The Open CPAP Project

Affordable Open Hardware CPAP for the masses
Archive for June 2016

Thing starting to move

2016-06-30 by Freemor

After far too long things are starting to move. The project has not been idle all this time. I have been doing a lot of research into various parts trying to find good fits for the project.

I now have a blower (scavenged from an old RemStar Classic (considered an antique these days)). I'll just be using that blower for experimentation. The plan is to find an inexpensive, readily available blower down the road.

The blower in question is a good choice because it is basically just an AC motor. So if I can get things working with it I should be able to use any ac blower of appropriate size.

I've also gotten my hands on a very nice SSR that can be controlled either by potentiometer or PWM to control the speed of the AC motor. The plan now is to use an Arduino to control the SSR via PWM, the SSR will control the speed of the AC blower and thus the pressure.

At this point I'll be using a manometer to check the pressure. In Stage 2 I'll add a pressure sensor to the mix and thus the Arduino should be able to set and maintain the correct pressure without the manometer. Of course pressure will always be verified with the manometer until we are very sure things are working correctly.

Stay tuned! Hopefully there will be news of a successful Stage 1 unit in the next few weeks.