this kind of optic fiber is probably only plastic so for a full DIY , you can use also fishing wire with a big power led or an old chistmass tree optic fiber lighted.....
@mfalkvidd said:
I am using them at 12V so the power would be ~4W. Not too much but still enough to get the sink hot!
The voltage makes no difference. 5A is still 5A.
you are right brain fart
The choice of MOSFET can be tricky. Seems that irlz44n was discontinued so you may need to find one adapted to the voltage and current you want to handle.
In all the cases you need to get a logic MOSFET too, meaning that they are fully open usually around 1 to 3V.
Also I'm sort of confused as it seems to me that L7812CV is a Voltage regulator, not a MOSFET. So if you are actually using that in the MOSFET spot it will definitively not work.
Especially if you are handling high current or voltage I would recommend using one from a reputable source for your MOSFET, I recently switched from mouser / digikey / aliexpress to mostly use http://www.arrow.com as you get free regular shipping, event if you order a couple of components (no affiliation to them whatsoever).
I am non technical but I have 8 wirsbo stats in my house. One of them is faulty and the unit is now obsolete. Is it possible to purchase one of these pcbs and use it to replace the one in the faulty stat ?
Thanks
Richard