Signal manage (pwm) is input for pwm pulses. Base frequency is 25khz and it's miles applicable from 21khz to 28khz. Enter has ttl stage and consists of pull-up resistor to 5v or to 3.3v in new structures. Sign is not inverted and a hundred pwm method maximal revolutions of fan. Motherboard has open-collector kind output. This construction assure, that with disconnected pwm sign will runs fan with most revolutions.
On the end i write some notes, that fashionable remedy most of 3-twine fan problems. Fashionable become advanced with idea of backward compatibility with 3-twine enthusiasts. Teoretically is possible to apply 4-twine fan like 3-twine at the board with three-twine connector. Vice-versa it is feasible to use vintage 3-cord fan on new board with four-twine header, but with limited opportunity of pwm manage depending on board common sense.
I just were given this laptop fan and it has a three pin connector, i understand the cord with the white stripe is tremendous but how am i able to discover which of the other wires are bad?.
I had in hand fan nidec f09a-12b3s1, which is provided with boxed intel processors. Fan is 86f68e4d402306ad3cd330d005134dac and includes two ball bearings. It is superior made with good balanced airscrew. I tried to nondestructive demounting however i failed, because it's far almost no longer possible. I disassembled it with out harm of electronics. I discover that fan carries tremendously complicated electronics and few integrated circuits which might be unknown to me. Copying of circuit will be very time consument and with out understanding of incorporated circuits almost for nothing. I determined to not reproduction for now.