## Circuit Design Edumacation

Can anyone direct me to free internet resources that will help me with circuit design?
I can usually figure out what type of parts are needed for a given circuit, but am often completely stymied by what specific parts to select - what resistor value, which transistor, what voltage and uF cap? What's available?
Thanks!

active| newest | oldestThe Art of Electronicsby Horowitz and Hill. Lots of detail without making you remember your advanced calculus.Take the colector current (how much current you want to go through it), and divide it by the hfe of it. Then multiply that by 1.3. then use ohms law to figure out the resistor value.

For example: I want 100mA to go through and the hfe of the transistor is 100

100/100 = 1mA

1mA x 1.3 = 1.3 mA

You need 1.3mA of base current

now caluculating the resistor, lets say we're using 5 volts:

5/0.0013= 384 ohms