Stop in for a cup of coffee
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dukeboy440
Well-Known Member
LOL, I was not going to comment on this electrical stuff even if I am an electrician. It is like opening a can of worms.
It is always difficult to explain things with English as a second language, then to explain things in a way so it is easy for everyone to understand is not easy at all, no matter what language.
I like to think of electricity as water in a hose. High tension I compare to High pressure in the hose, the inner diameter of the hose as the resistance, and the amount of water that flows through is the current.
The higher the water pressure, the more water or current can go through the same hose. The bigger the hose, the more water can flow through with the same pressure.
Now, here is something confusing for a lot of people.
Tension is usually represented by the letter U, but some use V. It is measured in Volt, represented by the letter V.
Current is represented by the letter I, it is measured in Ampere, (or Amps), represented by the letter A.
Resistance is represented by the letter R, and is measured in Ohm, which is represented by the Omega sign, Ω
Now, when it comes to resistance, this is just half the truth. This is for direct current. For alternating current, the following should be used.
Impedance is represented by the letter Z, but also measured in Ohm.
Now, to take the last first, a coil, either it is a coil for a spark plug, or the coil in a motor, transformer or electric magnet for example, are always impedance, or Z. And here is what happens, to explain it in a bit simple way. When the current tries to rush in a coil the coil creates a magnetic field. This field is giving resistance to the current since you also can create electricity from magnetism.
But, once the magnetism the coil is making has reached it's maximum level for that particular coil and voltage, the current will continue to flow through the coil wire at a steady rate and it is then the direct current resistance properties in the wire that also gives the resistance and based on the voltage gives the amps through the wire.
Now, if you break the circuit, the coil will send a current the other way in the coil until it is magnetically discharged and no more current goes through it. Then when you connect the circuit again the same will happen again. So, during the time the magnetic field builds up, the resistance in the coil is not the normal resistance, it is impedance and has a different value than the pure wire resistance.
An example of this circuit will be a coil for the spark plugs in a car.
The same applies for the coil if it is connected to alternating current, for example in the house. The voltage will raise up to it's top value, and then go down again, cross the mid line of the sinus curve, and go the other way in the wire for the next half period of the generator full turn (if a two pole generator). The coil gives "impedance" to the circuit, based on the frequency. The higher the frequency, a given coil will have a higher impedance and the lower the frequency the lower the impedance, all the way down to 0 frequency when the impedance figure will be identical to the resistance figure.
To take this to cars, the ohm's that is measured in the primary circuit of the coil can not be used for calculating how much current goes through the coil. Then, as the engine spins faster, the frequency also increases and therefor the impedance (ac-resistance if you will), and the lower the current will be. So, the most current will go through the coil at idle, and the least current will go through at maximum speed. This also means that the most powerful spark comes at start and idle, and the least powerful spark will come at maximum rpm. This is also the reason the coil can burn if the engine stops and the ign. switch is not turned off, if the engine happen to stop with the points closed so the coil draws full current, and now the coil is just a resistor and the absolutely maximum current flows through it.
Now to light bulbs.
All incandescent light bulbs use tungsten (Wolfram) as the resistance material in the filament. And tungsten increases it's resistance as the temperature goes up. So, it is self regulating sort of.
Resistivity of Tungsten - The Physics Factbook
Unfortunately the chart above does not explain the different letters that is used, but at least it is possible to see that the resistance goes up with higher temperatures.
As for how much amps that goes through a light bulb, that depends on the resistance in the filament and the voltage at the ends of the filament.
The voltage measured at the car battery is always higher than at any of the "users" or "consumers" if you like. As soon as the voltage is led through a wire, or a connection, you loose voltage. A little here and a little there. Thicker wires has less resistance, (lower ohm), and you will loose less voltage. Thinner wires the opposite.
As soon as voltage is lost, from for example 12 volt to 11.99 volt, that one hundreds of a volt is causing a temperature increase in the wire it goes through. If you want to calculate it, you can measure the amp through the circuit, multiplied with 0.01 volt, and then you get the wattage.
And watt is the same as power, which is represented with the letter P, and is measured in Watts, represented by the letter W.
Then, let us assume you have a circuit, you have a battery, then you have 4 pieces of wire, different gauge, and different length, then you have a light bulb, and 4 pieces of wire back to the battery, also with different sizes and lenghts. No matter where in this circuit you measure, the current will be exactly the same. No difference at all. If someone manage to measure different currents in all the 8 pieces of wire, and the light bulb, either the amp meter is wrong, or you have done something wrong, like not having equally good contact to the wires. I still say, no matter where in the circuit, you have the same current. But, if you measure the voltage over each piece of wire, and over the light bulb, well, that is an entire different matter. Those figures will not be the same (at least not in this example).
And, the voltage multiplied with the current will tell you how much power (in watts) you have in each piece of wire and connections, and how much power the light bulb gives.
Now, I think this is enough for tonight.
Bill
It is always difficult to explain things with English as a second language, then to explain things in a way so it is easy for everyone to understand is not easy at all, no matter what language.
I like to think of electricity as water in a hose. High tension I compare to High pressure in the hose, the inner diameter of the hose as the resistance, and the amount of water that flows through is the current.
The higher the water pressure, the more water or current can go through the same hose. The bigger the hose, the more water can flow through with the same pressure.
Now, here is something confusing for a lot of people.
Tension is usually represented by the letter U, but some use V. It is measured in Volt, represented by the letter V.
Current is represented by the letter I, it is measured in Ampere, (or Amps), represented by the letter A.
Resistance is represented by the letter R, and is measured in Ohm, which is represented by the Omega sign, Ω
Now, when it comes to resistance, this is just half the truth. This is for direct current. For alternating current, the following should be used.
Impedance is represented by the letter Z, but also measured in Ohm.
Now, to take the last first, a coil, either it is a coil for a spark plug, or the coil in a motor, transformer or electric magnet for example, are always impedance, or Z. And here is what happens, to explain it in a bit simple way. When the current tries to rush in a coil the coil creates a magnetic field. This field is giving resistance to the current since you also can create electricity from magnetism.
But, once the magnetism the coil is making has reached it's maximum level for that particular coil and voltage, the current will continue to flow through the coil wire at a steady rate and it is then the direct current resistance properties in the wire that also gives the resistance and based on the voltage gives the amps through the wire.
Now, if you break the circuit, the coil will send a current the other way in the coil until it is magnetically discharged and no more current goes through it. Then when you connect the circuit again the same will happen again. So, during the time the magnetic field builds up, the resistance in the coil is not the normal resistance, it is impedance and has a different value than the pure wire resistance.
An example of this circuit will be a coil for the spark plugs in a car.
The same applies for the coil if it is connected to alternating current, for example in the house. The voltage will raise up to it's top value, and then go down again, cross the mid line of the sinus curve, and go the other way in the wire for the next half period of the generator full turn (if a two pole generator). The coil gives "impedance" to the circuit, based on the frequency. The higher the frequency, a given coil will have a higher impedance and the lower the frequency the lower the impedance, all the way down to 0 frequency when the impedance figure will be identical to the resistance figure.
To take this to cars, the ohm's that is measured in the primary circuit of the coil can not be used for calculating how much current goes through the coil. Then, as the engine spins faster, the frequency also increases and therefor the impedance (ac-resistance if you will), and the lower the current will be. So, the most current will go through the coil at idle, and the least current will go through at maximum speed. This also means that the most powerful spark comes at start and idle, and the least powerful spark will come at maximum rpm. This is also the reason the coil can burn if the engine stops and the ign. switch is not turned off, if the engine happen to stop with the points closed so the coil draws full current, and now the coil is just a resistor and the absolutely maximum current flows through it.
Now to light bulbs.
All incandescent light bulbs use tungsten (Wolfram) as the resistance material in the filament. And tungsten increases it's resistance as the temperature goes up. So, it is self regulating sort of.
Resistivity of Tungsten - The Physics Factbook
Unfortunately the chart above does not explain the different letters that is used, but at least it is possible to see that the resistance goes up with higher temperatures.
As for how much amps that goes through a light bulb, that depends on the resistance in the filament and the voltage at the ends of the filament.
The voltage measured at the car battery is always higher than at any of the "users" or "consumers" if you like. As soon as the voltage is led through a wire, or a connection, you loose voltage. A little here and a little there. Thicker wires has less resistance, (lower ohm), and you will loose less voltage. Thinner wires the opposite.
As soon as voltage is lost, from for example 12 volt to 11.99 volt, that one hundreds of a volt is causing a temperature increase in the wire it goes through. If you want to calculate it, you can measure the amp through the circuit, multiplied with 0.01 volt, and then you get the wattage.
And watt is the same as power, which is represented with the letter P, and is measured in Watts, represented by the letter W.
Then, let us assume you have a circuit, you have a battery, then you have 4 pieces of wire, different gauge, and different length, then you have a light bulb, and 4 pieces of wire back to the battery, also with different sizes and lenghts. No matter where in this circuit you measure, the current will be exactly the same. No difference at all. If someone manage to measure different currents in all the 8 pieces of wire, and the light bulb, either the amp meter is wrong, or you have done something wrong, like not having equally good contact to the wires. I still say, no matter where in the circuit, you have the same current. But, if you measure the voltage over each piece of wire, and over the light bulb, well, that is an entire different matter. Those figures will not be the same (at least not in this example).
And, the voltage multiplied with the current will tell you how much power (in watts) you have in each piece of wire and connections, and how much power the light bulb gives.
Now, I think this is enough for tonight.
Bill
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Hello Night Owls
Howdy
Hard at work tonight Stephen ?
Lynyrd Skynyrd-The Ballad of Curtis Loew
Not too bad. Got a little maintenance to do. How are you this evening?
Up for a bit here, slept for a while after super so up now.
I hear ya.
Simple Man - Lynyrd Skynyrd
Cool Scenery Pictures in this Video !!!!
Cool Scenery Pictures in this Video !!!!
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Man uses drone to find stranded animals in Bahamas
This dog looks pretty content, but got to be a mess out there yet. Rescuer just gave this dog some food and water.
This dog looks pretty content, but got to be a mess out there yet. Rescuer just gave this dog some food and water.
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Thanks for the tunes!
Night Photo
Autumn Colors
Mornin.
Hey Rob
Morning
hey George! Guess your GII, there is another one on here also. and three Mikes!
Two Dusters Cruising
Possibly a Scamp ???
Definitely not a nova!
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