Thermal cooling fan controller
A DIY temperature-controlled fan circuit for amateur radio equipment using an LM34 sensor.
Description
The N1HFX thermal cooling fan controller project details a practical circuit designed to manage cooling fan operation based on temperature, a common requirement for high-power amateur radio equipment. This build utilizes a LM34 temperature sensor, providing a linear voltage output directly proportional to Fahrenheit degrees, simplifying the control logic. The circuit's core functionality involves a comparator that activates the fan when a preset temperature threshold is exceeded, ensuring efficient cooling and reducing unnecessary fan noise.
This controller is particularly useful for amplifiers, power supplies, or transceivers that generate significant heat during operation. The design incorporates a TIP120 Darlington transistor to drive the fan, capable of handling up to 5 amps, making it suitable for a range of fan sizes and current requirements. Field results indicate stable temperature regulation, preventing thermal runaway in enclosed environments.
Construction involves readily available components, making it an accessible project for hams looking to optimize their station's thermal management.