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Topic: High output variable voltage (Read 1 time) previous topic - next topic

Solid

Hello.

I have a question about a project that I am starting.

What I have
5 meters of led strip (http://www.sparkfun.com/products/10260)
14.4V power supply
Arduino

What I need
I want to let the arduino to set 0-12V (variable voltage) to each R/G/B wire, by using external power supply.
Because the whole chain takes 6000 mA @ 12.0V

What I know
The PWM ports can only output 0-5V, and 60 mA per channel.

Can anybody direct me to the right direction, which components are best here?
Linear Regulators, Shift Register or what.

What is the easiest way?

PaulS

Quote
What I know
The PWM ports can only output 0-5V, and 60 mA per channel.

You might want to check this fact. The recommended upper limit is usually 40mA, with 20mA being recommended for long term use.

You can use a transistor to control each leg. Transistors can toggle at PWM speeds, and can control that amount of current.

AWOL

Quote
The PWM ports can only output 0-5V

sp. "The PWM ports can only output 0 or 5V"
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Solid

Whoops... thanks for the correction.

so a PWM pin set to 50% duty cycle, connected to transistor and external power supply, should give me 50% brightness on led strip ?

How do you hook up an transistor to external power supply?

JimboZA


How do you hook up an transistor to external power supply?


.... like this
No PMs for help please. Not active on this forum any more.

Solid

Can these transistors, like BC546, hold up to 2A@12V ?

the datasheet says 100 mA / 500 mW.

Any other solution ?

JimboZA

You'll need to look at the datasheets for various transistors...
No PMs for help please. Not active on this forum any more.

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