Bandpass filter, voltage and current detection, phase difference detection, temperature calibration, ultrasonic transceiver circuit

QWE4562009

Bandpass filter, voltage and current detection, phase difference detection, temperature calibration, ultrasonic transceiver circuit [Copy link]

I don't understand the principles of these circuits (bandpass filter, voltage and current detection, phase difference detection, temperature calibration, ultrasonic transceiver circuit). Can anyone tell me about them? Let's communicate and make progress together! (I have a poor understanding and am using the dumbest method to learn circuits! They are all related to each other. If you don't like it, please don't criticize me or nag me. Please take a detour)!!!

1. The bandpass circuit is also a frequency selection circuit. Do we need to cascade two sets of op amps to form a bandpass circuit? Can it be realized with one set of op amps?

2. Phase difference detection circuit, two sets of input signals (voltage, current) are directly connected to the two counter pins of the microcontroller. After program analysis, it can be determined which phase is ahead of which and how much the phase difference is? Can the so-called phase be understood as the relationship between the waveform and time in the X-axis dimension?

3. What are the circuit principles of the ultrasonic transceiver circuit and the echo signal amplifier circuit? What are the functions of D2, D3, C19, C20, and R10?

4. The principle of overvoltage and overcurrent detection circuit. I don't understand how to detect voltage and current? It is different from the general connection method.

5. Temperature calibration test, silicone oil beaker, constant temperature water bath, refrigerator (what temperature)? The three layers inside and outside are to prevent the temperature of silicone oil from being affected by the external environment? The last sentence, the tolerance should be ±0.1℃, right? Is it wrong?

申小林

Thanks for sharing, more calculation process would be nice

QWE4562009

Shen Xiaolin posted on 2022-12-28 09:15 Thanks for sharing, it would be nice to have more calculation process

I just can’t calculate it myself...

QWE4562009

Who knows? Looking forward to reply