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Products => Test Equipment => Topic started by: BiOzZ on September 04, 2013, 07:57:31 pm

Title: Equipment for injecting common mode noise?
Post by: BiOzZ on September 04, 2013, 07:57:31 pm

im looking for a piece of equipment i can either buy or make my self that injects common mode noise on to a 60hz 110-120v line for work (power supply designing) but it MUST use an actual sine wave (not like a 4 step, square wave or whatever to make it as real as possible) and it CANNOT inject it down the line because we have other sensitive equipment in the lab and just one 110 and one 220 line

EDIT: oh i need some sort of rough adjustment to see worse and best case scenarios

thanks!

Title: Re: Equipment for injecting common mode noise?
Post by: macboy on September 05, 2013, 06:45:39 pm

How about using a 120V-120V isolation transformer. The secondary will be floating. To introduce common mode noise, connect a suitable noise signal generator between the "low" side of the secondary and ground. You now have common mode noise w.r.t. ground. "Suitable noise signal generator" is up to you.
This should not cause much, if any, noise to be injected back to the source. In any case, you can use a power line filter to help isolate noise in both directions (from and back to the source).

Title: Re: Equipment for injecting common mode noise?
Post by: alm on September 05, 2013, 07:01:55 pm

The signal generator needs to drive the fairly substantial capacitance to ground though. You might need a fairly beefy signal generator or amplifier.