Electrical – Help understanding current direction with transistor

transistors

I'm an electronics hobbyist struggling with the concept of transistors. I made a simple circuit with a PNP transistor based off of a diagram, but don't understand how it works.

From the book containing the diagram:

Look carefully at schematic I. You see there are two paths for the current: one from base to emitter and another from the collector to emitter. The transistor is a PNP type. Notice the base to emitter path is open until you press the key.

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What I dont get is the direction of current flow. I read that current has to flow against the direction of the arrow, but looking at the circuit, how could the LED light up if electrons can only pass the other direction? (opposite the blue arrow?)

Also I would really appreciate an explanation of the values for power sources (3V and 6V); On the board, V6 is 9 Volts while v4 is 6 volts so I'm unclear how they arrived at those values. Really appreciate your help; I've spent hours researching this and still am baffled.

Here's a picture of my circuit board:

enter image description here

Best Answer

What I dont get is the direction of current flow. I read that current has to flow against the direction of the arrow, but looking at the circuit, how could the LED light up if electrons can only pass the other direction? (opposite the blue arrow?)

You are confusing conventional current flow and electron flow. In this circuit, when the switch is closed, electrons flow will be in the direction of your blue arrow, meaning that conventional current will be flowing opposite the direction of the arrow, exactly as required to light the LED.

Probably your book is trying to teach things in terms of electron flow rather than conventional current flow. In any case, they have drawn their schematic with entirely different conventions than the rest of the world uses. Throw that book away and get one that will teach electronics in a way that will allow you to communicate with other electronics hobbyists and electrical engineers.