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

[digitalindustry]

In this thread,only those that can ! show ! what they say to be true will be taken notice of. So your first task is to show Quote: Incandescent bulbs tend to regulate the current flowing thru them.  As more voltage is applied to the bulb and it attempts to draw more current, the temperature of the filament increases, which increases the filaments resistance, which reduces the current flowing thru it.
So i would like you to show us how you can increase the voltage across an incandescent bulb,while maintaining or decreasing the current flowing through it. Show us how you can dissipate more power from an incandescent bulb with less current flowing through it,and dissipate less power with more current flowing through it-->as i have shown.

I have shown the effect in the form of experiment's,and presented those experiments and results by way of video. In this thread,those that choose to argue the point will do so with actual experiments-->(! not text book physics !),and will present there experiment right here on this thread. No credibility will be given here to words without experimental  data to back up there claims.
Words are no longer good enough.

~~~~~


Brad

I agree with this, I want to learn this effect, PW should demonstrate this effect in an experiment as TK did his, otherwise there is a definite credibility gap, as we can say that the effect has been reproduced as TM describes.

after discovering that Pi is not only 'incorrect' but it's also essentially a very inefficient way to calculate (i.e how much human methods seem) i'm sure some people that understand or learned this might be starting to question the reality in which they live?

I'd like to see a simple experiment where:

- an incandescent bulb of this type shines brighter with less or the same current.

note:

(even though bizarrely the last video showed two different currents along the same direct path.)
(however TK experiment reproduced the effect without the CVR did it not? ) (i.e wound R)

ah i'm staring to see the light here the CVR is on the negative, the inductor is the key, of course electrons don't exist, and so called 'electron flow' if this is looked at as a closed magnetic flux system it starts to make more sense.

[EMJunkie]

Hmmm.... I think some people are still missing some points and being distracted by Red Herrings.

1. The current measured by monitoring the voltage drop across the CVR is also the current flowing through the bulb. The elements are in strict series so the same current is flowing through them both. Right?

2. The brightness of the bulb is an indication of the power being dissipated in the bulb. A dimmer bulb means less power dissipated in the bulb, a brighter bulb means more power dissipated in the bulb. This is true regardless of factors like the temperature coefficient of resistance of the bulb, and the duty cycle of pulsation.  Right?

3. The instantaneous power being dissipated in the bulb is Watts=I²R, where I is the current at the instant of measurement and R is the bulb's resistance at that instant. Right? And this is also equivalent to Watts=V²/R, so solving for R we have R=V/I by Ohm's Law. Right?


4. When the capacitor is connected, the current through the bulb is (relatively) constant, so there is no difficulty with the "mean" value of the current. So the power dissipated in the bulb is also constant. The resistance of the bulb can be calculated by R=V/I. We know I from the CVR measurement, but what is V?
Question: Does the voltage drop across the bulb as measured by the scope give us the "V" value for this equation when the voltage is constant, duty cycle 100 percent?

5. When the capacitor is _not_ connected, the current through the bulb is pulsed. So the power being supplied to the bulb is no longer constant. Depending on the thermal lag of the filament, this power is "smeared out" or averaged over some time interval, so the bulb is actually dissipating some power even when the filament is not receiving any current. Hence it can appear to be glowing steadily even though its current supply is pulsed. During the current peaks, as measured by the scope, the power dissipated is related to the _square_ of the current, adjusted somehow for the thermal lag and the temperature coefficient of resistance of the filament. Right?
Question: Is it legitimate to use the simple "mean" value of the current to calculate the average power dissipated by the bulb in this case, since the power supplied during the peaks is related to the square of the current?



Are the Red Herrings starting to jump out of the bucket yet?

A Circuit to study might be a good start:

Tinman, is this Circuit correct? SW1 being the manual Clip lead connection.

   Chris Sykes
       hyiq.org

Lets figure out what's going on...

[EMJunkie]

First thing I noticed is that the Wave Forms are completely different, no sign of any Pulsing:

   Chris Sykes
       hyiq.org

[EMJunkie]

I think if the Circuit is right, and the Scope Shots are an indication, we can see there is a lot less Voltage on the Yellow Trace especially... The Frequency, Rise/Fall time, there, will change the Lights Luminosity.

The total Applied Voltage across the Globe is very much different.

   Chris Sykes
       hyiq.org

[EMJunkie]

Something is wrong with the mean calculation!

At 2 volts per division for the Yellow Trace, its not giving you the right figure.

I agree with what Verpies said:

Yes, incandescent bulbs are not linear but that does not mean that they are not monotonic.
Light bulb's brightness depends on the current flowing through it and Tinman is correct that more current always means more brightness....and in his experiment this is all that matters.

I am more concerned how his scopes calculates the average of these pulses, e.g. from the screen data, from memory or from the waveform period...

   Chris Sykes
       hyiq.org

JOKE: Try DC Coupling.... Hahahaha