My old car has a belt driven fan that spins whenever the engine runs. Not good on gas mileage. I would like to replace it with an electrical fan that runs only when needed.
This is how electric fans are controlled in many cars. A fan control module sits next to the fan. The module is a Normally On MOSFET module. It has an internal 5V source (Normally On), which turns on the MOSFET circuit, which drives the motor. Car computer controls the module with a single wire. This wire is connected to the internal 5V. When the computer grounds it, fan motor stops. The computer generates PWM ground signal based on engine temperature and car speed.
I need to fabricate a circuit that generates PWM ground signal. I found a computer fan control circuit built on TC648 PWM chip. The output pin has 0-5V PWM signal. But this pin can sink up to 45 mA. I need a circuit connected to this pin that can positively pull 5V down to ground. Or do I not? Can someone help me with this?
I have basic understanding of electricity, but not good enough to design an electronic circuit. Thank you. Pulse width is in the order of 10 ms.
This is how electric fans are controlled in many cars. A fan control module sits next to the fan. The module is a Normally On MOSFET module. It has an internal 5V source (Normally On), which turns on the MOSFET circuit, which drives the motor. Car computer controls the module with a single wire. This wire is connected to the internal 5V. When the computer grounds it, fan motor stops. The computer generates PWM ground signal based on engine temperature and car speed.
I need to fabricate a circuit that generates PWM ground signal. I found a computer fan control circuit built on TC648 PWM chip. The output pin has 0-5V PWM signal. But this pin can sink up to 45 mA. I need a circuit connected to this pin that can positively pull 5V down to ground. Or do I not? Can someone help me with this?
I have basic understanding of electricity, but not good enough to design an electronic circuit. Thank you. Pulse width is in the order of 10 ms.
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