# Charging multiple capacitors in parallel

Discussion in 'Off-Topic' started by smartmachine, Dec 6, 2014.

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1. ### smartmachine Thread Starter New Member

Jun 15, 2013
3
0
Helloos!
I want to ask that, what would be the value in ohms of a resitor to attach with an
LED (Green, 2.1v/20 mAmp.) in series, with a circuit of:
1. 18 capacitors (only) connected in parallel
2. each capacitor is of value 3300 uF/10v
3. all capacitors are electrolytic

* Applied voltage to this circuit is 12v/01 Amp. with a rated charger/adaptor.

The purpose of this question of experiment is:
a) to "see" the charging time of above mentioned capacitor circuit,
b) to observe the phenomena of, when a capacitor (or multiple capacitors) is/are get fully charged, or as
it/they get charged, current stops (or tends to stop) flowing through it/them.

Please also provide description of the calculation of the resistor value with reference to the above.
can also email me on : <SNIP>

Thanks.

Moderators note: removed email to protect you from spambots

2. ### bertus Administrator

Apr 5, 2008
15,805
2,389
Hello,

The capacitors will never be charged as the led is the wrong way around.
The resistor for max 20 mA will be (12 - 2.1) volts / 0.02 Amperes = 495 Ohms.

Bertus

Lundwall_Paul likes this.

Nov 9, 2007
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4. ### smartmachine Thread Starter New Member

Jun 15, 2013
3
0

Helloos!
Yess!... Great Thanks, and you r right! I was mistaken about the diode position to place it wrong way when drawing the circuit. The correct diagram is uploaded here now as above.

1. LED (Green, 2.1v/20 mAmp.)
2. 18 capacitors (only) connected in parallel
3. each capacitor is of value 3300 uF/10v
4. all capacitors are electrolytic

* Applied voltage to this circuit is 12v/01 Amp. with a rated charger/adaptor.

The circuit is practically working, and the LED gets dimmed as the capacitors get charged, but the problem is that, when I connected 08 capacitors out of 10 in parallel, the charging time was visibly around 06 minutes, and when i connected 10 more capacitors of same value as above, I dont see the LED being dimmed for a long period of time (around 25 min.). So i need to ask few more things on it:

1. I dont know exactly the formula/calculation of calculating the charging time collectively when attaching
more capacitors.
2. If I dont have a 495 (or 500) ohms resitors, can I connect 04 or 05 100 ohms resitors in series in place of a
495 or 500 ohms?

Thanks.

5. ### smartmachine Thread Starter New Member

Jun 15, 2013
3
0
Hellooss!
Refering to the circuit just posted, one more thing to ask which i forgot mentioning in the prev. post. It's an experimental small circuit, i know, but the target is, I want to run a 12v d.c motor from this bunch of capacitors (after removing the charging source when the capacitors are fully charged). The mentioned 12vd.c motor attaches a small pully with it to pull another d.c motor of 12v. When the other d.c motor is pulled, its output will be fed back to the bunch of 18 capacitors to remain/retain them charged and hence keep the first motor running.

i know it's a rough abstract of the idea with the mentioned value of capacitors in my prev. post and may not be sufficient to achieve the required, but i will be thankful if you provide/furnish me with the detailed description/guidance of what to do to achieve the above, may be with different capacitor values or different number of capacitors.

It is though obvious that i want to achieve the above with the capacitors connected in parallel, charging them first, and then run a d.c motor with them pullying another d.c motor to give its ouput back to the capacitors to remain them charged! It's a loop!

It would be additionally thaanks, if you could provide a practical circuit/schematic for the above.

Thanking for your cooperation!

6. ### bertus Administrator

Apr 5, 2008
15,805
2,389
killivolt likes this.