MAKE subscriber WidgetNinja writes in to share their first circuit board design, a fan speed controller. This circuit monitors air temperature in a home theater equipment cabinet, and regulates the speed of a fan in order to keep the whole thing cool.
Rather than using a microcontroller and some custom code, this controller is based around the TC649 fan controller from Microchip. A neat feature that this chip incorporates is a fault detection circuit, that will trigger if the fan motor stops working. It’s probably overkill for most projects, however it could come in handy if you are using the fan to protect expensive equipment from being damaged.
Congratulations on your first build, it looks great!