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Capacitor discharge in pulses - Questions

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Ok guys,

Basically I want to light a light bulb using only the energy from a capacitor.

Just name the size of your capacitor ... ( so to get worthy answers )
Plus ,no matter what your plan is , some things are impossible to work ...

There is no cow that does coco-milk !!
 
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Sorry, I was going to post the circuit and the data. But I spent more time than I thought.

Basically, I want to light a little 12V light bulb. The common connection would be to connect the bulb directly to the power source. But in this case, I want to light it using the energy stored in a capacitor.
In the first operation, the power source is connected to the capacitor while the bulb is not conected to the capacitor.
Then, the capacitor is disconnected from the power source and then the light bulb is connected to the capacitor. The operation is repeated again and again.

**broken link removed**

The circuit only represents the intention, I mean that the final circuit will be switched automatically, using transistors and probrarly a IC 555.
I don't know the value of the cap. But I think it need to be around 20Volts, non polarized. I don't know the uF.

For those that say that It's not possible to light an incasdescent light bulb with a single capacitor charge, here is the evidence that it's possible.

Check around 5:20
https://www.youtube.com/watch?v=wRWwFxNZZxc&feature=related

The capacitor is 200 Volts, 330 uF.


Here you have a simple (incomplete and non-finished) schematic of what I mean.
The transistor of the left side allows to flow current to charge the capacitor. When the capacitor is charged up to 12 Volts (because the light bulb is 12 Volts), then the transistor of the right allows to flow electricity from the capacitor to the light bulb, while the capacitor is not connected to the main power source.

Maybe I would need to used a PNP and a NPN transistor. When the 555 pin 3, sends a positive pulse then the NPN transistor allows the flow of current from battery to the capacitor. When the pin 3 of the 555 is at 0 volts, the PNP transistor allows the flow of current from capacitor to the light bulb.

**broken link removed**
 
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Well I wish you good luck on this experimental project.

But your main difficulty are that capacitors are unable to supply Amperes.

From my point of view , the important its not to light the bulb, but the produced light to be usable for something.

Keep on, your experiments , at list you will have some fun ...
 
I saw the low current but high voltage light bulb light for a moment. So what? What good is blinking a light bulb only one time?

The guy in the video has two magnets that are doing nothing. He says he is making sparks so his "probe" is simply applying power to the transformer's coil each time he sparks it. Then the transformer steps up the voltage.
 
I read somewhere in this thread that it would be very difficult to light a light bulb with the energy stored in the capacitor. Someone said that using only 1 cycle/charge of the cap it won't be enough to light the bulb because the bulb doesn't lights instantly, it needs a little of time to light. With that video I wanted to show that only one charge of the cap is enough to light an incandescent bulb. Only just that.
 
I read somewhere in this thread that it would be very difficult to light a light bulb with the energy stored in the capacitor. Someone said that using only 1 cycle/charge of the cap it won't be enough to light the bulb because the bulb doesn't lights instantly, it needs a little of time to light. With that video I wanted to show that only one charge of the cap is enough to light an incandescent bulb. Only just that.
Power equals voltage times current. The capacitor was charged to a very high voltage so it had enough power to blink the low current light bulb.

Try lighting a 12V car headlight with a capacitor. The lightbulb might blink if the capacitor is 47F (Farads!).
 
Thanks for the information,
I have a question for you and all. Imagine I have a 200 Volts 330 uF capacitor. I know if I charge the capacitor up to 200 Volts, then the cap can draw energy for A units of time. I mean, bigger capacitance = more time flowing energy from the cap.

In an hypothetic case, I charge the cap only up to 40 Volts, then... the capacitance will be affected? I know the capacitance will be always 330 uF. But my question is simple: charging the cap up to 200 Volts the cap will draw energy for a finite time (related with the capacitance of the cap). But If I charge the cap only to 40 Volts.. The cap will draw energy also for the same time as if I would charge it up to 200 Volts?
I know if will draw less energy because if I charge the cap up to 40 volts it won't have the same energy if I charge it up to 200 Volts. But my question is if it will draw energy for the same time. If the discharge time will be the same (because in both cases the capacitance is the same).
I don't know if I have explained well the question.
 
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The capacitance are the dimensions of one warehouse ...

The capacitor's "Max operational voltage" = How strong are the walls of the warehouse.

The capacitance can be presented also as cubic square meters ... of space ..
You can store rocks in cubic square meter or cotton , the upcome are still an cubic square meter.

Other than rocks & cotton , you can also store energy ... no matter the voltage ,
you will continue to have one cubic square meter of energy..

You cannot control the capacitor by the way that you are thinking.

Still you can do an experiment , get an 15.000 mF at 50V ,
charge it with 3.3V and connect to it an LED , and monitor the current draw.
One LED needs 20mA max .
If you got that 20mA then the capacitor has the ability to handle the specific current .

Yes .. yes you need to light up an 12V bulb , well if you use an 0.5W one , its possible to light up , but there is no clear answer of what capacitance you need for it .

You should find the bulb first , and then test with 1000mF and if its not enough, the add more capacitors in parallel .
And also forget those capacitors with out polarity , those have very little mF,
and they are used as filters in crossovers for 2 way speakers .
 
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