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What is a transformer choke?
A “choke” is the common name given to an inductor that is used as a power supply filter element. They are typically gapped iron core units, similar in appearance to a small transformer, but with only two leads exiting the housing.
How does choke transformer work?
In electronics, a choke is an inductor used to block higher-frequency alternating currents while passing direct current (DC) and lower-frequencies alternating current (AC) in an electrical circuit. The name comes from blocking—”choking”—high frequencies while passing low frequencies.
What does a transformer power choke do?
In electronics, a choke is an inductor used to block higher-frequency alternating currents while passing direct current (DC) and lower-frequencies alternating current (AC) in an electrical circuit.
What does a choke do on a DC motor?
Do you need two windings for a choke transformer?
A transformer does not need two windings to be a transformer, it needs to do a conversion using a magnetic field. I (personally) have used a transformer as a choke by ignoring one of the windings. It still looks like a transformer, but it isn’t acting like a transformer.
What makes a choke a special case of a transformer?
You may think of a choke as a special case of a transformer, where a transformer is defined as 1 or more windings on a common core such that they share their magnetic field. To make a transformer you start out by first making a choke when you add the first winding.
How big of a wire do I need for a choke?
The general rule of thumb for a modest-sized transformer or choke is to size the wire to 0.3 to 0.4 mm 2 per amp (from references 1 and 2, above) which would imply that for 200mA the minimum wire would need a cross-sectional area of around 0.06mm 2 which corresponds to #29 AWG.
Why do you use ferrite cores in a choke?
This is why a ferrite cores is used. In a choke or inductor design, the application is for energy storage, and there is always a DC current flowing through, so you want to use a iron powder, MPP, sendust or high flux cores. Also, the saturation flux is a lot higher, so a higher DC current can flow through.