Slot Car Speed Controller
Traduction: [ Google | Babelfish ]
Catégories : [ Bricolage/Arduino ]
I just tested the first prototype of the speed controller for the Tyco slot
cars. Currently, the Arduino reads the potentiometer with analogRead() and
applies PWM (with analogWrite()) on the base of a BC547 transistor. The
transistor acts as a driver for a FQP70N10 MOSFET which controls the motor.
The MOSFET doesn't seem to heat at all (I selected this model for exactly that
reason) and speed control works (i.e., I can drive the car on a simple ring
circuit, down to quite low speed).
My initial idea was to drive the MOSFET directly with the Arduino, but I noticed after buying a pair of those that they it's not a logic-level MOSFET. Driving it with 5 V would theoretically work (I need about 1 A, which is well within the capabilities of the device), but the internal resistance would be much higher that the value touted on the datasheet, and thus dissipate more heat (exact figures for the resistance at 5 V are not available from the datasheet).
This was a proof of concept, and the concept is therefore proven, I can start working on measuring, with the Arduino, the current delivered to the motor.
[ Posté le 7 mai 2011 à 22:21 | pas de commentaire | lien permanent ]
