Bathroom Mirror with LEDs and Demister pad - help

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I've read several similar posts on here about bathroom mirrors with LED's and Demister pads, but can't find anything specific to my case, so hoping someone can give me some advice please. I have a new bathroom mirror which comes with and LED Driver inside, connected to LED strips which are 12v, and also a demister pad which runs at mains voltage via a High Voltage Switch.

Both the Demister and the LED's are controlled simultaneously via an IR switch on the underside of the mirror, which you swipe your hand under.

To me, this seems a bit odd, as if the mirror is steamed up, you have to swipe your hand to turn the demist pad on and wait for the glass to clear. Also, both LED's and Demister pad will stay on indefinitely until you swipe your hand underneath a second time to turn them off. The mirror draws around 40W while on, mainly the Demister, so I would rather not risk it being left on and wasting electricity and getting quite hot. Also I imagine we would want the LED's to be on without necessarily having the Demister on.

I don't know if it's possible with this setup, but I wondered if I could split the Demist function away from the LED's, and just have the IR switch control the LED's, as I'm not bothered (as much!) about them being left on. I have a spare Shelly Plus 1PM relay, which I could potentially use for the Demist function, as this could be activated automatically upon the shower turning on, either via a hot water pipe stat feeding the shower, or via a current clamp on the flex going to the shower. I use Home Assistant so can automate turning the Shelly on automatically upon one of these triggers. The thing is, the Shelly seems to have the load switched on the Neutral connection, and because the LED Driver and the Demist pad both share the Neutral, I don't see how I could control the Demist pad separately.

I've attached a wiring diagram of the current standard wiring, and just represented the crimp connectors as Wagos to make it a bit clearer. Can anyone help please?
 

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I'm inclined to suggest - why not turn the entire circuit on and off, via a separate PIR? That should avoid both LED's and the pad being left on.
 
The thing is, the Shelly seems to have the load switched on the Neutral connection
The Shelly doesn't switch the neutral.
The diagram on the Shelly could be a bit confusing - rather than showing what is going on inside the case, it shows what the external connections should be...
Screenshot_20230605-173734_Chrome.jpg

Terminal '0' is the switched live output (connected to a lamp in the diagram).
 
I'm inclined to suggest - why not turn the entire circuit on and off, via a separate PIR? That should avoid both LED's and the pad being left on.
Thanks, I did wonder about a separate PIR, but I was only thinking about a battery powered PIR like my Philips Hue that I use for another automation, as that would still require a smart relay like the Shelly inside the mirror which could be triggered. I would have to have quite a large cooldown period where the Mirror and Demister stay on after movement, as the PIR wouldn't pick up movement while in the shower, which is exactly when the Demister needs to stay on. I suppose I could look at a wired PIR...
 
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The Shelly doesn't switch the neutral.
The diagram on the Shelly could be a bit confusing - rather than showing what is going on inside the case, it shows what the external connections should be...
View attachment 305250
Terminal '0' is the switched live output (connected to a lamp in the diagram).
Ah I see now, thanks for clarifying that. I've since looked at the support docs for the Shelly on their site, which does have an 'internal' view of what is going on:
1685984208493.png


In which case, could I effectively just replace the High Voltage Switch in the current wiring, with the Shelly - with the mains Live/Line into one of the L terminals, and the Live/Line going to the Demist pad from the 'O' switched Live terminal - and connect the Neutrals together including the Shelly? Could the IR sensor then just control the switching of the LED strips?
 

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