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Topic: PNP transistors... how to use them? (Read 4 times) previous topic - next topic

mmcp42

another thing to try
disconnect the resistor from the arduino and connect it to +volts
that should stop the motor
there are only 10 types of people
them that understands binary
and them that doesn't

eddiea6987

okay ill try that in a sec, while i do that this is my connections, however i did not draw the resistor or diode so simplicity sake and i wanted to draw it fast before you logged out heheh
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

eddiea6987

this connection shown above makes the motor run just all out , no pwm.
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

eddiea6987

#13
Jul 06, 2011, 11:27 am Last Edit: Jul 06, 2011, 11:29 am by eddiea6987 Reason: 1
as a matter of fact with that connection right there the arduino doesnt even have to have power for the motor to run so i am basically making a complete circuit.
swtich the C and E connections makes absolutely nothing happen . so i dont know
I could print the Arduino logo on a box of cereal and sell it as "Arduin-O's"

mmcp42

you can't just swap pins around and hope
(well you can but the magic smoke will soon leak out if you do)

a) you MUST have a resistor between base and arduino - to keep the magic smoke in the arduino
b) you have emiiter and collector the wrong way round - transistor will work backwards, but very badly and the smoke will soon leak out
c) you MUST put a reverse diode across the motor, the back emf will kill the transistor - and you know what happens to the magic smoke!
d) did you try connecting the resistor to +12? - it will turn the transistor off - and the motor should stop

I can't tell which transistor you are using so can't tell if E B and C are correct
also what size motor is it? (no not inches - current rating!)
there are only 10 types of people
them that understands binary
and them that doesn't

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