Options DC axial fans and blowers manufacturer NMB
Signal for blockage
The "blockage" function is polled using an additional connection to the fan via the open collector and a pull-up resistor. This signal is automatically reset on restart. Normally a blockage will cause a "HIGH" signal.
(Axial fans with inverted "LOW" blockage signal available on request)
Example of order number: 08025SA-12N-EL-D0
A speed-dependent tachosignal is polled via an additional connection to the fan via the open collector and a pull-up resistor. One rotation causes two impulses.
T1 = = 60/4 x n (n = rotational speed in rpm)
Example of order number: 08025SA-12N-ET-D0
A PWM signal (puls width modulation) with 5 V amplitude is needed to regulate the axial fan speed. Normally the frequency is 25 kHz.
Vst = 0-0,5 V / 0 % rpm
Vst = 4-5 V / up to 100 % rpm
Vst = open / 100 % rpm
The speed regulation is mostly proportional.
(Customized adaptations available on request)