Is this circuit possible? And what resistor should I use?

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Hi all,
I am a new member here.

I am quite new to making circuits,etc. and have decided to make something easy-ish on a breadboard. I have included a diagram of what I am planning to make. I am using 6x white
LEDs and a 9v battery. I was wondering what resistor I should use for
this? Also, is this even possible? Do I have enough power to light up 6 LEDs not full power
, as I know i don't have enough power for that, but even just a little bit bright? Would really appreciate
any help on this. apologies for bad grammar, am in a rush!

Thanks, Jamie
Ireland
 
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  • Photo of a breadboard with a 9 volt Panasonic battery connected at the top rail, six red jump wires, six white LEDs and resistors wired in parallel rows, labelled JUMP WIRE, LED x6, RESISTOR (but what kind).
    circuit..jpg
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Hey there Jamie
welcome to PF

1k resistors ( as currently shown) would be OK as a starting point, then increase or decrease a little to get the brightness you want

Make sure you have the LED's the right way around :smile:Dave
 
White LEDs drop a forward voltage of about 3.3V.

Each LED will have (9V – 3.3V) / 1kR = 5.7 mA. I would have expected Ifwd to be closer to a typical 20 mA.
For 20 mA you would use R = (9V – 3.3V) / 20 mA = 285 ohms, use standard value 270R.
Total current will be 6 chains * 21.1 mA = 126.6 mA.

You can save energy by wiring LEDs in series pairs. Then for 20 mA LED current you need a series;
R = (9V – 3.3V – 3.3V) / 20mA = 120 ohms, a standard value.
Total current will be I = 3 chains * 20 mA = 60 mA.
So the battery should last twice as long.
 
Thank you for a quick reply:) This helps a lot!
One more question though, can I use normal wire instead of using breadboard jumper cable wires?
I have "normal" wire so if I could use it it would save having to buy the jumper cables.

Thanks again,Jamie