This weekend I mounted the charger, the heater and the vacuum system. The Brusa charger hangs under the same aluminum U bar as the Soliton motor controller. The mount is made of two sturdy 50x50x5 mm aluminum angles with two 3x30mm "suspensions" to distribute the load to all four bolts on the Brusa. It also has a small 2mm diagonal angle to support in in the front to back direction.
The black-faced Brusa charger mounted in front of the transmission
The Brusa high-voltage connected to the connection box.
Still to connect are the control wires the go into the black multi-contact to the right
Angle bar to support the charger front to back
The front battery box serves as the mount point to a lot of stuff in the conversion. The A2 is a fairly modern car and there are no big areas of metal around the engine compartment to mount things on, Only two aluminum frame bars and lots of plastic (which is now removed). So, the vacuum pump is now mounted onto the battery box using two pipe clamps. The vacuum reservoir mounts to the lock carrier in front of the right front wheel where there is some space left. This means that there is almost a meter of vacuum hose (in fact it is coolant hose) between the reservoir and the vacuum servo which is in the rear left of the engine compartment. I hope the hose will not "eat up" all the vacuum by compressing itself.
The vacuum pump mounted on the front battery box
The heater also mounts to the battery box with its top mount. Its bottom mount is an aluminum angle fitted to the box that holds the motor controller.
I am getting second thoughts about the heater. It is made from an ordinary steel pipe and it is far from stainless. A couple of days after I had tested the function and watertightness of the heater I emptied it of the last remaining water. Out came rust-brown water. I am not sure I want to get all that rusty water into the heat exchanger in the ACC even though engine coolant is normally corrosion protective. Maybe I will make a new one out of aluminum instead...
The heater (the black cylinder)
It's a tight space
The wires for the heater goes to the SSR (Solid State Relay) box which will control on/off of the three heating elements as commanded by the Arduino.
More connections go onto the front battery box
The SSRs for the heater...
... connected nicely. Only the control signal from the Arduino remaining.
While I am waiting for the really fun stuff to arrive, the motor, controller, adapter and batteries, I put together an electric brake booster for the car.
In a car with a diesel or gas engine, the engine produces vacuum which is used to boost the brake pressure so that you don't have to press the brake pedal so hard.
When I remove the enging there will be no more vacuum so I have replace that with something else.
So, I built a brake booster from a vacuum pump and vacuum sensor from an Audi A4, an old Sigg bottle that I used to have kerosene in for an outdoor stove, a contactor and the Arduino micro processor.
I use the Sigg bottle because it is red ;) and because it is aluminum. Since the car is made mostly from aluminum I want as much of the parts to be so as well.
The Arduino runs a very simple software the reads the pressure and turns the pump on and off between 600 and 800 mbar of vacuum.
The contactor, which is actually the security contactor that will be used to brake the high current circuit, will be replaced with simpler 12V automotive relay.
Today I tested the my vacuum pump and vacuum sensor. Both pump and sensor are from an Audi A4 and the pump increases the vacuum from the petrol engine when the throttle is fully open and the vacuum is low.
The vacuum pump...
... and the sensor
I connected the pump to the sensor with a vacuum gauge in between. The sensor is fed with a 5V signal and produces a voltage between 0.3 and 4V depending on the vacuum. I used my index finger to block the sensor and produce a varying vacuum in the circuit.
The (chaotic) setup of the vacuum test
It turns out the vacuum pump delivers a max vacuum of 900 mbar and I plan to use it between 600 and 800 mbar with a simple on/off controller.
At 600 mbar the sensor produces a 1.5V signal and at 800 mbar it produces about 0.5V.
So, tomorrow I will build a simple on/off controller with my Arduino computer
