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the diagram drawing is at the link below

http://img242.imageshack.us/my.php?image=save0215hu2.jpg

this took time and patience to figure out but i want to be sure if i did it right if you can't read it the tell me

2006-08-21 15:29:53 · 3 answers · asked by macgyver 1 in Science & Mathematics Engineering

3 answers

You have nothing correct.
Follow the answer above and get a book.

Check out the links below.
This one uses a light where your resistor should be.
http://www.ibiblio.org/kuphaldt/electricCircuits/Semi/SEMI_4.html

http://www.bergen.org/EST/Backup/electronic_projects/introtrans.htm

Yours: Grumpy

2006-08-21 21:28:40 · answer #1 · answered by Grumpy 6 · 0 0

You're showing a Darlington PNP, that is a combination of two transistors together to act as one.

A transistor must be biased properly to work. There are two junctions: the base-emitter and the base-collector. (The base is the middle layer in the transistor.) The base is the bar, the emitter is the arrow and the collector is the plain line.

In order to work properly, the base emitter junction must be forward biased, that is, it must have a current flowing through it. At the same time, the base collector junction must be reverse-biased; it must not have a current flowing through it.

You must generally use resistors to set up a voltage divider from your battery in order for this to work. What is the maximum current that you want the transistor to pass? (Look up the spec sheets for the part number on the transistor, so you will know what its limits are.) Use Ohm's Law to calculate the resistor value for that maximum current. Use the next higher standard value. Connect that between the collector and the power supply rail. (the battery voltage). Take another small resistor and connect it from the emitter to ground. This value can be one tenth of the resisitor that goes to the collector. Using Ohm's law, calculate the voltage across that resistor at maximum current. Add 0.7 volts to that. That is the voltage which must be maintained at the base. Figure out a ratio of resistors that can be used as a voltage divider to set that voltage at the base. Connect the voltage divider across the supply rails.

If you don't understand this, try going to Radio Shack and getting some beginner's hobby books on transistor circuits. they show you everything there, including diagrams. Good luck and have fun!

2006-08-21 23:05:16 · answer #2 · answered by cdf-rom 7 · 0 0

It looks totaly wrong. Where are your resistors?

2006-08-21 22:43:34 · answer #3 · answered by mrlong78 2 · 1 0

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