Ok,so now you have my attention Pm
Below is a pic of my setup,and the schematic to go with it.
I decided to give the 1n4007s a go as my diode array,and larger capacitor values to try and get the frequency down.
Well seems i have achieved that,as the frequency is down to just 27.9KHz
The wave forms on the scope are very clean,but making the calculations from the scope is going to be trick,as some of the forward voltage is being recycled through the transformer,and so average cannot be used to make the calculation.
In the schematic,you will see i have added another CVR on the front end,as i had my suspicions that the CVR in position 2 (CVR 2) would not be giving the correct information to use as the current CVR.
The wave form across CVR1 is very different to that of CVR 2.
For my P/in calculations i have used CVR1.
In saying all that,i think we must be missing something here,as my COP is very high
P/in(tonight) was calculated by using my DMMs,as at this low frequency they are very accurate.
V/in was taken by placing the DMM across the primary of L1.
I/In was taken by placing the DMM across CVR1,and measuring the voltage. Then current was calculated using ohms law.
The scope shows(oddly enough)that the voltage and current are dead in phase,and so the power factor is 1
Both DMMs are a different brand,and both show the same voltage readings across CVR 1 and the primary of L1
Scope was used to confirm measurements.
So P/in was calculated to be--
I/in=165mV across 10 ohms=16.5mA
V/in=165mV across L1 primary.
Scope average did not agree with DMM in this case--something to look into there.
Scope gave an average voltage of 355mVYes,oddly enough the voltage across the primary was the same as the voltage across CVR1
So P/in =2.722mW
P/out is 26.2v over the 15k resistor.
The voltage across R1 C1 was taken with my DMM and scope. Both agree with each other.
P/out=45.762mW
Apparently the COP is 1681%-->!!Apparently!!
I find it hard to believe that both DMMs would be out the very same amount.
My top end DMM has been used many times,and is accurate with pulsed DC far above the frequency being used here.
!BUT! something is not right some where?
What we need is to brainstorm the most accurate way to calculate P/in.
P/out is no problem,as it is smoothed DC across a known resistance.
I will be doing the long hours on this tomorrow night for sure.
Brad
Added
I am driving the circuit with my SG.
Never let your schooling get in the way of your education.
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Topic: Parametric Charging (Read 61371 times)
