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Does anyone have a 28 LED Diagram Using Photocell & NPN Transistor? Answered

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I am new at electronic engineering but i just have a few questions about a diagram i tested which seems to work, but i rather more opinions to ensure my transistor, or leds, or resistors, or anything else doesn't burn out but last.

Can someone advise me if i need to change any resistors? I need some guidance please. Thank you for the help, its really appreciate. In the future i may be downgrading to 5MM LEDs...Red & White. When i do downgrade, will i need to replace my resistors? MY circuit is in parallel..Should it be a good idea to switch to a Series Circuit instead?

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user
steveastrouk (author)2013-07-27

The all-up running current for the LEDs is 120mA will the transistor handle that ????

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user

i was thinking if it could, but the LEDs manage to work, but i need to make sure the transistor doesn't burn out. Do i need to add a resistor between the transistor and the negative side of the LEDs?

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user

It depends entirely on the transistor, if it can handle the current.

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user

Ok so this looks ok and will work just fine? If i downgrade to 5MM LEDs i would have to switch my resistors correct?

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user

yes. If you have any doubts use an LED calc online.

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