In case you are like me and do not like, after your shower, wiping your bathroom mirror before shaving, this is for you.

I propose a simple way to implement a ""mist eliminator capability" into your bathroom mirror, for a few euros only.

The best mirror for that is made of two parts.

a frame on the wall with the integrated lighting
and the mirror itself, detachable from the frame.

In case you have a mirror made of a single piece you will be obliged to adapt your design to locate the power supply somewhere on the mirror side. However the principle is identical.

Step 1: Components

Heating wire : this is the major component. For a few euros I have found on internet a heating wire made of Constantan, 7,5m long and 2,44 ohm/m (theoretical) resistivity. So the total resistance of this roll should be around 18 ohm. In fact I have measured it around 42 ohm. So the confidence with the internet purchased items is limited.

I have found it on BangGood.

Power supply : for the prototype I have used an old AC transformer extracted from a 12V power supply. For the definitive version I will use a LED driver(see attachment)

To connect these components you will need some cable with soldering skills.

Heating glue : It is the best way to glue the heating wire and to transmit the energy to the mirror at the same time. I have found it on eBay.

Isolating media : Many materials may be used for the isolation function. I have used reinforced tape, very simple to use and efficient.

Connector : In my case necessary to connect the power supply located in the mirror frame and the heating wire glued on the mirror itself, removable from the frame.

Step 2: Schematics

It is very simple. 230V AC => 12V AC or DC => heating wire.

In my case, as the resistance of the wire is higher than expected I have wired it in two halfs in parallel (see schematics), so as to obtain the right power, estimated around 14W under 12V.

The power supply is taken from the 230V feeding the mirror lighting, after the switch.

I have added a connector between the 12V power supply and the heating wire so that it is easy to remove the mirror from its frame.