# Tagged Questions

How many times something happens per second, measured in Hz (Hertz).

32 views

### Signal encoding on Realtek TX2 IC [part 2]

The image below shows IC Realtek TX2 encoder (pinouts and block diagram), which is part of an RC car transmitter circuit. Datasheet refers: "The frequency of pulse depends on the local oscillator ...
75 views

### 50 Hz antena for monitoring mains frequency fluctuations

I would like to follow fluctuations of the mains frequency (50 Hz, yes, I know they are very low) in the lab without connection to the wall socket. I suppose it should be kind of antenna (capacitive ...
71 views

### Is input impedance of an opamp independent from its input's frequency components?

If input impedance of an op-amp is infinite (theoretically), does frequency of an input signal have any effect on input impedance of the op-amp?
140 views

### Why is mains voltage frequency 60Hz in USA and 50Hz in Europe? [closed]

And what are the consequences in traffic light intensities or flickering?
55 views

### Nyquist sampling rate with real and imaginary aliasing

I need to calculate the Nyquist sampling rate of the function $x(t) = cos(6t)-sin(5t)$. By definition the Nyquist sampling rate is the minimum value of $\omega_s$ that yields no aliasing ...
58 views

221 views

### Whats the principle of a PLL used as demodulator of a FM signal?

I didnt quite understand te following: A basic PLL consists of the following parts: phase detector low pass filter VCO If you input a 1MHz sine the PLL will try to lock on it by controlling the ...