# I have made a flywheel with magnets attached and 4 power coils, not working out properly

#### BobTPH

Joined Jun 5, 2013
8,995
I tried to measure the current without any resistor and bassically there was a pop and carbon was deposited on the choc block connector
That was your capacitors discharging through a short circuit. An ammeter is a basically a short circuit. It is meant to be connected between a power source and a load.

If you want to know the current in a short circuit, connect the ammeter when the generator is not spinning, then start it spinning. You will find that the RPM goes way down, and it will probably produce a fraction of an Amp. This is called the short circuit current, and it is the highest current you will ever see from your generator.

#### Sensacell

Joined Jun 19, 2012
3,451
Let's say your generator puts out 60 volts with no load, (as you stated in the very first post) when you load it with a 220 ohm resistor, the current shows 0.1 A.
What this means is the voltage output is really dropping to 22 Volts.

What THIS means is your generator has a very high source resistance, which means it will not generate much power at all.

#### Sensacell

Joined Jun 19, 2012
3,451
Let's say your generator puts out 60 volts with no load, (as you stated in the very first post) when you load it with a 220 ohm resistor, the current shows 0.1 A.
What this means is the voltage output is really dropping to 22 Volts.

What THIS means is your generator has a very high source resistance, which means it will not generate much power at all.
What are you expecting from this generator?

#### Maglatron

Joined Nov 3, 2023
154
ok so the out put of the coils goes into the capacitor bank through a rectifier that supports the four coils. I measure the voltage accoss the capacitors and it goes up to around 57volts, then I put the resistor in line with the positive line of the capacitor bank (not accross) then I measure the current coming out of the resistor back to the negative line .

#### Maglatron

Joined Nov 3, 2023
154
Let's say your generator puts out 60 volts with no load, (as you stated in the very first post) when you load it with a 220 ohm resistor, the current shows 0.1 A.
What this means is the voltage output is really dropping to 22 Volts.

What THIS means is your generator has a very high source resistance, which means it will not generate much power at all.
What are you expecting from this generator?

ok understood i want to run a 15w motor I want to put the 55v into a custom made inverter made from IR2110 half bridges then when I have 55v ac I will be putting the ac 55v into a 1:4.2 transformer so that it equals approx 240v and then spin a fan over motor for the sake of it. I dont know the input power
ultimatly I want the voltage to only drop to 55v how many volts would I need to put in

#### Sensacell

Joined Jun 19, 2012
3,451
ok so the out put of the coils goes into the capacitor bank through a rectifier that supports the four coils. I measure the voltage accoss the capacitors and it goes up to around 57volts, then I put the resistor in line with the positive line of the capacitor bank (not accross) then I measure the current coming out of the resistor back to the negative line .
So that means you are, in a round about way, measuring the output voltage under a 220 ohm load.

Connect the 220 ohm resistor and measure the total voltage over this resistor, 100 mA through a 220 ohm resistor = 22 Volts.

Open-circuit voltages here will tell you almost nothing about the quality of your generator, measuring with a known load will.

#### Maglatron

Joined Nov 3, 2023
154
So that means you are, in a round about way, measuring the output voltage under a 220 ohm load.

Connect the 220 ohm resistor and measure the total voltage over this resistor, 100 mA through a 220 ohm resistor = 22 Volts.

Open-circuit voltages here will tell you almost nothing about the quality of your generator, measuring with a known load will.
so ok can you give me an example known load can I just use another resistor?
sorry for ignorance I don't understand what you are saying

#### Sensacell

Joined Jun 19, 2012
3,451
Every type of generator has an internal impedance that limits the available power output, be it electrical, magnetic, or mechanical in nature.

From everything you wrote, it sounds like you expect this inverter idea to extract power from your generator that is just not realistically available.

From ohms law, you can calculate the power it's actually generating.

Start with the 220 ohm resistor, next try a 22 ohm, then a 2 ohm.
Find the output power by multiplying the output current by the voltage.
(the output current will be simply be the voltage divided by the resistance value)

You might find a certain value of resistance that gives the most power output, this would then be approximately equal to your generator's internal impedance.
If you are expecting 15 Watts at 220 V, you will need to see maybe 20 - 25 watts at the DC input, as the inverter will have losses.

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#### Maglatron

Joined Nov 3, 2023
154
so you measure the voltage over the resistor and divide by the resistance to get the current and that will match up with the current value that I measure. correct?

#### Sensacell

Joined Jun 19, 2012
3,451
so you measure the voltage over the resistor and divide by the resistance to get the current and that will match up with the current value that I measure. correct?
Yes- it should.

#### Maglatron

Joined Nov 3, 2023
154
so okay I have 2 power resistors one is 220ohm 150watt quite small and the other is 20ohm 500w and massive my thinking was that if I get the resistance to go down then the current will go up the fan oven motor 15watt. so then divide 15 / 240 that equals current of 0.0625amps then multiply by the transformer ratio that equals 0.2625 amps so that is I need to achieve this by my thinking is to lower the resistance untill I reach that number, and of course the voltage after the resistor needs be 55v what are your thoughts. also as I think I mentioned I have another power coil and a considerably larger capacitor bank.

#### Maglatron

Joined Nov 3, 2023
154
so to clarify is the 22 volts over the 220ohm resistor how much voltage is coming out of the resistor, I'm a little confused

#### Sensacell

Joined Jun 19, 2012
3,451
You have zero chance of making 15 watts @ 220 Volts until you can generate at least 20W at the DC input voltage.

The calculation you made makes no sense.

Measure the raw DC output power capability before you bother thinking about anything beyond that.

#### Maglatron

Joined Nov 3, 2023
154
why not? voltage x current equals power
so the power over voltage equals current
and the transformer ratio is 1:4.2 so as the voltage goes up the current goes down by the same ratio
P = V * I

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#### Maglatron

Joined Nov 3, 2023
154
Measure the raw DC output power capability before you bother thinking about anything beyond that.
can you describe how to do that one more time please for to make certain?

#### Alec_t

Joined Sep 17, 2013
14,327
Just measure the voltage V across a resistance R Ohms. The power W in Watts delivered to the resistor is V squared divided by R.

#### Maglatron

Joined Nov 3, 2023
154
top man!

#### MisterBill2

Joined Jan 23, 2018
18,566
One rather fundamental variable with generators is the number of turns of wire that are subject to the variable magnetic flux and the resistance of that wire, So your generator has some number of turns of wire, of some unknown size, in each coil, and as a magnet is passing by there is a pulse of magnetic flux that builds up and then decays. And this pulse then passes through some diodes to e measured across a resistor.
The wire size matters because of the current limiting resistance.
Now for the hard part of the questions: What is the purpose and intent of this amazing assembly of mechanical components?
The effort and expense indicate that it is not just idle activity, but it has some real purpose and intent.
So please explain the application and intent so we can understand more clearly.

#### Maglatron

Joined Nov 3, 2023
154
One rather fundamental variable with generators is the number of turns of wire that are subject to the variable magnetic flux and the resistance of that wire, So your generator has some number of turns of wire, of some unknown size, in each coil, and as a magnet is passing by there is a pulse of magnetic flux that builds up and then decays. And this pulse then passes through some diodes to e measured across a resistor.
The wire size matters because of the current limiting resistance.
Now for the hard part of the questions: What is the purpose and intent of this amazing assembly of mechanical components?
The effort and expense indicate that it is not just idle activity, but it has some real purpose and intent.
So please explain the application and intent so we can understand more clearly.
I want to run the 15watt fan oven motor at full capacity and am finding my route to getting there. heres the transformer I'm using,
I put together 16000uf 100v capacitor bank, and to alter the speed I'm using a 100watt variable light fixture knob, for controlling speed of the motor and I have built a bridge rectifier to accomodate for the four coils each of the coils have a different amount of turns I am also making this inverter because all of the inverters that I have found are for 12v 24v 48v 110v, and the voltage I want to invert is 55-60v!

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#### DC_Kid

Joined Feb 25, 2008
1,072
You made a 3ph delta generator?
From paper to test meters, with expectations you want to realize the math from paper, requires matched components and very tight and accurate geometry.

The 3ph delta can be broken down into three 1ph systems. Test each to see if you they can all output the same thing, then arrange into 3ph delta. It's also important that the diodes be well matched.

As a side note, would a Y config be better?