Mosfet Heating Circuits

[Harvey]

Hi Guruji,

I'm not sure what you have going on there either but any research that you do should be documented as much as possible so we can see how and where it deviates from the norm.

That's what Glen's circuit seemed to do and that's why everyone got excited because it got hotter than expected and ran longer than expected based on the preliminary expectations. It was not until I did the transient analysis here in this thread that I fully grasped how the energy was being moved around and misread. But even then, there does seem to be some extra energy but the tests are inconclusive to pin down the exact details.

As regards running this stuff on an inverter, most of those are quite wasteful and don't usually recommend driving resistive loads. But I did give Glen a drawing of using one 1000W inverter directly on his resistors thus using the FET's in the inverter instead of the heater circuit. But that would be an entirely different setup and completely experimental. One thing that showed clearly however is how the AC and DC are mixed in the CSR reading.

[gadh]

some questions on the setup

Hi Harvey.
i have a question that might show my probes are not so good for the MOSFET heating tests.
please see the images attached.
the upper scale shows the probe when put across the battery or the load resistor. (x100)
the lower scale shows the other probe that is always on the shunt (x10).
why does the lower probe change its waveforms between the two settings ? does the upper one affects the circuit ? is it ok ?
(as you can see i changed my scope to a better one - HP 54645D, digital, 100mhz, 2 ch.)

Another one: i'm currerntly using your modified circuit of the 555, and i have freq. range of about 1.9-3khz (pot's values are 50kohms, 50x2 kohms. the first controls mainly the duty cycle and the latters control mainly the freq.) . if i want to widen the frequency output range of the 555 circuit, which componets are the easiest to change in order to do it and by which values ?

Thanks alot
Gad

[Guruji]

Adding an inverter

What if one add a sort of inverter to the mosfet side or a type of voltage doubler to increase heat instead of many batteries?
Thanks guys.

[Guruji]

Aaron circuit

Hi Harvey or Aaron I was trying the heater circuit of Aaron that had published in the past. For the most of heat giving I adjusted the pots to maximum amps consuming about 1.2amps cause I only have a Multimeter and was heating a bit not that much as a normal heater but good. Don't know what wave freq was going on in it
How many circuits of these should one have to acquire the heat of a gas heater on one filament?
Thanks

[Harvey]

IIRC, the JT uses a flyback oscillation that is dependent on the zener breakdown of the emitter in a bipolar transistor as the trigger.

Here is an example of a 555 triggered HV Flyback:
YouTube - High-Power 555 Flyback Driver

I hope everyone understands that getting HV or High Watts for short periods does not necessarily mean a gain in energy.

[Guruji]

JT

Joule Thief?

The Mosfet Heater circuit and Joule Thief are two completely different systems. The Joule Thief is used to scavenge residual energy from nearly dead batteries at relatively low power values while the Mosfet Heater uses fully charged batteries and high power.

I think it would be bad to try and mix the two technologies at the same time. However, the Joule Thief may be useful in taking several of the batteries that have been run down in the Mosfet Heater application and using what is left in them to recharge one other battery to be used in the future. This would be helpful if you were using some type of battery that required full discharge like Ni-Cad's. Most Lead-Acid batteries do not like to be fully discharged in that way because the lead begins to sulfate rapidly when the electrolyte drops below a certain acidic level. Lead Sulfate crystal is very difficult to get off the plates.

Perhaps the Joule Thief threads could be of more assistance in this regard?

Hi Harvey I know about JT cause I've build alot of them. JT's are a type of voltage amplification too apart that can be used even with dead batteries. From a small 1.5v JT on the secondary can measure 60v or more. This device is useful for many circuits.

[IndianaBoys]

Hi gadh,

After thinking, I have a theory that might explain this.

When you pulse your circuit, a similar dc pulse radiate from the load resistor. Your thermocouple works on the principle of temperature which create an electrical current. However, it sense the dc pulse current and not the current cause by the temperature.

QU

Ferrite Bead may help as shown on page 4 and 5

http://www.phidgets.com/documentation/Tutorials/Addressing_EMI_Issues_Tutorial.pdf

IndianaBoys

[quantumuppercut]

so far no problem. but now i started testing the Ainslie circuit which uses pulsed DC current, and the multimeter shows weird results ! it jumps immediately to 36 degrees (all celsius) (while ambient is 24 deg.) and then almost immediately to 50-70 deg. and continues to fluctuate between these values. the actual water remperature does not change in this time. the probe does not touch the load resistor and the water resistance is between 1-2 megaohms (this value also changes , depending on the scale i choose - 2 mohms, 20mohms, and also by time it changes, so its weird too...).
the distilled water label shows "0 micro-siemens".

could someone help me understand why the heat measuremnt goes crazy ?

Hi gadh,

After thinking, I have a theory that might explain this.

When you pulse your circuit, a similar dc pulse radiate from the load resistor. Your thermocouple works on the principle of temperature which create an electrical current. However, it sense the dc pulse current and not the current cause by the temperature.

QU

[Harvey]

Hi Harvey did anyone tried to do a joule thief on the 24v side and see if heat is increased?
By the way I was reading previous posts did you modify the circuit to better effiency if yes can you please post a schematic of it?
Thanks

Joule Thief?

The Mosfet Heater circuit and Joule Thief are two completely different systems. The Joule Thief is used to scavenge residual energy from nearly dead batteries at relatively low power values while the Mosfet Heater uses fully charged batteries and high power.

I think it would be bad to try and mix the two technologies at the same time. However, the Joule Thief may be useful in taking several of the batteries that have been run down in the Mosfet Heater application and using what is left in them to recharge one other battery to be used in the future. This would be helpful if you were using some type of battery that required full discharge like Ni-Cad's. Most Lead-Acid batteries do not like to be fully discharged in that way because the lead begins to sulfate rapidly when the electrolyte drops below a certain acidic level. Lead Sulfate crystal is very difficult to get off the plates.

Perhaps the Joule Thief threads could be of more assistance in this regard?

[Guruji]

24v side

Hi Harvey did anyone tried to do a joule thief on the 24v side and see if heat is increased?
By the way I was reading previous posts did you modify the circuit to better effiency if yes can you please post a schematic of it?
Thanks

[Harvey]

Hi Harvey yes 20 batteries as you've said but what efficiency is that in consumption. It would be too much for a little heater.
Maybe then one should go more to try that experiment of the two bells in resonance. It is said that that guy acquired great efficiency in heating.
Thanks

We don't know what the consumption would be, that is the whole problem here. We have people in one continent boasting that the consumption is 1/17 that of the thermal output and more, while people in other continents are proving by the proper scientific method that in their configuration the consumption is more than the thermal output. Of course those wild and exotic claims have no data to support them.

Then we have Glen who was guided along to use the wrong method of calculation demonstrating the consumption around 1/6 that of the thermal output.

So who knows, if you use 20 batteries, perhaps the consumption would drop to zero

We need some strong data to prove this stuff conclusively. So far, all of the real data I have analyzed has huge quantities of alternating current in them and no solid means to extract the AC calculations from the DC calculations.

However, I find it very hard to accept that T.H. Moray, Nikola Tesla, N. Stubblefield, Steven Marks and J.B. Schwartz and possibly others, could all be mistaken regarding the large quantities of energy they could extract from the vacuum. Paul Dirac showed that our concepts regarding the EM energy pools must have an unseen counterpart which he called a Sea of Energy and which Moray wrote a book about with that title. So, for me, there seems to be enough evidence that the energy is there, but the method of extraction is not clearly defined.

Therefore, I am hopeful that there is something to this - and if I had the resources I would prove it one way or the other myself.

I should also point out that there is a clear difference between average thermal output in watts and real energy. If I say to you that the MOSFET heater circuit can produce up to 5.4 thousand watts of thermal output that is not the same as saying it will produce 19.44 million joules of thermal energy, which if the output were continuous would be an accurate figure. This circuit is far from continuous and at best adopts a small fraction of the real operation time on the heating element. So let us say we were to get a true 50% duty cycle, we would have to cut the real joules in half. Likewise if it were only 3.7% duty cycle, we would have to cut the real joules down to only 714 thousand even though we would be able to read the true watts at most any instant we measured them because heaters tend to stay hot longer than we can switch them on and off. It would be the same as me turning on a heater until it gets red hot, then turn off the switch and measure the thermal output and current at the same time while it cools down - Zero consumption and a thousand watts of heat for 10 seconds - Yay I think you get the picture.

So in summary, the current methods of Scope measurement are inadequate but I still think there may be an energy pool out there waiting to be tapped.

[Guruji]

Efficiency

Let us suppose that your 1kW heater is rated at 240V, this would give you about 4.1A. So you will need 20 batteries in series to use that heater element with this MOSFET heater circuit, but it should still provide the 1kW you are looking for.

Hi Harvey yes 20 batteries as you've said but what efficiency is that in consumption. It would be too much for a little heater.
Maybe then one should go more to try that experiment of the two bells in resonance. It is said that that guy acquired great efficiency in heating.
Thanks

[Harvey]

Did you try that circuit with a normal 1000w nicrome heater or a water heater?
The thing as I told you before I had build the negative wave circuit with only one 12v battery cause the other circuit needs three 12v batteries.

Let us suppose that your 1kW heater is rated at 240V, this would give you about 4.1A. So you will need 20 batteries in series to use that heater element with this MOSFET heater circuit, but it should still provide the 1kW you are looking for.

[Guruji]

mosfet heater

Wrong.

The circuit will work fine for any normal heater element with a current rating of less than 6A and a voltage rating of less than 1000V. If either of those criteria are exceeded, then the element would not work, otherwise a normal heater element will work fine.

Do you need help with the math and best timing for your normal heating element(s)?

Did you try that circuit with a normal 1000w nicrome heater or a water heater?
The thing as I told you before I had build the negative wave circuit with only one 12v battery cause the other circuit needs three 12v batteries.

[Harvey]

Hi Harvey as I am understanding you rightly so it's impossible to use this circuit for a normal heater element right?
Thanks for response.

Wrong.

The circuit will work fine for any normal heater element with a current rating of less than 6A and a voltage rating of less than 1000V. If either of those criteria are exceeded, then the element would not work, otherwise a normal heater element will work fine.

Do you need help with the math and best timing for your normal heating element(s)?