Info. PDF - Mindsets

Smart Motor
Speed Controller
The Mindsets Smart Motor Controller provides a simple means of controlling
standard DC motors. The output to the motor can be controlled either by a
voltage or by a potentiometer.
The circuit requires a single DC power supply between 3V and 12V. The supply
will, effectively, be connected directly to the motor when the output is at maximum, so the power supply should be chosen to match the motor (for example,
use a 6V power source with a 6V motor).
N.B. This circuit can only control brushed DC motors, not brushless or AC motors. A brushed DC motor would work when connected directly to a DC power
source like a battery.
Control with a Potentiometer
The motor speed can be manually controlled by connecting a 10k potentiometer to the input of the controller. Varying the
potentiometer simply changes the voltage on the ‘input’ pin.
Control using a Voltage
A voltage applied to the ‘input’ pin can be used to control the motor. A voltage of 0V always means no power is delivered
to the motor. The voltage required to give full power varies depending on the power supply:
• If the controller is run on 5V to 12V, then 5V on the input pin corresponds to the maximum.
• If the controller is run between 3V and 5V, then the supply voltage corresponds to the maximum.
The motor is controlled using Pulse Width Modulation (PWM). Power to the motor is pulsed about 7,000 times per second. The ratio of the length of the pulse to the gap between pulses (duty cycle) determines how much power is delivered
to the motor. It is advisable to keep wires to the motor short and twisted together to help reduce interference caused by
the PWM.
Designed and manufactured by:
Mindsets (UK) Ltd
Unit 10, The I.O. Centre
Waltham Cross, Herts
01992 716 052
© 2010 Mindsets (UK) Ltd