Welcome to the third part. This will cover resistance. For us armature electronic engineers the component that we will use the most are resistors. Every circuit uses resistors. Actually, every circuit uses capacitors too, but not as frequently as resistors.
Resistors, as the name implies, cause resistance in the circuit. Using our hydraulic analogy, think of a resistor as a crimp in the pipe that restricts the flow of water. This is measured in ohms.
So V is the pressure, I is the rate of flow, and R is the resistance of the flow.
Let's set up a simple circuit consisting of a power source (V) and one resistor, and an ammeter.
Lets say we are using a 10 volt battery and we have a 100 ohm resistor.
Using simple algebra we can rearrange V=IR to solve for I. I=V/R.
I = 10/100
I = 0.1 amperes (amps), or 100 mA. This is the reading we would see on the ammeter.
If we increase the resistance and keep V the same, the current will decrease. If we decrease the resistance, the current will increase.
It is actually much harder to under stand the "why" than it is to do the math with this equation.
The next installment will be an introduction to the various electronic components that you will frequently see in a circuit.
No comments:
Post a Comment