Once the sun tracking drive is complete and works well under manual control it is time to add the controller and sensors so the system can automatically track the sun. We have already tested the sun tracking control system and the sun tracking drive so the last thing we have to do before testing is to install the light sensors and shadow gate into the 4x2 test unit mirror support. The wires from the sensors must also be wired from the moving mirror support to the stationary pipe support frame.
First of all this is a test unit so we are building everything so it can be adjusted. We want to make it very easy to move and switch parts and change things so we can test many different configurations to find the best set up for the solar thermal car.
For the LDR (light dependant resistors) sensors I built little pieces of wood that they are installed into so I can move them around and screw them down anywhere on the plywood sheet.
Next I built a large shadow gate (this blocks light to the sensor on the wrong side). I built this with four feet that are screwed into the mirror support. This can also be move around to create the best shadow.
The wires from the sensors must be secured so they don't move around while the mirror is rotating. 4 Small alligator clips are connect to the sensors. These wires are stapled to the plywood and are then rapped around the vertical pipe arm. The are connected to wires that are pushed through holes in this support. These 22 gauge wire pass through second holes in the support so that they do not pull out while the mirror is rotating. There is then a long loop of wire to allow the mirror to rotate to both extremes without pulling on the wires. The wires are then fed through holes in the pipe support frame. The wires can then be connected to the control circuit without them pulling as the mirror rotates.