Novice fixing motion switching LED bathroom mirror

Thread Starter

Dysonco

Joined Dec 30, 2018
2
Hi All,

First visit and first post, so hello and I hope everyone has had a great Christmas!

I'm hoping general discussion is the right place to start for my query?

We've had an LED lit and heated bathroom mirror my wife purchased from Ebay many years ago that has never worked correctly. The motion sensor continually activates the relay so it would constantly turn on and off (possibly partly due to the ceiling down light reflecting off the white sink back up into the sensor). Our long term fix has basically just been a bit of paper taped over the sensor so it doesn't activate at all. Major downside being its then just an expensive normal mirror... Minor down side being if we have a power cut or have to turn the particular power circuit off, it comes back in the on state and we then have the fun of trying to remove the paper wave hand to turn it off and get paper back in place before it turns back on again.

So today in post christmas boredom I decided to crack it open and see if there was a way I could replace the motion sensor with a simple switch instead, on opening it up it appears that the motion sensor is basically a IR LED and a light sensor, so 3 wires to the LED and two wires to the sensor, with my little knowledge I wondered if shorting the two wire coming of the sensor would activate the relay switching the LED light and heating circuit, unfortunately this isn't the case.

Bathroom mirror.jpg

The current setup is based on https://www.cens.com/cens/html/en/product/product_main_114109.html and I'm wondering if there's a simple relay or direct switch I could put in its place instead? The output from the above goes to both a heating element on the back of the mirror glass as well as to an LED driver that drives the LEDs. So I'm guessing a simple waterproof switch and relay would be a straight forward way of replacing the never working motion sensor?
20181230_142148.jpg
I have a great deal of experience with computer builds but not really electronics and wondered if anyone could suggest what might work here? I do appreciate given this is a bathroom mirror and water and electricity means I have to be sensible, the whole unit is sealed and any switch I install will need to be a waterproof switch.

Any advice much appreciated!

Best wishes,

Mike

P.S. I should point out I'm in the UK, so 240V mains power.
 

dl324

Joined Mar 30, 2015
11,930
Welcome to AAC!

If it were me, I'd figure out what was causing the false triggering and deal with that.

If it's an IR sensor, it detects heat, not reflected light. If there's no sensitivity adjustment, you can make the sensor less sensitive by putting a filter over the sensor and/or blocking part of the detector.
 

killivolt

Joined Jan 10, 2010
789
Hi All,
Minor down side being if we have a power cut or have to turn the particular power circuit off, it comes back in the on state and we then have the fun of trying to remove the paper wave hand to turn it off and get paper back in place before it turns back on again.

Any advice much appreciated!

Best wishes,

Mike

P.S. I should point out I'm in the UK, so 240V mains power.
If it were me I would just wire a switch to the Mains, that way it isn't coming on until you say it does, so it will come one in the on state, when you're finished switch it off or if you know how long you'll be in the room, put it on a timer switch that counts down to off.

kv
 

Thread Starter

Dysonco

Joined Dec 30, 2018
2
Many thanks for the replies all!

@ dl324, I have tried various things to get the motion sensor working correctly, there's no adjustment and using something to filter it just means if it's filtered so it isn't automatically triggering, then it only works one in ten swipes. Just a badly designed I think, hence why I'm thinking plan B

@killivolt The mirror also has a shaver socket which I use for my shaver charger, so I don't want to switch the whole thing, just the lighting and demist function.

All I want is either a water safe power switch I can build into the unit or safer i guess would be a relay to switch the power via a momentary switch? The switch location would need to be on the lower edge so being waterproof is a must as it's only about 30 cm above the basin. Problem is I'm not even sure what I should be searching for to do this ;-/

Any further advice much appreciated!

Mike
 
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