How Do Resistors, Diodes and Capacitors Work In Relation To Electronic Fuel Injection
Written by wolfems on September 10, 2009 – 2:42 pm
Hi Everyone.
This is not going to be a big lesson on electronic theory, but I thought a lot of you have been asking about some basic info on resistors, caps and diodes, like “what does a diode do?”
So I thought a quick look at these might help you feel a little more comfortable when dealing with them. So here we go……….
Resistors:
Imagine a bar of copper. It has an extremely low resistance. If you put it across a car battery, there will be sparks, and you may even destroy the battery. It allows a massive amount of current to flow through itself.
Resistors can be used to limit the amount of current flowing through a wire. OR they can be used to reduce the voltage on a wire or from a sensor. Imagine the current flow like it is water and it is running through a tap. As the resistance increases (like turning off the tap), less water (current) is able to flow through the wire.
Like a tap, it doesn’t matter which way around the resistor goes, the water can flow either way.
Capacitors:
Capacitors are sort of like shock absorbers. Imagine all of the bumps in the road is like a noisy waveform on a wire. Without any shock absorbers, your car would be bouncing up and down and rattling all over the place. You can put a little shock absorber on each wheel and the shaking and bouncing reduces a little. Put bigger shock absorbers on each wheel and the ride becomes more smooth.
The same thing happens with adding more capacitance to the signal on the wire. A little capacitor will reduce the voltage bumps a little, and the bigger you go, the more the larger bumps will be dampened.
Some capacitors can be wired either way around, but ones with either a – or a + must be wired a specific way.
Diodes:
You go to the supermarket and you walk through the turnstyle. No problem. But then you realize you forgot your money, and you try to go back. You can’t. The turnstyle only lets you travel one way.
Diodes are the same. They allow current to flow quite freely in one direction, but they stop the current from flowing in the opposite direction.
Diodes have a band at one end. Current flows from the end with no band, to the end with the band.
As I said at the beginning of this post, it is a basic overview, so anyone with more intimate knowledge of electronics, please give me a break on some of the descriptions above. They are only basic descriptions to give anyone with no knowledge on these items a way to understand some of the concepts.
