Practical Electronics/Common Problems
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it used to work, but no more
[edit | edit source]If it works once, most electronic devices will continue to work almost indefinitely. There are a few exceptions:
- nearly every electronic component will be permanently damaged or destroyed, if power or other connections are connected to something with a voltage too large to handle, or unexpectedly reversed. Designers often put a "protection circuit" -- such as a crowbar circuit -- between connectors and sensitive components. But with adequate protection, most components will last indefinitely:;
- transistors
- integrated circuits
- ceramic capacitors
- printed circuit boards
- Some things, even when used normally, will eventually wear out and stop working:
- primary batteries
- secondary batteries
- incandescent bulbs
- LED degradation: every LED (including the infrared LED in each opto-isolator) gradually gets dimmer and dimmer.
- aluminum electrolytic capacitors ("wet electrolytics").
- relays
High temperature and high current usually accelerates wear-out. Sometimes a heat sink can extend the life of a component.