News Category

Electrician Knowledge

Transformer type

Constant voltage transformer
Constant voltage transformer is based on the principle of ferroresonance made of an AC voltage stabilizing transformer. Its output voltage change does not exceed ± 1%, even if the output of the constant voltage transformer output short circuit failure, it will not show any damage within 30min. Constant voltage transformer in use, as long as connected to the rectifier bridge and filter capacitor, you can form a DC power supply, eliminating the need for the remaining regulator circuit.
 
Power Transformers
Regulators and a variety of home appliances used in power transformers belong to step-down power transformer power transformer. Main applications of power transformers are boost (boost AC) or buck (lower AC). The primary (primary) winding of the step-up transformer has less efficiency (less turns) than the secondary (secondary) winding. Power transformers have E-type power transformers, C-type power transformers and toroidal power transformers.
 
E-type power transformer core is made of silicon steel overlap. The disadvantage is the larger air gap in the magnetic circuit. Electrical noise during work. Advantages of adult low.
Compared with the "E-type power transformer," C-type power transformer core is formed by two identical C-core (made of cold-rolled silicon steel) rival. The magnetic circuit in the smaller air gap, performance has improved.
Toroidal power transformer core is made of cold rolled silicon steel coil. Leakage magnetic pole is small, work less electrical noise, but also to achieve impedance matching between circuits.
 
Low-frequency transformer
Low-frequency transformers are used to weigh poundsignal voltage and signal power. Isolation of the DC. Divided into interstage coupling transformer, input transformer and output transformer, shape and power transformer similar.
 
Inter-polar coupling transformer
Interstage coupling transformer used in two audio amplifier between. The preamplifier circuit output signal sent to the latter level, and make the appropriate impedance transformation.
Enter the transformer
The input transformer is the transformer used between the audio driver stage and the power amplifier stage, which was used in early semiconductor radios. From the signal coupling, the role of transmission, it is also called to promote the transformer. Input transformers have single-ended input and push-pull input. If the push circuit is a single-ended circuit, the input transformer is also a single-ended input transformer; if the push circuit is a push-pull circuit, the input transformer is also a push-pull input transformer. Mainly from the signal transmission and impedance matching role.
 
Output transformer
The output transformer is connected between the output circuit of the power amplifier and the speaker. Is also divided into single-ended output transformer and push-pull output transformer two.
 
High-frequency transformer
Commonly used high-frequency transformers have black-and-white TV antenna impedance converters and semiconductor radios in the antenna coil. The input is two coils in series.
 
Impedance converter
Antenna impedance converter used on black-and-white TV is the same number of windings of two windings of an impedance converter formed by double-root plastic-covered insulated wire (plastic wire) and wound around a two-hole core with high permeability. Impedance doubled; the output of the two coils in parallel, the impedance is reduced by half. Therefore, the total impedance conversion ratio of 4: 1 300Ω balanced input signal is converted to 75Ω unbalanced output signal)
The magnetic bar formed by two adjacent but independent primary (secondary) secondary windings sleeved on the same magnetic bar has two shapes of a circular rectangle. Magnet in the wave of manganese zinc ferrite materials,
Antenna Coil The antenna coil of a radio is also called a magnetic antenna. The grain is black; short-wave bar magnets using nickel-zinc ferrite materials, the grains were brown. Coils generally use multi-strand or single strand wrapped in a little thicker winding rod in the insulation of the magnetic paper tube, wound around and then set in the magnetic rod.
 
Medium frequency transformer
Medium frequency transformer shape and radio oscillation coil similar, commonly known as "Middle Week", is widely used in radio or black and white TV. IF transformers belong to the adjustable core transformer. Also by the shield shell, magnetic cap (or core) nylon brackets, workers "word core, pin stand etc .. In the circuit play a role of signal coupling and frequency selection, etc .. Medium frequency transformer is the main choice of semiconductor radios and black and white TV Frequency components.Adjust its core, change the coil inductance, you can change the sensitivity of the intermediate frequency signal selectivity and passband.Motor in the radio frequency transformer is divided into FM intermediate frequency transformer and AM frequency transformer, black-and-white TV in the intermediate frequency transformer Divided into the image of the local intermediate frequency transformer and audio intermediate frequency transformer. Different specifications, different types of IF transformers can not be used directly interchangeably.
 
Pulse transformer
Pulse Transformer Pulse transformers are used in a variety of pulse circuits. Commonly used pulse transformers TV output line transformer, the line to promote transformers, switching transformers, electronic ignition pulse transformer, ozone generator pulse transformer.
 
Line output transformer
 Line output transformer referred to as FBT or line flyback transformer. The TV transformers, which belong to the step-up transformer, are used to generate various kinds of upper working voltage (such as anode high voltage, accelerating pole voltage, focusing pole voltage, etc.) required by the picture tube and also provide working voltage for other circuits of the whole machine. Black and white TV output transformer with line generally by the "U-shaped core, low voltage coil, high voltage coil, shell, high voltage rectifier silicon heap, high voltage line, high voltage cap, potting materials, pins and other components, is divided into discrete Type, high-voltage coil and high-voltage silicon reactor can be removed) and integrated (fully sealed) two kinds of structure. Black TV with line output transformer in the integrated black and white TV line output transformer based on the increase of the focus potentiometer, Accelerator voltage regulator potentiometer, focusing power lines, accelerating power supply lines and voltage divider circuit.
 
Line to promote the transformer
Line to promote the transformer is also known as the incentive transformer. Then in the line to promote the circuit and the line output circuit between the signal coupling, impedance conversion, isolation and buffering and other functions, control the work of the output line of the state. Line promotion of the transformer from the "E-core (or core) skeleton and a (primary) secondary (secondary) winding etc. belongs to the pulse circuit oscillator transformer. Its main role is to provide energy to the load circuit Circuit to provide operating voltage) to achieve isolation between input and output circuits.
 
Switching transformers
Switching transformers using "EI-type or" EE-type, EC-type high permeability core, the use of the TV switching power supply circuit. The first (primary) winding is a storage winding for powering the collector of the switch. Self-excited switching power supply switching transformer primary winding also includes a positive feedback winding or sampling winding, used to provide a positive feedback voltage or sampling voltage. Switch excitation power switch primary winding also includes self-feed winding, used to switch the oscillation integrated circuit to provide operating voltage. Switching transformer secondary (secondary) side of the multi-group power release winding, multi-pulse voltage can occur, the rectification, filtering of the TV to the relevant circuits.
 
Autotransformer
Autotransformer windings are taps of a set of coils. Can not be isolated as two separate parts. When the input terminal has both direct current and alternating current, the output terminal can not filter out the direct current component and output the alternating current alone (that is, it does not have the action of blocking DC). Once, the turns ratio of the secondary winding (ie, transformation ratio) is equal to 1 divided into power isolation transformers and interference isolation transformers. The main function is to isolate the power supply, cut off the interference source coupling path and transmission channel. Generally as a black TV repair equipment.
 
Power isolation transformer
The power isolation transformer is a 1: 1 power transformer with "safe isolation". Black TV that was "suspended" power supply status. When the human body occasionally touches either end of the secondary side of the isolation transformer (secondary), no electric shock will occur (the human body can not touch the two terminals of the secondary transformer of the isolation transformer at the same time, otherwise a closed loop will be formed and an electric shock occurs) . It can make the two linked circuits independent of each other.
 
Interference isolation transformer
Interference Isolation Transformer is a transformer with noise interference suppression. Can not form a loop, thereby effectively cutting off the interference signal path so that the interference signal can not enter from one circuit to another. Its main role is voltage transformers and impedance transformation.