Circuit Symbol

Hello all,

I am currently making a sprinkler system that waters its plants when the soil is dry enough. My teacher has drew in this diagram regarding how I should hook up my transistor. I dont really know what symbol this really is.

http://Resistor Resistor? - Album on Imgur

This is the actual arduino setup.

http://Ard

Thank you.

DucksandCo:
I am currently making a sprinkler system that waters its plants when the soil is dry enough. My teacher has drew in this diagram regarding how I should hook up my transistor. I dont really know what symbol this really is.

This is the actual arduino setup.

I've found posting pictures on this forum to be somewhat cumbersome. I see what appears to be two images, but nothing is visible.

EDIT: fiddling with images...

No clue what your teacher is referring to. We need to know the part number because there are three different pinouts for TO-92 transistors (2N, BC, and 2S). Since one pin in grounded, I'm guessing it's an NPN transistor with the emitter grounded.

DucksandCo:
My teacher has drew in this diagram regarding how I should hook up my transistor. I dont really know what symbol this really is.
Resistor? - Album on Imgur

Adequate information is required in order to make sense of a circuit diagram. In this case --- not enough information. Device details (eg. transistor model etc) is needed. Also - intended purpose --- ie. what is required for it to do --- should be understood in advance as well.

In this case, there's not enough details. More details are required.

Boy oh boy, looks like - GND to Emitter, + to maybe a solenoid then maybe the Collector, Dout from an Arduino to the Base.

After looking at your second picture, I could see that you're using a transistor in TO-220.

This is the pinout:
TO-220-NPN.jpg
Your teacher should have drawn the schematic this way:
powerNPNSwitch.jpg

TO-220-NPN.jpg

powerNPNSwitch.jpg

Could it be a logic level mosfet too?

Forgot to include a kickback diode.

:frowning:

Oh dear, pictures (clickable)!

larryd:
Forgot to include a kickback diode.

If your response was regarding my post, I redrew what the teacher drew, not what it should have been.

Southpark:
Could it be a logic level mosfet too?

The resistor on the lead marked Dout wouldn't be necessary and a resistor from gate to source would have been included so the gate wouldn't float when the GPIO port wasn't active.

dl324:
If your response was regarding my post, I redrew what the teacher drew, not what it should have been.

No, I was looking at the teachers image.

dl324:
The resistor on the lead marked Dout wouldn't be necessary and a resistor from gate to source would have been included so the gate wouldn't float when the GPIO port wasn't active.

This is all based on assumptions, which is why it can be a time-wasting exercise if there's inadequate details to begin with.

Additionally, if you assume a BJT, then the input could become floating under those conditions you mentioned too maybe, right?

Also ----- using series resistor for gates of mosfets is not uncommon.

It may well be a BJT. And all I'm saying is - if there's not enough information to start with - then it's like a goose chase.

Make sure your breadboard connections are correct too. Example..... hole j1 has an orange wire..... but the purpose of it is unclear. Same for hole c1.