American 3 pin plug

Type B Electrical Outlet (American 3 pin Plug)

Type B Electrical Receptacle

Countries Using Type B Electric Plug

Information on the Type B American 3-pin Electrical Adapter Plug and Electrical Outlet

The Type B electrical plug has two flat parallel blades like the Type A, but also has a round grounding or earth pin that grounds the device before the power is connected. The neutral blade is wider than the live blade to ensure proper insertion.

Type C
All of the noted for Type A except Bangladesh, Bolivia, Cambodia, China, Dominican Republic, Korea, Liberia, Maldives, Peru, St. Vincent, Tahiti, Thailand, Vietnam, Yemen. Also found in Azores, Belize, Trinidad and Tobago.

Information on The Type B Electrical Outlet

The technical name for the Type B is NEMA 5-15 (North American 15 A/125 V ground ed). It is also called the North American 3-pin. The ground pin is longer than the live and neutral blades, so the device is grounded before the power is connected. The Type B outlet has a ground at the bottom, the neutral slot to the left, and the live slot to the right. This outlet can also be installed with the ground at the top or to either side. Japan also uses a Type B similar to the North American, but it is less common than the Type A equivalent.

Type C Electrical Outlet

North American Plug

Type A Electrical Outlet (North American Plug)

Type A Electrical Receptacle

Countries Using Type A Electric Plug

The Type A electrical plug, or flat blade attachment plug, uses two flat parallel pins or blades. It is found in most of North America and on the east coast of South America on smaller devices that do not require a ground connection.

Type C
American Samoa, Anguilla, Antigua, Aruba, Bahamas, Bangladesh, Barbados, Bermuda, Bolivia, Brazil, Cambodia, Canada, Cayman Islands, China (without holes in blades and slightly shorter blades), Colombia, Costa Rica, Cuba, Ecuador, El Salvador, Guam, Guatemala, Guyana, Haiti, Honduras, Jamaica, Japan, Laos, Lebanon, Liberia, Maldives, Mexico, Micronesia, Montserrat, Netherlands Antilles, Nicaragua, Niger, Okinawa, Panama, Peru, Philippines, Puerto Rico, St. Vincent, Saudi Arabia, Tahiti, Taiwan, Thailand, United States, Venezuela, Vietnam, Virgin Islands (U.S.& British), Yemen.

Information on The Type A Electrical Outlet

Technically known as the NEMA 1-15 (North American 15 A/125 V ungrounded), this simple plug has two flat parallel pins, or blades.Early designs allowed the blades to be inserted either way, but more modern plugs make the neutral blade wider than the live blade so that a polarized plug can only be inserted one way. New polarized Type A plugs will not fit in old Type A sockets, but both old and new Type A plugs will fit into new Type A and Type B sockets. A similar plug and socket are commonly found in Japan, the JIS C 8303, Class II (Japanese 15 A /100 V ungrounded). It is basically identical to the North American, but incorporates stricter dimensional requirements for the plug housing, marking, and mandatory testing and approval. Japanese plugs
should be able to fit North American outlets, but North American polarized plugs may require adapters or replacement non-polarized plugs in order to connect to older Japanese outlets.

Type B Electrical Outlet

Output Plugs and Connectors

When purchasing AC-DC linear and switching power supplies, you must specify the output plug and connectors specification. This article will for help determining the units that you need.


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Item Code Item
Type
Description Image
.725 Output Plug 0.7 X 2.5 X 10MM (EIAJ-1)
.725-HP Output Plug O.7 X 2.5 X 10MM (HARD PLASTIC EIAJ-1)
.932 Output Plug 0.9 X 3.2 X 9.0MM

AC Input

Larger power supplies may use three phase power. These can be more economical and a bit more efficient than single phase supplies, although the ripple frequencies will be higher.

Isolation: specified as the DC or AC voltage that can be applied between input and output without the supply failing. Typical numbers are 500 to 1500 V. The power supply’s isolation between input and output or chassis comes from the isolation provided by the supply’s transformer.

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Ripple and Noise

There’s no universally-accepted method of measuring ripple and noise. Some sellers include external circuitry in making the measurements, so to duplicate their results, you will need to contact them how they make their measurements. The easiest measurement is to connect an AC-coupled oscilloscope to the output of the power supply. The measurement can be made of common-mode noise (noise on both + and – outputs of the power supply with regard to the AC power ground) or normal-mode (also called differential-mode) noise, which is the noise seen between the + and – terminals of the power supply. Note: since the outside of the BNC connector on many scopes is connected to the power ground, you’ll have to use an isolation transformer to power the scope or use a differential amplifier to measure the normal-mode noise.

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Conditions for design high frequency transformer

It is greatly appreciated customer give us those conditions before you need High frequency transformers samples:

(1)Circuit topology
Flyback type, forward type, push-pull, half-bridge, etc

(2)Input voltage range
The lower limit of rectified voltage is important, in particular.

(3) Operating frequency
It is especially necessary to determine the lower limit frequency for the maximum load condition in Flyback converter.

(4) Maximum duty ratio
It is necessary to specify maximum ON time when input voltage is lower limit, approximately 45% should be the maximum for external excitation system.

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Switching Mode Power Supplies

A problem of linear power supply is the size and weight of the transformer. The size is required because of the low frequency (50 to 60 Hz). For the same power output, the transformer size goes down as the frequency goes up (up to a point). The SMPS takes advantage of this by chopping the AC line’s waveform into lots of little pieces and changing them to a desired voltage level with a much smaller transformer. A key fact is that the switching element is either off or fully on (saturated). The voltage drop across the transistor is small (for either a bipolar transistor or a MOSFET), meaning little power is being wasted in it. When it’s off, no power is being dissipated. This is one of the efficiency wins of a SMPS.

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Linear Regulation

The principle of operation of a linear regulation power supply is shown in the following diagram:
Linear Regulation


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Glossary of power supplies (3)

Minimum load: If specified for a power supply, it is the minimum load current that must be drawn from the power supply so that it meets its performance specifications.

Surge: A momentary increase in the AC power line voltage.

Output impedance: The ratio of a change in output voltage to a change in load current.

Power factor: The ratio between real and apparent power. This determines how much
current is required to produce a certain amount of power. It is always desirable to have the ratio be as close as 1. A lower power factor system would mean greater loss in power to produce the same amount of work as compared to with a higher power factor system.

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Glossary of power supplies (2)

AC: Alternating current. Describes voltage and current that varies in amplitude, usually in a sinusoidal waveform with respect to time. AC power is almost universally used for distributing electrical power.

Blackout: Loss of AC electrical power.

Brownout: A planned AC voltage reduction by the power company to counter excessive demand.

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