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In Reply to: RE: DC voltage drop across choke vs resistor!!! posted by Tre' on March 18, 2017 at 07:29:36
I am not explaining this correctly. The circuit is biased with a diode. This is why I do not check the voltage drop there. So I would normally would check the voltage drop across a choke with known resistance and do the math from there. A buddy told me the choke measurement is not as accurate as a series resistor. So I put a resistor in series and then measured across the resistor and the choke. After the math it was 16 ma for the resistor and 18 ma for the choke.
So everything is constant the diode is setting the bias for the tube the b+ is settled in to what ever the current is. So all I was doing was checking what the measured current is.
So my question is why would the drop across the choke DC resistance measure different than a standard resistor?
"why would the drop across the choke DC resistance measure different than a standard resistor"
It won't. Something else is happening that you're not aware of. As someone else suggested, maybe there's an AC component present.
Buy Chinese. Bury freedom.
That is what I was thinking, in regards to dcr. There are caps to ground in this power supply. Would that cause this measurement issue.
This is only a guess, but there could be some AC ripple riding on the DC ahead of the choke that the choke is blocking and your meter is responding to. Check the voltages with a 'scope and see what you find.
"It is better to remain silent and thought a fool, then speak and remove all doubt." A. Lincoln
I did measure it on the 1st choke in the power supply. There are 2 more will measure there for the fun of it. Should get Closer down the line if ripple is being reduced.
Can the caps to ground cause this issue also?
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