Electronics notes/Inductors and transformers: Difference between revisions
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* isolation transformer | * '''isolation transformer''' | ||
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: purpose being galvanic isolation and/or floating | : purpose being galvanic isolation and/or floating | ||
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* '''modulation transformer''' | * '''modulation transformer''' | ||
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Other design properties | '''Other design properties''' | ||
* potted transformers, print transformers | * potted transformers, print transformers | ||
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: potted transformers do not expose their coils, just the connections. (why?) | : potted transformers do not expose their coils, just the connections. (why?) | ||
: print transformers are basically through-hole components, often fairly small | : print transformers are basically through-hole components, often fairly small | ||
: this makes them a little easier to mount them in a less-touchable so safer way | : this makes them a little easier to mount them in a less-touchable so safer way | ||
: yet most of these do not have high VA ratings (mostly because of heat details{{verify}}) | : yet most of these do not have high VA ratings (mostly because of heat details{{verify}}) | ||
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* '''audio-frequency transformers''' | |||
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: should carry at least 50~15kHz (preferably 20..20kHz) fairly transparently | |||
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* '''power-frequency transformers''' - are designed for power transfer, at 50Hz | |||
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* '''multi-phase transformers''' | |||
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: are usually only used in power transmission | |||
: so may be higher-frequency designs | |||
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* '''grounding transformer''' | |||
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: https://en.wikipedia.org/wiki/Grounding_transformer | |||
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* '''distribution transformer''' | |||
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: often the last step in longer-distrance transmission, namely going from local-grid voltages to consumer levels | |||
: https://en.wikipedia.org/wiki/Distribution_transformer | |||
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Latest revision as of 21:12, 28 June 2024
Inductors
Inductor intro
Core inductor (design)
Stick inductor (design)
Toroidal inductor (design)
On magnets
See also
http://electronics.stackexchange.com/questions/12930/capacitors-or-inductors
http://www.avrfreaks.net/forum/inductor-current-smoothing
Filters (application)
(compared to RC filters)
(Note: The L seems to refer to Lenz)
RL filter (application)
LC filter (application)
Choke (application)
Ferrite beads
Ferrite beads, also known as ferrite chokers, are designed to eat a certain range of frequencies, and turn it into (a negligible amount of) heat.
They work as inductors, and act as a passive low-pass filter.
One thing they address are that oscillators such as clock generators (and modern power supplies, since they're typically switch-mode) act as little radio-frequency transmitters, particularly when there is something around to act like an antenna, such as wires.
So high frequencies easily get around. While most things are fine with a little high frequency EM around, not always. So there's regulations about this.
You pass these tests by suppressing things. Ferrite beads can do this.
Note that often it's easier to suppress earlier (near the source) rather than later (on an external wire), meaning that ferrite beads are sometimes a sign of laziness.
And in some cases they're not particularly necessary for your case, but e.g. qualifying for worldwide RF emission tests made it easier to slap one onto the cable and be done with a single variant that passes worldwide.
Note that since they're inductors, mis-applied ferrite beads could cause resonance. So don't just slap on one you found somewhere because you think it will Magically Make Things Better.
See also:
- http://computer.howstuffworks.com/question352.htm
- http://images.google.com/images?q=ferrite+beads
- http://www.analog.com/en/analog-dialogue/articles/ferrite-beads-demystified.html
Transformers
Named purposes / designs
- isolation transformer
- control transformer
- instrument transformer
- modulation transformer
- Autotransformer
- Variable Autotransformer
- neon-sign transformer
- trigger transformer
Other design properties
- potted transformers, print transformers
- audio-frequency transformers
- power-frequency transformers - are designed for power transfer, at 50Hz
- multi-phase transformers
- grounding transformer
- distribution transformer