Hy
I got an old cordless drill with PWM control of speed.
The right image is my circuit right now. The motor starts to turn if i only tuch the blue dot pin, and slowly stops. If conect to +5V nothing happens. Any suggestion on how to get this thing going?
It should supposed to be a 25A @ 15Vmax.
Is it possible to control this from Arduino with PWM?
If I am correct, the pins are:
G = Base
D = Collector
S = Emiter
Wright?
GDS is Gate Drain Source, indicating a MOSFET.
Many MOSFETs that are not specifically for use with microcontrollers will need 10V on the Gate to turn on fully.
Is it possible to control this from Arduino with PWM?
Yes possible, but not directly from an arduino output pin. The device is a mosfet that requires normally a +10vdc or higher to insure full on for the mosfet. So you would need a switching transistor to interface from the arduino 0 to +5vdc PWM switching to a 0 to +10 or higher voltage (but stay under the mosfets maximum allowable gate voltage) PWM signal it should work OK. What is the battery voltage run at?
Lefty
Thank you both for explanation!
Battery voltage is 14.4V.
How do i switch positive (+) current to mosfet? This cant be done with TIP120 wright?
You use a pull-up resistor to connect the Gate to +14.4V and use an NPN transistor to connect the Gate to Ground. When the transistor is OFF the pull-up resistor makes sure the MOSFET is fully ON. Use a 200+Ohm resistor between the Arduino pin and transistor Base to limit Base current.
You will find that the sense of PWM is inverted: 255 is OFF and 0 is FULL ON.
Can you show the full markings on that MOSFET - it may be logic-level in which its simple to interface. If not just replace it with a logic-level MOSFET.
Logic level mosfets have the words "Logic Level" at the start of the datasheet, or have a rating that looks like "Rds(on) = xxx ohms at Vgs=4.5V" (sometimes Vgs=5.0V). If there is only a specification with Vgs=10V then its unlikely to be logic level.