Accurate Measurements on pulsed system's harder than you think.

[EMJunkie]

Compared to:

RMS = V_peak * 1/sqrt(2) = 8 * 0.707 = 5.6568V

NOTE: The above Calculation is supposed to be only good for Symmetrical Sine Waves. I realise its not totally correct to use it here. This is just to give some idea of the difference.

Correction: Pk to Pk , not Peak:

RMS = V_{peak to peak} * 1/sqrt(2) = 8 * 0.35355 = 2.8284V

The Globe is seeing a Difference of 8 Volts at a frequency of 68.4 Hz.

   Chris Sykes
       hyiq.org

[tinman]

Verpies & TK

It is good to see some understand as to what it is we are looking at here.

PW
I in no way disagree with what you say about the resistance increasing across the bulb when.the temperature rises on the filament.  What I am saying is the the current flowing through that bulb must increase in order for there to be a temperature rise which causes the rise in resistance.

I am showing a reduction of current flowing through that bulb, but an increase in light and heat output, which means the bulb is dissipating more power. Remember, the voltage also drops across the bulb when the current flowing through it drops-but the dissipated power in the form of heat and light increases.-as TK has also shown, and he is using what you would class as an acceptable CVR.

[EMJunkie]

Verpies & TK

It is good to see some understand as to what it is we are looking at here.

PW
I in no way disagree with what you say about the resistance increasing across the bulb when.the temperature rises on the filament.  What I am saying is the the current flowing through that bulb must increase in order for there to be a temperature rise which causes the rise in resistance.

I am showing a reduction of current flowing through that bulb, but an increase in light and heat output, which means the bulb is dissipating more power. Remember, the voltage also drops across the bulb when the current flowing through it drops-but the dissipated power in the form of heat and light increases.-as TK has also shown, and he is using what you would class as an acceptable CVR.

Yep, I must admit, took me a bit to get it... Little bit of study required.


   Chris Sykes
       hyiq.org

[EMJunkie]

Tinman - Can you scope C2 in run mode and post pic please?

   Chris Sykes
       hyiq.org

[EMJunkie]

On connection of C2 via the Clip Lead (SW1 in the Circuit) this adds a large Capacitive reactance to the Circuit. Its hard to get any data from the screenshots of the scope in the video because the Cap Smooth's out the Pulsing very well!!!

But, this should introduce a Current Lead into the Circuit. Hard to see without more info. This could also be part of the cause of the Higher current seen.

All be it very small as we see mostly DC.

   Chris Sykes
       hyiq.org