How to modify brushless esc to use without TX input.

[jason_ices]

I have a project need to convert brushed motor fan to brushless motor fan. The brushed motor is control by build in controller in the mainboard. I was thinking to use cheap brushless combo to done the job, how do i control the speed of the fan by using the brushless esc? HOw to modify the esc to get in input in other way beside pulse code?


Jason

[wjbite]

Well it all depends on how heavy you computer is and how fast you want it to go - assuming that this is a computer fan :)

Seriously, I think you could get the job done pretty easily by finding or making a circuit that is used to put out a signal to test servos. After all, both the ESC and the servo are fed the same waveform to control the speed of the motor or the position of the servo. That signal is about a four volt, positive going square pulse that varies between one and two milliseconds wide and repeats about every 25 milliseconds.
There are lots of servo testers to be purchased and many project web pages that explain how to build them. Some are microcontroller controlled. The simplest are just a good old 555 timer chip with a variable resistor (knob) to control the pulse width. the variable resistor could be temperature sensor (thermistor).

Oh, hey, you could also use a receiver and control it with the joystick on your transmitter. :) [sorry, had to say that[

Try googling it - maybe "r/c servo tester".

Hope this helps.
Walt Bankes

[rumplestilskin]

i think thers is someting to convert input voltage from a rx(like a lama or a blade cx) to run a brushless motor

[jason_ices]

Well it all depends on how heavy you computer is and how fast you want it to go - assuming that this is a computer fan :)

Seriously, I think you could get the job done pretty easily by finding or making a circuit that is used to put out a signal to test servos. After all, both the ESC and the servo are fed the same waveform to control the speed of the motor or the position of the servo. That signal is about a four volt, positive going square pulse that varies between one and two milliseconds wide and repeats about every 25 milliseconds.
There are lots of servo testers to be purchased and many project web pages that explain how to build them. Some are microcontroller controlled. The simplest are just a good old 555 timer chip with a variable resistor (knob) to control the pulse width. the variable resistor could be temperature sensor (thermistor).

Oh, hey, you could also use a receiver and control it with the joystick on your transmitter. :) [sorry, had to say that[

Try googling it - maybe "r/c servo tester".

Hope this helps.
Walt Bankes

Thanks for the help, Walt.

Jason

[AndyKunz]

How about this? The code is easy to modify:

www.rc-hydros.com/pistix.html

They are in stock now - I forgot to fix the date on the website.

Andy