# Tagged Questions

56 views

### Noise on Proximity switch signal on PLC system

I am working on a PLC based system that uses High Speed counter cards to pick up a signal from a 24 VDC proximity switch. I am having a problem with short duration 10 to 15 volt spikes being seen on ...
94 views

### Thermal noise (Johnson noise)

Let's say there's some 50 ohm resistor connect across the input of some 2 port network that has an input impedance of 50 ohm, so like this: simulate this circuit – Schematic created using ...
51 views

### Why Johnson's noise is not uniform when plotted in log mode?

I have a 2 resistors of 1000 k each , I have connected them in series and biased one end with +9 V and other end with +9 V. The output is taken from connection point of two resistors and I have given ...
220 views

### Low noise, high voltage resistors

What type of resistor technology would be best suited for a voltage divider that must be in the 10+ megaohm range that can work at a voltage of 800V+ across one resistor and have low as possible ...
519 views

### Johnson noise potential divider

A quick question: If I have a potential divider with two 10kΩ resistors, is the noise that you would measure between the two resistors simply the the Johnson noise of a 20kΩ resistor? On a ...