Mad Mojo Monkey
- Sep 24, 2015
- 4
- Joined
- Sep 24, 2015
- Messages
- 4
I'm new here. First post. Please advise if this thread is in the wrong place or if there is any problem w.r.t. forum guidelines and rules.
I'm building a variable speed motor controller.
I have a brushless DC motor (12V @ 180 mA). It's a 110 mm computer fan, re-purposed.
I have a DC 19.5V power source.
Desired operational speed is ~30 rpm and up to ~500 rpm. The high end is not so important as the low end.
Additional design parameter to include a switch and an LED power indicator.
I have found many circuit diagrams for designing a PWM using a 555 timer. However, they all stipulate 5V for Vcc.
I imagine that I can use an NPN transistor on the output of the PWM to control the 12V signal to the motor. However, I don't know how to split the voltage to give 5 V to the timer and 12 V to the transistor, allowing for the operation of the LED to be steady on whenever the switch is on.
Thank you in advance for taking the time to help.
I'm building a variable speed motor controller.
I have a brushless DC motor (12V @ 180 mA). It's a 110 mm computer fan, re-purposed.
I have a DC 19.5V power source.
Desired operational speed is ~30 rpm and up to ~500 rpm. The high end is not so important as the low end.
Additional design parameter to include a switch and an LED power indicator.
I have found many circuit diagrams for designing a PWM using a 555 timer. However, they all stipulate 5V for Vcc.
I imagine that I can use an NPN transistor on the output of the PWM to control the 12V signal to the motor. However, I don't know how to split the voltage to give 5 V to the timer and 12 V to the transistor, allowing for the operation of the LED to be steady on whenever the switch is on.
Thank you in advance for taking the time to help.