10 led circuit help(white and red)

[sage2605]

Hi.i have a project that has 35 leds (in all) a mix of 16 red-10 white-9 rbg (i have a seperate post for RBG)..so to start the leds are red-2.0-2.2v 20ma..white-3.2-3.4v 20ma..what is the best way to power this many at once without a huge power supply.thank you

 

[KJ6EAD]

You have a total power requirement for all LEDs (including the RGB LEDs) of less than 4W. Even if you double that to accommodate resistor losses, you don't need anything more than a 10W wall wart. A 12V 1A or a 24V 500mA supply would be sufficient.

As to method:
https://www.electronicspoint.com/got-question-driving-leds-t256849.html

 

[sage2605]

You have a total power requirement for all LEDs (including the RGB LEDs) of less than 4W. Even if you double that to accomodate resistor losses, you don't need anything more than a 10W wall wart. A 12V 1A or a 24V 500mA supply would be sufficient.

As to method:
https://www.electronicspoint.com/got-question-driving-leds-t256849.html

well some of the lights will not be on all the time. the white lights will come on when I flip a switch along with the others. what I have to make a different circuit to compensate for some of the lights not being on all of the time. reds and whites come on separately

 

[sage2605]

Can someone help me with rhe circuit.what resistors capacitors to use and such?

 

[(*steve*)]

Can someone help me with rhe circuit.what resistors capacitors to use and such?

Read the post by KJ6EAD above yours...

 

[ICGengineerTech]

LED calculator to figure out your resistor sizes.

And here is another that might help.

~Bill

 

[sage2605]

LED calculator to figure out your resistor sizes.

And here is another that might help.

~Bill

Thank you .ive tried it and it says 12v isent enough for just 10 leds 3v 20ma. what am I doing doing wrong?

 

[ICGengineerTech]

I tried and...

I gave it a try and put in your numbers:

Source Voltage: 12
Diode forward voltage: 3
Diode forward current (mA): 20
Number of LEDs in your array: 10

What I got was a few options for arrays. I might not be understanding the whole problem here. Do you have to have each diode capable of turning on and off independently of each other?

~Bill

 

[duke37]

With 3V/led, three leds = 9V To get 20mA and a voltage drop of the extra 3V, a series resistor R = V/I = 3/0.02 = 150 ohm. The three leds should be connected in series with the resistor.
Three strings will allow nine leds and the current drain will be 3 * 20mA = 60mA

You can work out the resistor if you want to add the odd led.

 

[sage2605]

I gave it a try and put in your numbers:

Source Voltage: 12
Diode forward voltage: 3
Diode forward current (mA): 20
Number of LEDs in your array: 10

What I got was a few options for arrays. I might not be understanding the whole problem here. Do you have to have each diode capable of turning on and off independently of each other?

~Bill

all 10 white leds turn on together but I can cut that to 9 and just add the last one with its own resistor.the RGB leds (9) will all be on at the same time but different colors (no mixes,just basic RGB).The reds (16) will be on only when switched but all wil be on..thank you

 

[sage2605]

With 3V/led, three leds = 9V To get 20mA and a voltage drop of the extra 3V, a series resistor R = V/I = 3/0.02 = 150 ohm. The three leds should be connected in series with the resistor.
Three strings will allow nine leds and the current drain will be 3 * 20mA = 60mA

You can work out the resistor if you want to add the odd led.

Thankyou