Yes, it is possible to create a phase difference detector for two low-frequency signals using an analog multiplier and a low-pass filter. Here's a general approach to designing such a circuit:
Analog Multiplier:
- Start with two input signals, each representing one of the low-frequency signals you want to compare.
- Feed both signals into an analog multiplier. The multiplier multiplies the instantaneous values of the two signals, resulting in an output signal that represents the product of the two inputs.
- The output of the multiplier will contain the sum and difference frequencies of the two input signals.
Low-Pass Filter:
- Connect a low-pass filter to the output of the analog multiplier. The purpose of the low-pass filter is to extract the difference frequency component from the multiplied output.
- Choose a cutoff frequency for the low-pass filter that allows the desired difference frequency (10Hz-20Hz) to pass through while attenuating higher frequencies.
- The filtered output will represent the phase difference between the two input signals.
Signal Conditioning:
- Depending on your specific requirements, you may need to further process the filtered output signal to obtain a meaningful phase measurement. This could involve additional amplification, scaling, or conversion to a digital representation.
It's worth noting that the accuracy and precision of the phase difference measurement will depend on various factors, such as the quality of the analog multiplier, the characteristics of the low-pass filter, and the overall circuit design. Additionally, the 10Hz-20Hz frequency range poses some challenges due to the low frequency and potential drift or noise. Careful consideration should be given to these factors during the design and implementation process.