DIY Dew heater controller

[Richard Wesson]

I am currently in the process of building a controller for dew straps. I have a plastic box to house it in, but the plastic is rather thich making securing the nuts onto threaded stuff securely rather difficult. However, rummaging around, I found a metal box I bought many moons ago for a guitar pedal project and thought of pressing this into service as the metal is thinner and it does look nicer! I am obviously keen to avoid shorts so have used copious amounts of heat shrink. The nagging doubt that I have is that obviously some of the external mount components (power, heater outlet phonos etc) have a metal out  and this connects with the negative leg of inputs and outputs. However, when I think back to the electrics on a car which also runs at 12v DC, this also has negative eathe so this connects to the chassis, so my thinking is it should be OK. However, I would like to have the opinion of others who are more experienced than me to see if I am totally wide of the mark and also if there is anything else I have not considered. 

 

Many thanks in advance. 

[Dr_Ju_ju]

As long as you ensure that all surfaces are at the same potential (usually 0v) then you should have no issues..

[Richard Wesson]

13 hours ago, Dr_Ju_ju said:

As long as you ensure that all surfaces are at the same potential (usually 0v) then you should have no issues..

Thank you for the reply. In laymans terms, I presume that means that there is no leakage from the positive (+12v) side of the circuit to the casing (earth) to where the negative is?

[Dr_Ju_ju]

correct

[Richard Wesson]

Excellent. Thank you so much for your help - it is really appreciated.