Bedini SSG measurements

[MileHigh]

Hi BiDaDiKuNuKu,

A "True RMS" multimeter is a slightly more expensive multimeter that can measure the RMS voltage of an arbitrary voltage waveform.  In other words the AC waveform does not have to be a sine wave.  That's in contrast with an ordinary multimeter that can only measure the RMS voltage of a perfect sine wave, like from your AC mains power.

The voltage output waveform from your generator coil setup will not be a perfect sine wave.  Therefore to measure your power output you need a multimeter with true RMS capabilities.  "RMS" meas "root mean square," it factors in the fact that higher voltages deliver proportionally much more power to the load than lower voltages.

So like to really meassure it properly, one should take in account the times pulsed for each revolution and also the time of each pulse duration.

Yes, and even the pulse itself itself has an irregular waveform.  Therefore the waveform for the current consumption from a Bedini motor is highly unusual, pulses mixed with zero consumption, and the pulses themselves are irregular.  It's sometimes simply impossible for a multimeter to convert this into an equivalent average DC current consumption.  Therefore you use "tricks" with a large capacitor and a shunt resistor to overcome this problem.

Example, if u got like 3 magnetes to pulse on a cirkel of 5cm diameter (5x3.14=15.7 cm) and the 3 magnetes are like (example 1/5 of that toatal(15.7cm)..
Does this means that u only pulsed for 1/5 of each revolution... so if 1 revolution is 100 % so 1/5 is like 20% pulsed...

That's correct but you are oversimplifying how much time the pulses are on, you cannot make a correspondence with the physical size of the magnet.  You can look at this on a scope to have a better idea.  All that you have to do is put a 1-ohm shunt resistor in series with your power supply positive and then you will be able to see the current pulses by looking at the waveform across the shunt resistor.

How can one convert that 20% amp draw into the "genuine" amp draw.

The "genuine" amp draw is the real-time amp draw.  It is not convenient to work with this data.  Therefore with the capacitor/resistor setup we have discussed you can say that the genuine amp draw is equivalent to a certain average DC amp draw.  This is a perfectly valid thing to do.  Once we have the equivalent average DC amp draw, and we already know the voltage, then we can calculate the average power consumption of the motor.

The whole idea is that it is not convenient to work with the "real" pulsing data, it's too complicated.  We have to work with the averaged data, otherwise we would go nuts.

MileHigh

[BiDaDiKuNuKu]

@ MileHigh...
Thanks for the input, much appriciated...
May u all have a great week & be safe...

Peace!

[MileHigh]

Some more issues related to Bedini motor measurement techniques.

Getting to Know Your Drive Coil

Certainly you want to take your multimeter and measure the resistance of your drive coil.  Assuming that your source battery is 12.6 volts, then you can determine the approximate amount of current that your drive coil can draw from the source battery after the voltage has been applied long enough to fully energize the inductance of the coil.  I am saying that the current is "approximate" because it is in fact a little bit less than this because when the transistor is ON, it's not a perfect switch.  For most transistors, you might see a 0.2 volt drop across the transistor when it is on.

So with your approximate drive coil current you can look up the spec sheet for the transistor you are using and see what base current is required to fully turn the transistor 100% ON.  This is reference information for doing a test on the drive coil and also for when you want to get to know your pick-up coil.

I am assuming that a typical drive coil is between 8 and 20 ohms.  We want to look at the current flowing through the drive coil and in most cases we would use a 1-ohm current sensing resistor in series with the drive coil to do this.  That's a little bit too close for comfort to 8 ohms, therefore I would recommend that you take two 1-ohm resistors and put them in parallel to make a 0.5-ohm current sensing resistor.  That should be a low enough resistance to not affect the operation of the drive coil too much.

The next thing to do is do a reality check test.  Remove the charging battery from the Bedini motor and leave the reverse-biased diode in place connected across the two terminals of the drive coil.  That diode will protect the transistor and protect you from getting a high-voltage shock.  Connect the 0.5-ohm current sensing resistor between the source battery positive terminal and the coil.  Disconnect the pick-up coil connection from the transistor base.  You are now going to switch the transistor ON and OFF just by using the 12.6 volts from the source battery.  Therefore you need to calculate the correct base resistance to give you the proper base current that will switch the transistor on completely when the resistance is connected to 12.6 volts.

So now you are ready to do the reality check test.  Switch on the transistor completely by connecting the base resistor to the positive terminal of the source battery.  With your multimeter check the voltage at the collector of the transistor.  It should be about 0.2 volts above ground.  This would be telling you that the transistor is 100% ON, which is what you want.  If it is higher than that then don't be surprised if your transistor starts to heat up fairly quickly.  This would be indicating that the transistor is not 100% ON and is instead operating in partial conduction mode.  You need to fix this problem by lowering the base resistance to increase the base current.

Since you know the voltage of the source battery, the voltage drop across the transistor when it is 100% ON, the resistance of the coil and the resistance of the current sensing resistor, you can easily calculate the current through the coil.  Then put your multimeter across the current sensing resistor and measure the voltage.  Calculate the current from the voltage measurement and see if it is about the same as what you calculated the current should be.  If everything checks out, you are good to go!

Now you can put your Bedini motor back together but leave the current sensing resistor in place.  Run the Bedini motor and look at the current through the drive coil by monitoring the voltage across the current sensing resistor.  Try playing with your base resistor, see what happens as the motor gets up to full speed, etc, etc.

When your motor is running at its normal speed, you will be able to see the coil energize and then discharge it's stored energy into the charging battery.  All of that information is in the current waveform of the drive coil.

You will notice that the famous "voltage spike" is not too glamorous looking when you look at the current waveform.  You will simply see the current drop to zero when the transistor switches off.  Again, it is not a "voltage spike" coming out of the drive coil, it is a "current spike" and it is worthwhile looking at it.

If you replace the charging battery with different resistances, you will see the L/R time-constant change as you change resistances.  The higher the resistance the shorter the L/R time-constant.  This is a rough analogy to an old sulfated charging battery.  The lower the resistance the longer the L/R time constant.  This is a rough analogy to a fresh battery.  The longer the time-constant the higher the average current going through the diode into the resistance.  Again, this illustrates that the average output current from the discharging drive coil is VARIABLE and dependent on the input impedance of the charging battery.

The most important thing you are looking for is to check how much current is flowing through the drive coil before the transistor switches off.  The current is at a maximum just before the transistor switches off.  The closer this is to the maximum current that can flow through the coil as per your calculations and measurements above, the less efficient your Bedini motor will be for converting source battery power into charging battery power.  This is because of the law of diminishing returns with respect to the drive coil:  The closer you are to saturating the drive coil to its maximum current level, the more energy you are loosing in the drive coil due to resistive losses.  Also, the rate of increase in current spike energy decreases the closer you get to saturating the coil.

Finally, now that you know what your transistor collector voltage is supposed to be when the transistor is 100% ON, you can also monitor the transistor collector voltage with your scope while the motor is running.  Looking at this voltage will tell you how well a job your pick-up coil setup is doing at switching the transistor 100% ON or 100% OFF.  That is your goal for the pick-up coil circuit, to operate the transistor as a switching device only, and to avoid putting the transistor into partial conduction mode as much as possible.

MileHigh

[Plengo]

Status update:

Today I got my 4 bedini coils. Transistors are on the way. Rig to hold the whole setup done.

Fausto.

[MileHigh]

Fausto:

It looks great!  It looks like you are building a "four-cylinder" engine there.  I am sure that you are having fun!

MileHigh

[Plengo]

Status update:

Today I got the 50 transistor MJL21194. Now I have almost everything to build. I will manufacture the board myself and mount the coils very soon.


And yes, it is fun. Almost like a 4 cylinder engine.

Fausto.

[MileHigh]

Getting to Know Your Pick-Up Coil

The pick-up coil is what is used for timing the firing of the transistor.  It does this by putting current through the base of the transistor.  There is a trimpot or a fixed resistance to limit the current going into the base input of the transistor and also adjust the timing of the switching of the transistor.

We can think of a few design goals for the pick-up coil and transistor setup:

We want it to turn the transistor ON and OFF as quickly as possible so that the transistor only works in switching mode.
We want it to use the least amount of energy as possible in order to keep any Lenz' Law drag on the rotor to a minimum.
We want to have flexible timing so that we can tune our Bedini motor.

There are a lot of trade-offs that can come into play here.  For example, if you make your pick-up coil a lot of turns, then you can get higher voltages out of it.  That coupled with a higher base resistance will give you faster OFF-ON and ON-OFF switching times.  The trade-off is that you burn more energy in the pick-up coil circuit and therefore cause more Lenz' Law drag on the rotor.

My advice would be that once you get your motor running, spend a day or two experimenting with different pick-up coil and base resistance combinations.  This has to be done with an oscilloscope, and what you want to look at is the transistor collector voltage.  As mentioned in a previous posting, looking at the collector voltage tells you how well your transistor is switching.

One of the limitations associated with a standard pick-up coil configuration is that you are pretty much limited to switching on the transistor at top-dead-center (TDC).  If you really had a choice, it would be nice if you could delay the start of the pulse to sometime past TDC, because at TDC you are not getting any torque out of the repulsion between the magnet on the rotor and the electromagnet of the drive coil.

Personally, I am not a fan of doing a full bifilar winding of the entire coil so that you end up with two identical coils, and you use one for the drive coil and the other for the pick-up coil.  I think that it would be worth it to experiment with a smaller pick-up coil made with fewer turns of wire that is close to the rotor.  I believe that this type of configuration would give you better overall performance and control over the timing circuit for your Bedini motor.  A small pick-up coil will most likely work much better than a full-sized pick-up coil.

If you want to experiment with different pick-up coil configurations, you must understand how the pick-up coil interacts with the changing flux with respect to time due to the passing rotor magnets.  The smaller and simpler the pick-up coil, the faster the rise and fall times will be in the voltage waveform generated by the coil.  This can be advantageous because it facilitates faster switching of the transistor.

Another interesting idea would be to use a two-stage transistor amplifier setup to power the drive coil.  The pick-up coil output would connect to the base resistance of the first transistor.  This base resistance could be very high and therefore it would not really load the drive coil at all.  The first transistor output would provide the appropriate base current to the second transistor, which is the transistor that energizes the drive coil.  That extra signal amplification would facilitate very fast transistor switching, which is what you want.  Since the base resistance of the first transistor would be very high, it would effectively mean that you are just reading the EMF from the pick-up coil, like in a comparitor circuit.  That could make the variable timing setup much easier to do.

Anyway, there are many interesting possibilities that a Bedini experimenter could explore for the pick-up coil timing circuit.  I would recommend that you get your Bedini motor running with a standard pick-up coil setup first.  Then after that perhaps explore other options with your pick-up coil circuit to see if you can get better performance from the pick-up coil circuit and from the motor.  There are ways to get much more flexible timing if you have a totally separate pick-up coil also.

MileHigh

[BiDaDiKuNuKu]

Status update:

Today I got my 4 bedini coils. Transistors are on the way. Rig to hold the whole setup done.

Fausto.

Looking good Plengo ...keep at it

[ion]

There are ways to get much more flexible timing if you have a totally separate pick-up coil also.

I would opt for Hall effect sensor driving FET or Darlington in place of the pickup coil. They are available with built in low power hysteresis amplifier for nice clean transitions to drive the power device.

Also a small separate Hall effect device allows easy timing adjustment.

http://www.allegromicro.com/en/Products/Design/hall-effect-sensor-ic-applications-guide/#Q7

[MileHigh]

Well I stumbled across a new YouTube Bedini SSG clip that's quite interesting.

http://www.youtube.com/watch?v=gPpfO_yinr4

Efinder2 has a setup where his SSG is running in self-oscillation mode.  The SSG output is charging a cap, and that is powering a quite large DC motor.  When he uses his fingers to put a load on the large DC motor, he sees that his SSG current consumption goes down.

So, as of today this clip is one week old and some other SSG enthusiasts are congratulating Efinder2.  The exciting thing is that when he adds a load to the DC motor the current consumption goes down.  It sounds very impressive, and it seems counter-intuitive.  So the preliminary conclusion is that it looks like some Bedini SSG magic is happening, more load equals less current.

I made three postings on his clip suggesting that he make some more measurements to try and understand what is going on.  I think I know what's happening and I outlined that in my postings.  It remains to be seen if he will make more measurements.

MileHigh

[MileHigh]

I'm going to discuss a measurement issue that came up from Aaron's comments in the Bedini 10-coiler thread on EF.

Fist Aaron said these correct comments about using voltage on batteries as a way of determining if you have over unity or not:

That is a tired and worn out argument. Those that know what
they're doing do not simply use voltage that shows up on a meter
to see how much energy there is. Work is drawn from the battery.

This has been repeated countless times and insinuating that this
is the method used to determine "overunity" is misleading and is
manipulation. Some people starting out will think voltage readings
means more than it does, I did in the beginning because I didn't
know better but this does NOT apply to those that have been
working on these projects for a while.

Then subsequent to that he made these comments:

Then turn off the machine and disconnect the secondary battery and
draw a load at the right rate (c20 is probably what most people will
scream about) and also with a current sensing resistor and do the same
data capture until that battery is down to the voltage where it was
before it received a charge. Use a resistive load on this battery instead
of an inductive load.

Aaron is suggesting this:

1.  Measure the start charging battery voltage.
2.  Measure how much energy you put into the charging battery
3.  Discharge the charging battery at the C20 rate and measure the energy until the voltage reaches the voltage you measured in Step 1.
4.  Compare the energy you put into the charging battery from Step 2 and compare that to how much energy you extracted from the battery in Step 3 to determine your COP.

The huge mistake here is that Aaron is using battery voltage, which is what he stated that you can't use in a posting that he made just one day before.  I also am pretty sure that the Yahoo Bedini groups use the same method and that means all of their COP data is junk.

Here are the facts to consider:

A.  The voltage on a battery is essentially the same for up to 90% of the discharge cycle.  That simple fact right there indicates that measuring battery voltages is meaningless data.
B.  When you charge a battery you will read a fake voltage that is higher than the real battery voltage due to the battery's charging input impedance.
C.  When you discharge a battery you will read a fake voltage that is lower than the real battery voltage due to the battery's discharging output impedance.  Depending on the discharge rate, you will read a different voltage.

The whole premise for Aaron and the Yahoo Bedini group's COP measurement for charging and discharging batteries is hopelessly flawed.  You simply cannot pick an arbitrary battery voltage and charge and then discharge back to the same voltage.  Logically it doesn't make any sense at all.  Even the ambient temperature will affect the nominal battery voltage.

Somewhere in this thread or in the 10-coiler thread there is a discussion about how to make measurements to determine how much energy there is in a battery using load testing.  You have to define a protocol for a given battery and stick to it.  It's a lot of work and it takes discipline.

And I will repeat a comment that I have made before.  Measuring the output impedance of a battery can tell you about the state of charge of the battery or the state of health of the battery.  It is much more useful information than the open-circuit battery voltage.  Experimenter's should learn how to do this so that they can get a better handle on their batteries.  It has been mentioned several times by me and nobody ever says anything.  It's a very useful tool and it is simply not discussed by the experimenters and I think that's a shame.

MileHigh

[BEP]

I never make a comment when you make this argument because the only comment must be, "You are correct".

When I see a group using such COP determinations, I don't waste any more time reading the posts.

[muDped]

=> DeepCut

Have you yet visited the lead acid battery desulfation forum?

HERE

Pulse charging is very beneficial to several battery chemistries
but especially so for the lead acid battery.

The brief over-voltage spikes are very effective at converting
old crystalline sulfate back into active plate material to restore
battery capacity.  They will also accomplish equalization without
excessive gassing and heating of the battery.

The main reason these kinds of chargers aren't sold as a retail
unit by big names is their production of EMI/RFI.

Several repetitions of the pulse charging followed by useful
discharge cycle will restore your batteries to their maximum
capacity.  Converting all of the accumulated sulfation on the
plates is a rather slow process and does take some time.

Yes, pulse charging (when done carefully) is superior to steady
state charging.

Please continue with your accounting of your progress.  It will
be helpful to all who desire to get the most out of their lead acid
batteries for the longest possible time.

[DragonSlayer]

Hi MileHigh,

I've been busy but have also taken some to read up on the stuff you suggested. My 3 pole Bedini motor is on it's way so I have preparing to do some testing and was reading up.

I have some questions I hope you can answer. You must have built heaps of these Bedini motors to know so much about them.

If the coil is only charging to the run battery voltage how is it that the charge battery voltage can get higher than the run battery voltage?

There was a post where the guy asked why his neon bulb lights up when it is an AC bulb. How can it do this if the run battery is only say 12v and it takes 90v to light the bulb?

I don't know what you mean about Lenz law and how it fits with Bedini motor? I thought that Lenz law means that the collapse in the coil stops the wheel turning but I've seen videos that show that the magnet is past the wheel when the coil switches off?

In the Yahoo group they to charge the battery to like 14.5v and discharge it to like 12.2v and measure the current to the battery. But you have to do the same for 20 runs. This makes sense to me. Why do you say this is junk? I don't know how to measure battery impedance, do I need fancy instrument or scope or something?

DragonSlayer