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 | ||
: may carry a reasonable amount of power | : may carry a reasonable amount of power | ||
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:: This one is a specific design that does nothing else, so is often 1:1 ratio, unless you want to do something else at the same time | :: This one is a specific design that does nothing else, so is often 1:1 ratio, unless you want to do something else at the same time | ||
: https://en.wikipedia.org/wiki/Isolation_transformer | : https://en.wikipedia.org/wiki/Isolation_transformer | ||
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* '''control transformer''' | |||
* '''control transformer''' (a.k.a. Industrial Control Transformers, Machine Tool Transformers, Control Power Transformers) | <!-- | ||
: (a.k.a. Industrial Control Transformers, Machine Tool Transformers, Control Power Transformers) | |||
: isolation transformer to avoid floating/common mode issues{{verify}} | : isolation transformer to avoid floating/common mode issues{{verify}} | ||
: also designed to give more stable output during inrush | : also designed to give more stable output during inrush | ||
: seen in industrial panels and such{{verify}}, | : seen in industrial panels and such{{verify}}, | ||
: often single phase, grounded{{verify}}. | : often single phase, grounded{{verify}}. | ||
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* '''instrument transformer''' | * '''instrument transformer''' | ||
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: a.k.a. accurate-ratio transformer, because accuracy of the measurement/indication depends on that | : a.k.a. accurate-ratio transformer, because accuracy of the measurement/indication depends on that | ||
: intended for instruments that wish to ''measure'' highish voltages or currents, by transforming it to more usual levels | : intended for instruments that wish to ''measure'' highish voltages or currents, by transforming it to more usual levels | ||
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: Potential Transformer - instrument transformer to measure voltage | : Potential Transformer - instrument transformer to measure voltage | ||
: https://en.wikipedia.org/wiki/Instrument_transformer | : https://en.wikipedia.org/wiki/Instrument_transformer | ||
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* '''modulation transformer''' | * '''modulation transformer''' | ||
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* '''audio-frequency transformers''' | |||
* '''audio-frequency transformers''' - should carry at least 50~15kHz (preferably 20..20kHz) fairly | <!-- | ||
: 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 | * '''power-frequency transformers''' - are designed for power transfer, at 50Hz | ||
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* '''multi-phase transformers''' | |||
* '''multi-phase transformers''' - are usually only used in power transmission | <!-- | ||
: are usually only used in power transmission | |||
: so may be higher-frequency designs | : so may be higher-frequency designs | ||
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* '''grounding transformer''' | * '''grounding transformer''' | ||
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: https://en.wikipedia.org/wiki/Grounding_transformer | : https://en.wikipedia.org/wiki/Grounding_transformer | ||
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* '''distribution transformer''' | |||
* '''distribution transformer''' - often the last step in longer-distrance transmission, namely going from local-grid voltages to consumer levels | <!-- | ||
: often the last step in longer-distrance transmission, namely going from local-grid voltages to consumer levels | |||
: https://en.wikipedia.org/wiki/Distribution_transformer | : https://en.wikipedia.org/wiki/Distribution_transformer | ||
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* '''Autotransformer''' | * '''Autotransformer''' | ||
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: autotransformers are a single coil, tapped, making the them both electrically and magnetically connected {{comment|(rather than two coils that are coupled only magnetically, and electrically isolated)}} | : autotransformers are a single coil, tapped, making the them both electrically and magnetically connected {{comment|(rather than two coils that are coupled only magnetically, and electrically isolated)}} | ||
: has lower voltage drops / higher efficiency | : has lower voltage drops / higher efficiency | ||
: considered unsafe for larger-scale power distribution because high and low voltage are directly connected | : considered unsafe for larger-scale power distribution because high and low voltage are directly connected | ||
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* '''Variable Autotransformer''' | |||
* '''Variable Autotransformer''' | <!-- | ||
: once [[trademark]]ed Variac, now [[genericised trademark|genericised]] and effectively a synonym) | |||
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* '''neon-sign transformer''' | * '''neon-sign transformer''' | ||
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: high voltage (~10kV), low current capacity (~30mA) | : high voltage (~10kV), low current capacity (~30mA) | ||
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* '''trigger transformer''' | * '''trigger transformer''' | ||
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: meant to create a high voltage pulse, often for gas ionization, e.g. for strobe lights | : meant to create a high voltage pulse, often for gas ionization, e.g. for strobe lights | ||
: https://en.wikipedia.org/wiki/Trigger_transformer | : https://en.wikipedia.org/wiki/Trigger_transformer | ||
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Other design properties | Other design properties | ||
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====Bootstrap, feedback, and other windings==== | ====Bootstrap, feedback, and other windings==== | ||
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Revision as of 21:11, 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)
✎ This article/section is a stub — some half-sorted notes, not necessarily checked, not necessarily correct. Feel free to ignore, or tell me about it.
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
✎ This article/section is a stub — some half-sorted notes, not necessarily checked, not necessarily correct. Feel free to ignore, or tell me about it.
- isolation transformer
- control transformer
- instrument transformer
- modulation transformer
- audio-frequency transformers
- power-frequency transformers - are designed for power transfer, at 50Hz
- multi-phase transformers
- grounding transformer
- distribution transformer
- Autotransformer
- Variable Autotransformer
- neon-sign transformer
- trigger transformer