Hi, i am fairly new electronics and am working on driving a DC motor with an H-Bridge. I planned on taking a 5V digital output from my arduino UNO and using it to switch a NPN transistor that would then allow 9V to flow through and go to the H-Bridge. The H-Bridge works great, however, it is only receiving the 5V from the arduino, despite that pin being connected to the base pin of the transistor. I don’t really understand how to set this resistor up. I though i had a good understanding of how to use resistors until this trumped me. Here’s a couple pictures.
The white wire is the 5V arduino signal. I have a simple test LED set up that needs to be powered and is already grounded. With only the 5V signal being activated on the base pin, the LED is on. The 9V power line (which is the red one) is not even plugged in. I didnt know that a transistor could work with something only on 2 of the 3 pins. In the other picture you can see that i plug in the 9V (red) to the other pin of the transistor and the LED brightness did not change. I tested with a voltmeter and the voltage did not change either.
So, my question is: what am i doing wrong? What do i need to do in order to turn this 5V signal into 9V power with a transistor. I would hate to have to order opto-isolators, as that would prevent me from learning whatever it is i am doing wrong.
Thanks in advance,