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BrianG · 04.06.2007, 03:13 AM

Update to the test results: The overloaded test result is skewed. I forgot my linear supply is only good for ~2-2.5A before the pre-regulated voltage sags to a point that is under the regulated voltage, which will pass a lot of 120Hz AC ripple (120Hz because I'm using a bridge rectifier) riding on the DC voltage. So, that noise on the input can't be good for the switching BEC. I'll probably re-run that test with batteries instead.

The interference surprises me. I don't know about you newe, but MM's radio is 75MHz, which is far above the BEC's switching rate of ~150kHz - a factor of 500 to be exact. Must be something to do with harmonics or something. Even then, I only got ~2.2 millivolts of AC ripple.

If it were me with the interference, I'd shield it with tin foil or some type of metal braid and tie the shield to the ground wire. I guess another feather in the cap for Spektrum! :)

	(#7)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	04.06.2007, 03:13 AM Update to the test results: The overloaded test result is skewed. I forgot my linear supply is only good for ~2-2.5A before the pre-regulated voltage sags to a point that is under the regulated voltage, which will pass a lot of 120Hz AC ripple (120Hz because I'm using a bridge rectifier) riding on the DC voltage. So, that noise on the input can't be good for the switching BEC. I'll probably re-run that test with batteries instead. The interference surprises me. I don't know about you newe, but MM's radio is 75MHz, which is far above the BEC's switching rate of ~150kHz - a factor of 500 to be exact. Must be something to do with harmonics or something. Even then, I only got ~2.2 millivolts of AC ripple. If it were me with the interference, I'd shield it with tin foil or some type of metal braid and tie the shield to the ground wire. I guess another feather in the cap for Spektrum! :)