Hi
I have an UNO board with some simple code to use a transistor to trigger a solenoid with external 12V supply. The solenoid is permanently engaged instead of ON/OFF as per the code sending signal from pin 13.
It seems the "gate" which should connect the emitter pin just stays connected all the time. Tried several brand new transistors, all the same. Only thing I can think of is a bad batch of transistors. I'm very new to arduino/electronics, any help very much appreciated.
We don't see power to the Vcc and Gnd on the solderless breadboard (sbb) in you photo.
The first step in any trouble shooting adventure is to separate circuits.
I would:
Remove the D13 wire from the sbb.
Connect the sbb location vacated by D13 to the UNO 5V power. It it turns you solenoid on then the issue is in the UNO if not the issue is in the TIP220 circuit
I don't think pin D13 should be connected to the emitter, but to the base! Emitter to GND, collector to the solenoid.
@Erik_Baas You got me thinking, not sure I remembered the TO-220 std pinout.
What I found:
- There is no such transistor TIP-220
- If you look close at the photo the device in question is an LM317. A regulator not a transistor.
The device is in a TO220 package, and SHOULD perhaps be a TIP29.
However a TO220 power transistor will not have enough current gain to drive a solenoid from an arduino pin -
Incidentally
a solenoid
does not really tell us much.
Is it one of these - that takes 8 AMPS?
You should always give full details of any hardware you are talking about, part number at the very least,
product page or datasheet links are best...
You could have the wrong kind of device (as here), wrong actual device, wrong pin-out, wrong circuit,
wrong code - we need full details to start figuring out what's actually the problem.
johnerrington:
... and SHOULD perhaps be a TIP29...
Look closely.
It's definitely an LM317 voltage regulator.
Leo..
And if you are going to provide photos - as you most certainly should - take the thing outside into full daylight (but not full sun, and use a good camera), not in a dungeon.
Well done TomGeorge - just looked like a new zealand rugby player to me.
LM317 eh - well it IS a TO220 so why doesnt it work - its the right shape.
I think here we are chasing a dodo.
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