Help assembling Electromagnet Circuit

You might look up the difference between electronic schematics and a pictorial (frizzy picture). I have a large monitor and I cannot follow your picture in post #10.

Sorry, as good as I can do. :man_shrugging: No budget for an electrical engineer for a 5th grade science project :grin: I was asked earlier to draw it out by hand how it appears on the breadboard. Here is a labeled copy that is rotated.

Hi,
A simple hand drawn schematic would not be as confusing.
I have done this using a CAD, but only because my neurpathy will not let me do a decent hand drawn diag.
Why have you got all those diodes for?
Here I have drawn what you basically should need, from you post.

Tom... :grinning: :+1: :coffee: :australia:

1 Like

Thanks Tom! Not sure what you mean on the diodes. There is only one. I have no idea what it is for, I did not design it.

I think I just found what it might be. The shield design shows the switches being wired to the B terminal of the TIP120. The frtitzing shows it on the E terminal. My breadboard followed the fritz. I don't know why technically, but a lead on the wrong terminal of the transformer sure seems suspect to me. I will try it out.

Look at my schematic, the buttons go to GND, the emitter of the tip120 also goes to gnd.
You need to trace your circuits very carefully.

Tom... :grinning: :+1: :coffee: :australia:

I'm saying the original design fritz posted (which my breadboard sketch and your schematic follow for switch connection) is wrong. It contradicts the shield design showing switch connected to B terminal of TIP120. Look at the purple shield design above. It is hard to see, need to zoom in.


The only thing connected to Base terminal of the transistor is one end of the 1K resisitor in the Fritzy you posted in post#1.

Tom... :grinning: :+1: :coffee: :australia: