RANT CAFFE ASYLUM

[picowatt]

EMJ,

I have a pop quiz for you...

A 0.1 ohm resistor is used as a current sensing resistor.  The resistor and its short PCB traces have 10nHy of inductance. 

At a frequency of 1.7MHz, what is the reactance of that 10nHy inductance and what percentage error does that reactance represent with regard to the 0.1 ohm resistance?

PW

[onepower]

v8karlo

I always measure my circuits with
current probe + voltage probe + scope math
and never had any problems.

Not with all complex wave forms and high frequency interference shown in the scope shot EMJ is peddling which is why any professional would laugh there ass off and walk away. The biggest problem is that most people only see the pretty colors and the squiggly lines and assume the electronics are smarter than they are. However a DSO is only as good as the person who knows how to operate it, knows it's limitations and knows what there measuring and seeing.

From what I can see the signal interference is causing errors because there is no way in hell that 7.5 watt bulb is sinking 49 watts, not even 7.5 watts.

Look, I have tested countless FE circuits and been hired to test many others work so when I see preschool stuff like this I tell the people who spent thousands of dollars to hire me were wasting our time here. This is a joke and no rational person would invest there time or money in it to my knowledge. You want to see something which does impress me look at Nelson Rocha's work. A small stand alone self powering circuit with no batteries and the output is self-evident. That's impressive.

Meanwhile EMJ is peddling a ridiculous dog and pony show to impress the weak minded, were better than this in my opinion.

Regards

[EMJunkie]

EMJ,

I have a pop quiz for you...

A 0.1 ohm resistor is used as a current sensing resistor.  The resistor and its short PCB traces have 10nHy of inductance. 

At a frequency of 1.7MHz, what is the reactance of that 10nHy inductance and what percentage error does that reactance represent with regard to the 0.1 ohm resistance?

PW

1.7 MHz is Irrelevant, we do not use frequencies of this magnitude!

I don't understand why others can not take a serious approach? Why so much Silly?

EMJ

[picowatt]

1.7 MHz is Irrelevant, we do not use frequencies of this magnitude!

Have you looked at the scope shots?  There appears to be all kinds of high frequency harmonics and "hash" scattered all over the screen.

If you want to know the frequency content of your waveforms, look up the spectrum/FFT function on the scope and give it a try.

That little box with a frequency readout on the scope does not tell you the frequency content of the observed waveform (unless its a pure sine wave).

PW

[v8karlo]

Why you all adressing to Emj like that video is his work?


It should be Loz work?
And Emj knows about it like it is his own.


Strange.


Partzman already adressed to 0.1 ohm resistor possible pitfall.
Probe 1x, scope 10x.
Any error on 0.1 ohm will be multiplied by 10x on scope, giving all kind of BS.


Why not to use current probe?
With current probe person can not falsify results?


With precision resistors, there is always room for zig zag evasive manuevers,


avoiding the real measurements and possible error. Right?




At the end, why not loop device.
Very simple test, and most convinient.


Why the drama for a week now?