Maker Pro
Maker Pro

Best Grounding Scheme For Pwm Electromagnet, Pwm electromagnet digital/analog signals

fernandomierhicks

Mar 5, 2012
4
Joined
Mar 5, 2012
Messages
4
Hi:

I have a setup were I run a electromagnet with a PWM signal using 20 volts, usually at low dutycyles < 20%. PWM frequency in the low kHz range.

Around this electromagnet I have various sensors, cirucits etc.All of this (electromagnet and circuits) is inside a metal chamber (faraday Cage). I need to run some signals outside this chamber, analogue and digital.

The power supplies for the Electromagnet and the other circuitry are ground-isolated.

I want to reduce the noise that the Electromagnet is going to produce on my signals both because of the pulsing and the EM interference.

I was thinking of using coaxial cables for all my signals, using a star scheme once the wires are inside the chamber, so I will have a dedicated ground wire.

Should I also use coaxial cable for the electromagnet leads? Should I ground the shield on this wire to my general "signal ground"?

Should I ground both ends of my signal wires shield?, lets say to the frame?

Any other suggestion recommendation is appreciated, wire types are flexible.

Thanks

Fernando
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Joined
Jan 21, 2010
Messages
25,505
If you use coaxial cable, I think the best bet is to connect the coax shield to the cage where it enters/exits.

On the other hand, you *may* be able to get away with a simple twisted pair.

If your signal level is reasonably high, and the impedance low, you will obviously have less problems than in the reverse case. Understanding the signals is key.
 
Top