Monday 10 September 2007

The first building blocks of the electrical system are installed.

I installed the first two electrical components recently. In this picture you can see a 20 way fuse block. This had to go in now since it was necessary to install the cowl cheek extension for painting. Power will come from inside the cowl cheek extension.

If a fuse blows I will manage without whatever I loose. Playing with breakers and fuses in the air is pointless.
Under the left hand step, next to the area containing the stick I am installing some electrics. There are three relays and the speed control unit for the trim. I have mounted them on a removable panel so I could ease the task of wiring everything up.

Two of the relays control the trim. Strictly speaking I could drive the trim from the stick switch, but I prefer it this way.

The other relay reads a signal from a micro switch on the flaps. When it senses the flaps are up it pushes the trim power through the speed control unit. Otherwise it bypasses it. I have no manual override, but this way I have one less switch to play with. More time for 'eyes out of the window'.

I really like push on terminals. This is a 12 way unit of pairs of tabs. It will be fully populated (24 connections) when all this comes together, and I am all for simplicity. They are made by Western Electric. I am always surprised they are not more popular.

You can just see the end of a bit of conduit poking through the fore and aft bulkhead. My intent is to use this to take a very few wires through the centre of the bulkhead where the control column passes as a way to get behind the spar.

The relays are Potter & Brumfield part # T9AP5D52. They are easy to buy from any of the big electronics suppliers. The terminal strip is here.

http://www.weco.ca/1_0/1_4/1_4_tech_photo_search.asp?level_id=6

Look at the second item down.