View Single Post
Unread 04-27-2002, 08:33 PM   #17
Brians256
Pro/Staff
 
Brians256's Avatar
 
Join Date: Oct 2001
Location: Klamath Falls, OR
Posts: 1,439
Default

Basic electronics here, but please ask more questions if it isn't clear. Hopefully, you can do basic algebra, because that's all you need for this stuff.

1) Basic equation for current, voltage and resistance.
Current = Voltage / Resistance

2) Resistors in series always add together.

-----R1------R2----
Total resistance over that portion of a circuit is R1 + R2

3) Voltage can be "divided" by using two Resistive loads (resistor or fan, or whatever).

If they are equal resistive loads, the voltage in the middle is half of the voltage sent across the divider.
+12V ----R1-----<+6V>------R2---- Ground

Basically, at the mid point, the voltage is equal to:
Voltage = (Input Voltage) * (R2 / (R1 + R2))
= +12V * (R1 / (R1 + R1)) = +12V * (1/2) = +6V

So, for fans in series, things get complicated. However, all the fans are slowers. Not just the first one.
Brians256 is offline   Reply With Quote