Exploring the Inductive Resistor Heater

[gmeast]

Hi all,

The tests and test protocol I've outlined are based on an academic investigation of a particular mode of energizing an Inductive-Resistor Heater.

I have performed an analysis of the Heater's performance. The analysis DOES NOT rely on the use of expensive test equipment and can be replicated by anyone with the patience and diligence to follow through. A comprehensive testing protocol is outlined at the end of a Video Slide Show I have prepared. The Video Slide Show can be viewed on my YouTube channel at:


http://www.youtube.com/watch?v=q473lX-Zw1w


You must put the following in context AFTER viewing the Video Slide Show. The analysis is of the 2nd circuit configuration below:


The PWM and MOSFET Gate Driver are powered from their own support battery common'd at GND to the circuit being tested. This is to isolate the controlling circuitry from the MOSFET Switch and the Heater Element. Therefore, the PWM and Gate Driver are being treated as sort of a 'friction-less commutator' for the purposes of this investigation. However, it is vital to consider the effect the Driver has on the entire setup. For this reason I performed several tests to determine if the Driver was contributing any appreciable energy in heating the Inductive-Resistor. The tests were performed for two circuit configurations with similar outcomes. Below are the two circuit configurations followed by scope captures showing MINIMAL (if any) contribution from the Gate Driver.

The difference in their voltage drop between Loaded and Not Loaded is 0.9mV across a 0.1 Ohm x 1% non inductive CSR ...SHDriver.  The support battery runs nominally at 13VDC. That translates to 0.117 Watts and for the duration of my tests (8-hours) translates into 0.93W-Hrs of energy.

So ... the contribution from the MOSFET gate driver is negligible, but has been considered against the observed performance of the circuit and noted here. Also, the PWM's input to the Gate Driver is logic level and wouldn't be considered in the scheme of things any more than you'd consider the power a function generator is drawing from its wall socket.

[gmeast]

Hi again,

Just in case someone will want to know what batteries I'm using, I shot some photos of them. I also took a shot of the chargers I use. The larger battery is a SEC1075, 12V, 7Ah AGM (Absorbent Glass Mat) and the smaller one is the SLA0810, 2V, 6Ah, AGM. I use two 12V and one 2V in series. The battery charger is a really cool 6V / 12V Charger, P/N SEM-1562A. I have two of these chargers. One I use for charging the 12V batteries in parallel. The other charger is used to charge the 2V battery, so I have two more 2V to make up the total of 6V, so those charge in series. This is so I can charge both 12Vs & 2V at the same time ... here they are:



Enjoy,


Greg

[picowatt]

Greg,

Is it not more likely that all of your testing has merely proven the well known phenomenon that a lead acid battery, and indeed most battery chemistries, produce different amp hour ratings for different load profiles?  Would you expect a 100% duty cycle 1 amp load, a 50% duty cycle 2 amp load, and a 25% duty cycle 4 amp load, applied to a given battery, to all yield identical amp hour ratings from that battery?

Moreover, with regard to your circuit, and in particular her circuit, the concept of desulphation wherein a continuous sequence of reverse polarity pulses is applied to a lead acid battery to break up large sulphate crystals and enhance battery performance has been around for some time.  Additionally, pulse and reverse pulse plating has been used by electroplaters for years to produce finer grain metallic platings.  As the action of a lead acid battery is also a "plating" process, it is very likely that similar finer grain platng occurs when pulsing or reverse polarity pulsing a lead acid battery while under load, thereby increasing the active area of the plated surfaces and hence, increasing its amp hour rating.

When claims of COP=infinity were beng made, an easy proof would have been to just let the circuit run "forever" to prove the battery never discharged.  Now that the claims are with respect to merely demonstrating that a battery's amp hour rating is increased with respect to a given amount of energy extracted usig different load profiles, one would think that a claim of overunity must also account for and prove that less energy is required to recharge the battery than was witdrawn by the load. 

If you search for desulphator schematics and look at various desulphator waveforms, you will see a great deal of similarity between the operation of those circuits and related waveforms and the circuits and waveforms utilized to produce claimed overunity with lead acid batteries.  But again, I believe these claims are moreso related to claims of increased battery amp hour ratings under varying load profiles in concert with the actions of desulphation and reverse pulse plating than to claims of "overunity".



PW







 

[gmeast]

Greg,

Is it not more likely that all of your testing has merely proven the well known phenomenon that a lead acid battery, and indeed most battery chemistries, produce different amp hour ratings for different load profiles?  Would you expect a 100% duty cycle 1 amp load, a 50% duty cycle 2 amp load, and a 25% duty cycle 4 amp load, applied to a given battery, to all yield identical amp hour ratings from that battery?

Moreover, with regard to your circuit, and in particular her circuit, the concept of desulphation wherein a continuous sequence of reverse polarity pulses is applied to a lead acid battery to break up large sulphate crystals and enhance battery performance has been around for some time.  Additionally, pulse and reverse pulse plating has been used by electroplaters for years to produce finer grain metallic platings.  As the action of a lead acid battery is also a "plating" process, it is very likely that similar finer grain platng occurs when pulsing or reverse polarity pulsing a lead acid battery while under load, thereby increasing the active area of the plated surfaces and hence, increasing its amp hour rating.

When claims of COP=infinity were beng made, an easy proof would have been to just let the circuit run "forever" to prove the battery never discharged.  Now that the claims are with respect to merely demonstrating that a battery's amp hour rating is increased with respect to a given amount of energy extracted usig different load profiles, one would think that a claim of overunity must also account for and prove that less energy is required to recharge the battery than was witdrawn by the load. 

If you search for desulphator schematics and look at various desulphator waveforms, you will see a great deal of similarity between the operation of those circuits and related waveforms and the circuits and waveforms utilized to produce claimed overunity with lead acid batteries.  But again, I believe these claims are moreso related to claims of increased battery amp hour ratings under varying load profiles in concert with the actions of desulphation and reverse pulse plating than to claims of "overunity".


PW

Hi PW,


Thanks for your observations.  Although I'm aware of Rosie's tests that reference Battery ratings, I don't consider the amp-hour ratings of the batteries at all other than to 'range' my load and test duration. In my presentation I do not make any reference to some important data contained in the data sheets ... and that is the 'unloaded' battery voltages. The reason for that data was to compare the start and end voltage differences, loaded and unloaded, and you'll see that those numbers are very nearly the same for any given test. This is a good account of how the batteries drew down ... that is to say ... I was NOT recording 'surface' charge or 'fluff'.  For my batteries, upon unloading, they recover to 95% of their 'new' resting voltage in 2-minutes. That's why I use that figure of 2-minutes (read the testing outline). And also, the times it took to recharge the batteries after the Circuit Test and after the 2nd Draw Down Test were within 45 minutes of one another. After the 1st Draw Down Test, the batteries took a good 3-hours longer to fully recharge.


The test I show in the presentation is a repeat of over a dozen similar tests. And as far as:

" ... Would you expect a 100% duty cycle 1 amp load, a 50% duty cycle 2 amp load, and a 25% duty cycle 4 amp load, applied to a given battery, to all yield identical amp hour ratings from that battery? ... "

I have no idea what you're getting at. I don't use any duty cycle values for any calculation. I'm dealing with equivalent heat in terms of "Energy" ... not power ... using 'power' which is an 'instantaneous component value' is incorrect to use in these analyses.


I used whatever frequency and duty cycle gave me the most heat on the test fixture. It's as simple as that. All I'll say is that I have no idea where the excess heat is coming from but it's there.


My intent for this thread is to post my progress and findings. I will not debate the integrity of the data or my methods with anyone. These tests have been performed many times with consistent results. The batteries always show the same characteristics and show no signs of degradation.


I'm forging ahead on this. Don't attempt to dissuade me because you can't. Thank you,



Greg

[picowatt]

Hi PW,


Thanks for your observations.  Although I'm aware of Rosie's tests that reference Battery ratings, I don't consider the amp-hour ratings of the batteries at all other than to 'range' my load and test duration. In my presentation I do not make any reference to some important data contained in the data sheets ... and that is the 'unloaded' battery voltages. The reason for that data was to compare the start and end voltage differences, loaded and unloaded, and you'll see that those numbers are very nearly the same for any given test. This is a good account of how the batteries drew down ... that is to say ... I was NOT recording 'surface' charge or 'fluff'.  For my batteries, upon unloading, they recover to 95% of their 'new' resting voltage in 2-minutes. That's why I use that figure of 2-minutes (read the testing outline). And also, the times it took to recharge the batteries after the Circuit Test and after the 2nd Draw Down Test were within 45 minutes of one another. After the 1st Draw Down Test, the batteries took a good 3-hours longer to fully recharge.


The test I show in the presentation is a repeat of over a dozen similar tests. And as far as:

" ... Would you expect a 100% duty cycle 1 amp load, a 50% duty cycle 2 amp load, and a 25% duty cycle 4 amp load, applied to a given battery, to all yield identical amp hour ratings from that battery? ... "

I have no idea what you're getting at. I don't use any duty cycle values for any calculation. I'm dealing with equivalent heat in terms of "Energy" ... not power ... using 'power' which is an 'instantaneous component value' is incorrect to use in these analyses.


I used whatever frequency and duty cycle gave me the most heat on the test fixture. It's as simple as that. All I'll say is that I have no idea where the excess heat is coming from but it's there.


My intent for this thread is to post my progress and findings. I will not debate the integrity of the data or my methods with anyone. These tests have been performed many times with consistent results. The batteries always show the same characteristics and show no signs of degradation.


I'm forging ahead on this. Don't attempt to dissuade me because you can't. Thank you,



Greg

Greg,

Not trying to disuade you at all.  Just saying, a battery under different load profiles will net a different amp hour rating and hence, a different discharge curve or rate.

From my read of your test methods, you utilize the differences in battery discharge rates with different load profiles, i.e., a pulsed load of a given duty cycle versus a fixed load of a given resistance to determine efficiency.  So yes, duty cycles, or more specifically, load profiles,  are indeed involved in your tests in that one of your loads is your pulsed circuit at less than 100% duty cycle and your other reference load is a 100% duty cycle load using an equivalent heat output resistor.  Hence, my question, would you expect the same amp hour rating, i.e., discharge rate, from a given battery when loads of 1 amp at 100%, 2 amp at 50% or 4 amp at 25% are applied?  Each of those load profiles would generate the same heat output, but I would not expect the battery to respond equally regarding discharge rates. 


But, please forgive me, I was not aware we were not to post comments here.

PW