Main filter help

[Lighty]

Hi all

I've connected a Hanna pH Controller device to a mains supply in a room in my home, the problem is there is only one plug point in that room and the interference from 2x 400w Metal Halide if interfering with the pH controller. It works but when it reaches it threshold point the relay starts fluttering, I thought at first it was a hysteresis problem, but when testing with the light turned off it works properly.....

What I need it to filter the interference from the mains before supplying the controller.

I have a old power supply for a HP laptop, could I just use the "pre filter" part of the circuit ( the part before it goes to the rectifying diode) of the circuit to supply the controller, the controller only use a couple watts, +-10w.


Thanks in advance

 

[Lighty]

Anybody that can help?

 

[blueroomelectronics]

You can buy an AC noise filter, probably easier and safer than building one yourself.
**broken link removed**

 

[Lighty]

OK, Thanks Blueroomelectronics, I'll check with one of the local suppliers, but would the filter of the charger not work?