4
votes
1answer
77 views

How do I connect a signal shield to minimise noise from close proximity AC

In my proposed application, I will have approximately 30 RS-485 nodes configured in 3 chains spaced ~1m apart. There is a need to pass through 240v L-N-E, +5v, A, B, GND in each node. The physical ...
1
vote
1answer
121 views

Shared GND on 2 ATX Power Supplies

I'm constructing a custom(cheap) power supply, with digital current meters and such. I'm using 2 ATX power supplies to build it. I'm using 1 for the standard -12, -5, +3.3, +5, +12 outputs. I've ...
7
votes
1answer
169 views

Ground noise and voltage drop problem

I have an RC device powered by a 3.7V poly battery, which includes a motor and a 40KHz sonar. The voltage across the sonar sensor is amplified and then adc-ed. The motor is driven by a 2KHz PWM. When ...
3
votes
2answers
501 views

Power supply noise in audio

I have what is surely a classic problem with regard to power supply switching noise and audio but I am unable to sort myth from reality with regard to what I found so far on the topic. Setup: I ...
10
votes
2answers
1k views

How do you choose an inductor for connecting separate ground planes?

On a board with separate analog and digital ground planes connected at one place, the connection is often made with an inductor. How is this inductor chosen? Obviously it has to be able to handle ...
1
vote
3answers
286 views

Grounding problems

I have a circuit that takes two analog inputs and positions a stepper motor accordingly. The problem I have ran into is the ground has a lot of noise and in turn makes my a/d inputs noisy and then the ...