Pressure activated speed controll

Controlling drill speed with pressure

I have a small hand held drill similar to a Dremel.

I need a way of controlling the speed of the drill while I am using it.

I thought some sort of pressure sensor mounted on the drill would allow me to vary the drill speed without needing an external speed controller.

To achieve this I used a piece of silicone pipe mounted on the drill which leads back to a pressure sensor, connected to a PWM power controller.

The pressure reading is taken by the PIC10F320 and converted to a PWM signal, which is connected to a MOSFET, which drives the drill.

Component choice is down to what I had to hand at the time.