Testing the vacuum pump and sensor

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