Temperature Controlled Fans

Description

In this demo I'm going show you how you can use the Smart Servo Controller to turn on and off fans with a temperature sensor. The project will use two fans connected to two different relays. The relays will connect to the Smart Servo Controller. An IC temperature sensor is connected to the SSC (Smart Servo Controller). A blinking LED is also connected just for fun.

For more information on the Smart Servo Controller check out the kickstarter campaign here: https://www.kickstarter.com/projects/143152889/smart-servo-controller

Components

1 × Smart Servo Controller My control board that I'm showing off.

1 × MCP9700 Sensors / Temperature, Thermal

2 × Relays Generic 5 volt relays

2 × Diodes Generic diodes for free wheeling

1 × LED A Red LED

Build Instructions

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Step 1

We are going to have the LED blink at about on and off on one second intervals (0.5Hz). Fan 1 will turn on at 46C temperature. Fan 2 will turn on at 60C temperature. To have some hysteresis both fans will turn off at 30C temperature.
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Step 2
Connect the Microchip MCP9700 temperature sensor up to input channel 1 on the smart servo controller.
- Pin 1 is +5v
- Pin 2 is Signal
- Pin 3 is 0V.
- Connect the LED to output channel 1. Add a 0.5K resistor between the LED and 0V. The resistor is to limit current through the LED.
- Connect the relays to outputs 2 and 3. Add free wheeling diodes across the relays to suppress back EMF.
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Step 3
Go to the IO Setup Tab,
- Set the channel 1 input to Analog.
- Set the output channels 1-3 to Outputs. Set the default state to -1 (off). This will keep the output at the current state even when no rules are active.