Circuit diagrams show how electronic components are connected together. Each component is represented by a symbol and a few are shown here:

Circuit diagrams and component layouts
Circuit diagrams show the connections as clearly as possible with all wires drawn neatly as straight lines. The actual layout of the components is usually quite different from the circuit diagram and this can be confusing for the beginner. The secret is to concentrate on the connections, not the actual positions of components.

This is an important action when checking the circuit performance for analysis or when you repair a circuit/electronic device.

When testing circuits you often need to find the voltages at various points, for example the voltage at pin 2 of a 555 timer chip. This can seem confusing – where should you connect the second multimeter lead?

Measuring voltage at a point

• Connect the black (negative -) lead to 0V, normally the negative terminal of the battery or power supply.
• Connect the red (positive +) lead to the point you where you need to measure the voltage.
• The black lead can be left permanently connected to 0V while you use the red lead as a probe to measure voltages at various points.
• You may wish to fit a crocodile clip to the black lead of your multimeter to hold it in place while doing testing like this.

I am installing a backup camera into my car the license plate light is blinding the camera at night time making it useless. I can’t figure out the name of the electronic component i need. There are two inputs and one output. A is the reverse light volt. (just used for signal). B is the license plate light. C is the output of the circuit.Normally A is off (when moving forward) so only B is detected and there is an output from C. When voltage is detected on input A, the circuit should cut power to output C.

-Thanks

I got a scanner, i know it got a very simple circuit board because i open it once, but it need warm up if i didn’t use it for a month, if i use it yesterday, it won’t require warm up to function as normal. So what is the component that need to replace, i suspect it would be the capacitor, if it is the case, would the big capacitor fail 1st or the small one. Any electronic repair expert kindly give me some ideas, thanks.

I’m looking for some sort of reference that illustrates and dimensions electronic component standards. Like SOIC, DIP, PLCC. I need to create CAD models of various components so I would like to find drawings of all of the most common EE packages. Does anyone know where to look? Thanks.