Dongguan 2016 Chashan Electrician Certificate Agency Review

Voltage and current that change regularly in magnitude and direction with time are called alternating current. Sinusoidal alternating current is a voltage and current that changes over time according to a sinusoidal function. The magnitude and direction of alternating current change with time, that is to say, the values of voltage (electromotive force) and current are different at every instant. The analytical diagram of a sine wave is shown in Figure <>-. If a point on the circle starts to rotate at a constant angular speed, at any time, such as,, &;&; The coordinates on the axis (or components on the axis) can be expressed by the formula &; of the sine function. Assume that the circle The radius is r, the phase angle is &;, when rotating around the center of the circle, the value of and the rotation angle
Contact person: Teacher Li
Consultation phone number:
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School name
: Dongguan Guangyou Vocational Training School
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Address: Third floor of Dongguan Bus Terminal East Station (Guangyou Education)
Guangyou Vocational School opens classes all year round
,
Learn electrician and send electrician exam practice software
Guangyou Education
Training objectives
: Starting from zero basics, we will guide students in all aspects, how to connect indoor and outdoor wires, emergency first aid and treatment of electric shock, practical electrician operation and theoretical use, safe operation, on-the-job operation and employment experience practice
Specific electrician training course introduction:< br/> Introduction to the junior electrician training course:
Safe operation of electricians
.
Basic knowledge of electrical circuits
.
Calculation of circuits
.
Series, parallel connection and application of resistors
.
Alternating current, direct current
.
Single-phase alternating current, three-phase alternating current
.
Transformers, mutual inductors< br/> .
Single-phase electricity meter, three-phase electricity meter
.
Motor
.
Use of electrical instruments
.
Multimeter
/> .
Megohmmeter
.
Current clamp meter
.
Ammeter
.
Voltmeter
.< br/>Applications of low-voltage electrical appliances
.
Fuses
.
Knife switches
.
Circuit breakers
.
Contactor
.
Thermal relay
.
Intermediate relay
.
Time relay
.
Button
.
Lighting circuit practical operation
.
Industrial power circuit practical operation
.
Motor forward rotation control
.
Motor interlocking forward and reverse rotation Control circuit
.
Double interlocked forward and reverse control circuit
.
Workbench automatic reciprocating control circuit
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Motor sequential start control circuit< br/> .
Motor voltage reduction starting control circuit
Intermediate electrician training course training content: electrical control technology, electrician and electronic basics, maintenance electrician technology, internal and external line electrician
Technology,< br/> Electrical equipment operation,
Transformer and motor operation and maintenance, programmable controller principles and applications,
Electrical
Electrical measurement knowledge, practical operations, etc. Advanced training content: digital circuit technology, factory Power transformation and distribution technology,
Factory electrical control technology,
Principle and application of programmable controller,
Principle and practical technology of single chip microcomputer,
Rectifier and
inverter technology , Inverter principle and application technology, practical operation, etc.
In modern industrial and agricultural production and daily life, the electric energy sent from power stations is alternating current, while the energy provided by various batteries is direct current. Alternating current has obvious advantages and great economic significance in production and use. For example, when transmitting over long distances, increasing the voltage of alternating current and using high-voltage transmission lines can reduce power loss on the line; when the power is delivered to users, the voltage can be reduced for safe use. This step-up and step-down can be easily realized by transformers in AC power supply systems. Many electrical devices, such as AC asynchronous motors and lighting equipment, are driven directly from AC power. Alternating current can also be converted into direct power with the help of transformers and rectifiers