0 - 10V PWM control

Other Hardware General Electronics
1

I have a small project where I am adding wifi controll to a 160W LED light unit (for my reef fish tank)

The unit is 2 channel controlling white and blue LEDs. They are currently controlled with a potentiometer on the top. This pot is 0v to 10v and I am looking to replace that with a ESP8266 but I am not sure the best way to go about it. I can control the LEDs up to 5v with normal PWM but need to be running the lights at near 10v really.

I figure my options are using a 2n222 transistor to bump the 5v pwm to 10v or using a digital potentiometer. Any input?

2

or using a digital potentiometer.

You need to find a digital pot that can work with voltages above the supply voltage.

using a 2n222 transistor to bump the 5v pwm to 10v

Yes you can do this but you will need a 10V power supply.

3

I just bought a 10v power supply, I have a suitable transistor available. I guess I am asking what the best way to do it is?

I am going to be making a custom PCB for this and want it as simple as possible as I am clearly very inexperienced :o

4

Dimmable LED supplies usually already have a 10volt supply connected to the DIM pin.
You just need to PWM that DIM pin with an open collector (or open drain) circuit.

Connect the 2N2222 collector to DIM-in, and the emitter to DIM ground and ESP ground.
Connect the base via a 1k resistor to the ESP output pin.

Post a link to the LED supply if that doesn't work.
Leo..

5

The driver has a 4 pin ouput with a small potentiometer board connected. Its labeled VDM-, VDM+, V+ and ON/OFF

The V+ is 12 VDC
The ON/OFF is the enable line and needs to be connected to the V+ to turn the driver on.
The VDM- and + is the 10v I need to manipulate with the arduino. :slight_smile:

6

No link to the product?
Or a picture?

Can't you get that 10volt from the 12volt supply with a pull up resistor.
And use the circuit I suggested.

"this pot is 10volt"
How can a passive pot be 10volt.
How is that pot connected.
Leo..

7

This is the driver https://imgur.com/gallery/pdTm8?s=fbm

As its a cheap chinese led unit I can't imagine finding a schematic at all.

Regarding piggybacking the 12v off the driver itself that would be awesome if it could work.

If I am getting me r2/r1+r2 sums correct this circuit would suffice?

[Album] LED Circuit

thanks

8

Use this image guide for posting pictures here.

this circuit would suffice?

No.

Ground of the Arduino must be connected to the ground of your device. In short I don't think the circuit is like anything you need.

9

You should at least post a diagram of that pot board, with parts values.
And/or take clear pictures of it, showing parts values and tracks.
Leo..