Fermenting chamber build

[chubbytaxman]

Gents,

Planning a fermentation chamber build but I am stuck on the wiring ...
The overall plan includes the following:-

2 x bar fridges (with freezer compartments) - one at each end of the chamber.

http://www.gumtree.com.au/s-ad/archerfield/fridges-freezers/nec-bar-fridge/1058799515

Small self contained fans

http://www.ebay.com.au/itm/150871205699?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Microswitch

http://www.jaycar.com.au/productView.asp?ID=SP0607

2 x Lighting

http://www.jaycar.com.au/productView.asp?ID=ZD0468

and of course power supplies for the above - I reckon 3 or 4 12V ones will do.
These will plug into a power board along with STC-1000's to control the fridge temps.

The aim is to conceal the wiring in the frame as much as possible (to keep the compartment sealed) by using jacks where possible for the external connections.

I am stuck on wiring it up (connections wise) from the micro switch to the lighting.
The idea is that the fans are on when the fridges are cooling, the light comes on (via the micro switch) when the door is open and the fans go off (when door is open). When door is closed, fans resume on/off cycling with the fridge/s and light is off.

Any help appreciated gents.

 

[TheWiggman]

Have you considered 2 microswitches? That's probably the simplest way for an amatuer 'lecko. Have one normally open and the other normally closed, with your 12V items in series.

If you can't find the right switches then a single NO switch using a SPDT relay would be perfect. This one from Jaycar would be suitable.

1. Connect -ve of power supply to both negatives of the fan and light, and teminal 1 on the relay
2. Run -ve of power supply to terminal 3 AND one terminal of your microswitch
3. Run wire from microswitch to terminal 2 on relay
4. Run a wire from terminal 5 to the fan, and terminal 4 to the light

Some dicking around but will be overall neater and only require a single switch. When the door's closed the relay will be powered, running power from 3 > 5 and powering the fan. When the door's open the relay will open, and run power from 3 > 4 and power the light.
It would be better to use a normally closed switch so the relay isn't running all the time. If doing this swap over terminals 4 and 5.

 

[chubbytaxman]

Thanks for the feedback Wiggman, much appreciated.
Just what I was after to get a push in the right direction :super: