunable carrier signals for various electronic communication applications. The internal zener on pin 15 of the 4046B supplies a stable voltage to the 3140IC op amp. This amplifier modulates the 4046B V CO. The amplifier gain is about 20 (26 dB voltage). The VCO produces a 220-kHz carrier that is FM modulated. C3 can be changed to vary this frequency. 🔗 External reference