Nidec UltraFlo™ cooling fans and blowers
V12E Series Adds 24V Fans
to High-Performance Lineup		 New 24V Models for V12E Series

The full scope of high-end performance offered by theUltraFlo®V12E M9 series of cooling fans is now available to 24V applications.

The addition of 10 new 24V vane axial models includes both free-running and feedback-governed, speed-stable versions that span the broad PQ operating range of the popular Nidec 120 x 38mm series. All are offered with a comprehensive array of monitor and control options.

On-line documentation of the expanded V12E series is available here:

Speed-Stable V12E M9 Fans
Free-Running V12E M9 Fans

The design of the basic board is fairly straightforward. The BA6401 motor control IC is used to drive a pair of mosfets in the conventional fashion. Current Limit is implemented by sensing the motor current, Im, by an operational amplifier and reducing the drive to the mosfets if a predetermined level is exceeded. If the voltage across Rsc were to exceed the 0.25 volt level set by the divider connected to the (+) non-inverting input of the current limit amplifier then current limit will be active. A second amp detects the current limit active state and starts an 8 second timer. Should the current limit fault condition persist through the timer period then the motor will be shut down for about 90 seconds. At the end of the 90 second period the motor will restart Vin is the applied voltage at the center tap, 0Volts is the saturated voltage across the switch when ON. 2Vin is the sum of the BEMF (Back Electromotive Force) plus Vin. Vpeak is the voltage clamped by the zeners DA and DB respectively. The zeners clamp the energy that is stored in the inductance of the motor winding. Note that is not the BEMF nor does it have any relationship to the magnet strength or motor speed. The energy is determined solely by the inductance of the motor winding through its magnetic circuit and the instantaneous current in the winding when the associated switch is turned off. The relationship is determined by the formula EJ = (L I2)/ 2 where EJ is Energy in Joules, L is the winding inductance in Henrys and I is the instantaneous current in the winding. The energy multiplied by the frequency of occurrence over the time of measurement yields the power dissipated by the clamp. For example assume a motor operating at 3000 RPM, drawing a current at switch turnoff of 2A, a 1.5 MH winding, and 12 Vin. Turn-off occurs 4 times a revolution, which at 3000 RPM is 50 RPS x 4 = 200 Hz. ((1.5 x 10-3) x (2)2 )/ 2 x 200 Hz = 3 x 10-3 J x 200 Hz = 0.6 Watts. This is a reasonably low number relative to the 24 Watts into the motor. ® UltraFlo is a registered trademark of Nidec Corporation.

Contact! Home Cooling Fans Brushless DC Motors Spindle Motors

UltraFlo T92T UltraFlo 92mm x 25mm dc-powered tube axial fans with the NBRX sleeve bearing system cooling fans computer fans case fans tube axial fans air movers dc fans brushless dc fans fans Nidec Servo fans

Heilind Electronicsis a franchised distributor of Nidec UltraFlo cooling fans and blowers and Nidec Servo fans.