Koford Engineering (Winchester, OH) offers the S24V30A sensorless motor driver with 37 kHz pwm frequency for use with standalone, digital, or analog operation. The drive has no minimum inductance and will operate slotless or ironless brushless motors without the need for inductors. The drives can be operated in standalone mode with a speed pot or with an 0-5V analog input or a 5V pwm input from a microcontroller or microprocessor. The motor is turned off for an PW input between 0 and .5 Volts. Once power supply, motor, and speed pot (if used) are connected, the motor can be operated without the need for any adjustments, setup, or programming.
Connector termination is not needed. If reversible operation is required, a SPDT switch can be added between Dir and P-, or a 5V signal may be used. If the speed loop is to be closed in the microcontroller, a 5V or a 3.3V with 5V interface micro should be used. Input to the drive should be a 0-5V analog input (less then 1mA), or a 100-hz to 100-kHz square wave with variable- duty cycle. The brake function is accomplished by shorting the motor windings, and does not require an external braking resistor. Operating temperature range is -55 to 105 °C.