arduino / LED circuit knocking out PowerLine Network Adapters

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1

Hi

I have a circuit where an Arduino Nano is controlling a LED Driver IC (TLC59116F) via I2C. Each of the outputs drives a MOSFET that is connected to a 12V RGB LED strip light.

Everything is working fine.

But... (There's always a but, Grins)

When the LED lighting is on my PowerLine Network adapters all drop out and I lose the network.
If I leave the Arduino powered on in the 5V circuit, everything is ok. However with the 12V side on powering the LEDs I lose the PowerLine adapters.

The 5V supply is a 240V AC to 5V 500mA switch mode PSU
The 12V supply is a 240V AC to 12V 20A switch mode PSU

I clearly need some smoothing on the 12V side. But what do people recommend?
Add some smoothing capacitors on the 12V side? If so what size caps?
Or maybe add a low pass RC filter on the 12V, but likewise what values?

The frequency range on the powerline adapters seems to vary based on manufacture, however mine are zyxel adapters.

Any ideas and recommendations???

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2

So you have got the ground of the 12V supply connected to the ground of the 5V supply?

If so can you explain more about what this line means:-

When the LED lighting is on my PowerLine Network adapters all drop out and I lose the network.

What is a PowerLine Network adapter and what do you mean by drop out?

Also how much current does your LED strip take?

3

Try a 1000uF or greater capacitor on the 12V power supply.

But the problem might is most-likely on the 240V side and filtering the 12V output may not help... What happens when you power the LED strips directly without the Arduino & MOSFETs, etc.?

You can't filter the MOSFET-switched PWM power to the LEDs because the MOSFET has to switch quickly.

The solution may be a different 12V power supply. (Or change your network to Wi-Fi. :wink: )

4

The most likley problem is the 240V to 12V 20A supply, is injecting hi frequency noise onto the mains, which is what is killing the powerline adapters.
Have a look at the primary side of the power supply for a filter which is normally a pair of toroids in series with the mains , but before the rectifier bridge.

5

Hi

With the PSU powering the LEDs direct, I.e. no PWM and no MOSFETs the powerline adapters (Zyxel Powerline Adapters) still work.

So I can only assume the MOSFET switching is causing noise.

I'll add the 1000uF to the 12V and report back.

To answer some of the other questions.

  1. Yes the 0V of the 5V side and the 0V of the 12V are together.

  2. The PSU is a 12V 20A similar to this (ebay Link)

  3. PowerLine adapters are Zyxel

  4. When I say the PowerLine Adapters drop out, I mean the can't talk to each other anymore over the mains wiring, assuming because of the noise my circuit is making.

If it is the 240V side...

Recommendations on PSUs?

Or recommendations on a inline plug adapter to filter to go before the main socket.

I tried one of those lawnmower surge protectors but there just a RCD inside and no filter

6

Maybe you could try something as simple as an inexpensive surge protected outlet between the PSU and the mains.

Surge protected power strips are the bane of powerline networks when adaptors are plugged into them, in my experience. Perhaps you can use that to your advantage, to filter troublesome noise from the PSU from flowing back into the mains line.