» Shop Filter The Woodpecker

To keep the air cleaner in my workshop, I built two dust filters with two furnace blowers. (here’s the link to my plan) They work really well; but for an optimal performance, I also built a controller to control them.

And it’s on this controller that this document will be focused. Here is the information you need to build and use the applications I programmed to better control the dust filter. It’s a step-by-step document on how to build your own dust filter controller.

Here’s the circuit with all its components but without any external module. I wanted a good controller; not one that simply starts and stops the filter. For that, a simple switch would have been enough. My controller has multiple functionalities. Here are the different modules and their functions:

Adding a RF receiver with a 4 button remote allows you to start the filtration during a period of time set by the time controller, a computer or an Android phone.
The clock module allows you to start the filtration at a set time everyday. (requires communication with a computer or an Android phone)
The Bluetooth module allows you to have bidirectionnal communication to start/stop the filtration and change the values in several menus when it’s connected to a computer or an Android phone.
A second Bluetooth module can communicate with another filter controller. This allows you to have several filtration systems in the same shop which are all controlled by the same ‘‘master’’ module.
The dust detector module automatically starts the filtration when the level of dust is higher than the limit that was set by default. It also allows you to change that limit with Windows or an Android phone.
The optional fan moves the dust in front of the dust detector.

The circuit has a 10 amp relay that activates the motor of the filtration system.

If you don’t use the Bluetooth receiver, the circuit works well, but you don’t have the possibility to update the firmware because it needs the Bluetooth connection to access it.

To better see the electronic diagram, click on the small image on the left.