Components Revision

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Selecting the correct components can be tricky. There is a big choice so some technical understanding is useful.

Here are some questions and a check list of things to consider ...

Current: What is the maximum safe current?
Check the component data sheet.
Learn how to measure current.
Resistance: Will you need a current limiting resistor?
Check the component data sheet.
Learn how to calculate resistor values.
Power: How hot will it get?
Learn how to calculate power.
Polarity: Does is matter which way round the component is connected.
Check the component data sheet.
Learn how to read the labelling on components.
Voltage: What is the maximum safe voltage?
Check the component data sheet.
Learn how to measure voltage.
Tolerance: How accurate do the component values need to be?
Electrolytic Capacitors +/- 20%
Normal Capacitors +/- 5%
Resistors +/- 5% or 2% or often 1%

If you need to flash a light, the flashing speed is not too important. If you want to generate music that sounds in-tune, better accuracy is critical.