12VDC Fan Speed Control Using TC649
Category: Motor Control And Drive
Designer: RANA MUHAMMAD ADNAN KHALIL
Notes
This circuit is designed and simulated in Proteus 8.17 but it can be simulated in any other software. This is a very simple and useful circuit of fan control. 1. TC649 is a fan speed controller IC with auto-shutdown and fan sense feature. 2. This IC is used control temperature of semiconductor devices. 3. Supply voltage range is 3.0V to 5.5V, but fan voltage is independent of TC649 and supports any fan voltage. 4. Fault detection circuit protect against fan failure and aid system testing. 5. This IC supports low cost NTC/PTC thermistors. 6. Temperature proportional speed control is accomplished using pulse width modulation (PWM). 7. A thermistor (or other voltage output temperature sensor) connected to the VIN input furnishes the required control voltage of 1.25V to 2.65V (typical) for 0% to 100% PWM duty cycle. 8. The TC649 automatically suspends fan operation when measured temperature (VIN) is below a user programmed minimum setting (VAS). 9. In normal fan operation, a pulse train is present at SENSE (Pin 5). 10. A missing pulse detector monitors this pin during fan operation. 11. A stalled, open or unconnected fan causes the TC649 to trigger its Start-up Timer once. 12. If the fault persists, the FAULT output goes low, and the device is latched in its shutdown mode. 13. A frequency of 30 Hz is recommended for most applications (CF = 1 µF). 14. Rsense resistor table for fan current control is given in datasheet. 1ohm for 500mA, 1.5ohm for 350mA 2ohm for 250mA, 3ohm for 150mA and 9.1ohm for 50mA. 15. For further understanding, download the files play with them by changing values. Applications: 1. Power supplies termperature / fan control. 2. Gerneral purpose fan speed control. Note: More circuit will also be added soon. Stay connected, if you like effort then share this app with your friends.