1-10V Varing Current from an Arduino help!


I am also something of a n00b. I am trying to control some flourescent tubes that dim with a 1-10v analoge input.

I think I am supposed to use a transister to up the five volt arduino output to 10 or 12 but I just can’t understand the diagrams that involve transister interfaces that i’ve found.

Does anyone possibily know how this is done and could lend a hand?

Much appreaciation,


I just can't understand the diagrams that involve transister interfaces that i've found.

So give us a link and say what you don't understand, that way we stand a chance of helping you.

For example;


As far as I understand, the Transistor there is recieving five volts from the top pin, which is being controled be the middle pin and producing an output from the lower pin, which also goes to ground.

If, ignoring the leds in that set up, I produced a changing 1-5v output from the arduino power pin, can i use the Digital out pin to make the transister just double it and connect the emmiter to my lights, which take a 1-10v input?

Sorry if this sounds hopelessly confused, and thanks,


the circuit you have here isn't an amplifier circuit, its a switching circuit. Basicly the LEDs will only go on if you set the digital out pin high.

What you need to do is replace the 5V pin with 10V and then use the digital out pin as a PWM output

can i use the Digital out pin to make the transister just double it and connect the emmiter to my lights, which take a 1-10v input?

Nope: you've only got one 5V supply there, and you can't connect it to itself to double it.

You might be able to get away with connecting 10V instead of 5V to that top pin, taking out the LED, and using the PWM output to control the lights. Probably not, though: you probably need to filter it so it's a fairly steady DC voltage, instead of a series of pulses with an average of 1-10V over time.

Unfortunately, we're still having to guess about this stuff. Do you have a model number for the light dimmers, so we can try to find some documentation on it online?


Thanks for the information and suggestions.

The lights I am dimming are three (coloured) flourescent tubes which are controled by a 1-10v analouge input. The lights will remember the last signal and maintain it until a new signal is recieved so I do not think it must be a constant voltage. Though it can be.

They don't have specs for their analouge systems as I think they are fazing them out but the compant information and their other products can be found here;


I basically want to brighten and dim them in sequence, using three 1-10v currents, to mix red green and blue lights into a full spectrum.

Thank you for your efforts! : )

Remove the LEDs and connect the resistors to a 12V power supply, and connect the ground of this to the ground of the Arduino.

Then take the collector of the transistor and put it through a 1K resistor. The other end of the resistor should go to your lighting input and through a 10uF capacitor to ground.

Then connect the resistor connected to the base to one of the PWN capable Arduino outputs and command it with an AnlogWriite().

Great, that sounds very clear. I'll try this and the others and let you know how I get on.

Thanks again, Nessan