Measurement tools: the shake table, the multimeter N, thermometers, pressure regulator, a number of wiring folders and heating wire.

2 Grossly, the transformer, the Isolating Transformer of excellent quality, excellent workmanship, insulation layer, invasion of paint technology is not ambiguous, bright enameled wire, the core is compact and neat, pin-head terminal specification. If you can see the inside of enameled wire, carefully observe the color and diameter of about enameled wire, fully closed there is no way the transformer core if severe corrosion is best not to. Do not believe the transformer plate standard value, be careful to be misled! !

Multimeter to measure the transformer tap to find out each winding, the election in which resistance above 15 ohms do 220V input, the appropriate string into the other windings can reduce the voltage of the secondary winding. Do not electric shock when the pointer table measuring my own experience, though not fatal. But hard, and draw the winding diagram, measure the insulation degree of the shake table.

4 safelight bulb connected in series, through the 220V test bulb shunt pick the wrong does not matter pigging rest assured to do. Into the 220V AC cascaded bulb does not shine, I congratulate you find 220V input. Then the most high-end with a multimeter measuring each winding virtual voltage, and recorded in the winding diagram, attention must be the most high-end suffered losses. Regulator adjustment in the standard 220V clamp meter to measure the primary input-load current, transformer no-load current is the primary access rated voltage, secondary no-load primary current measured. The product of this current and the line voltage, compared with no-load loss, refers to the transformer core loss. It is the core in the AC magnetic field, eddy current loss and hysteresis loss and. Thus, the smaller the transformer no-load current, indicating that the better the quality of the core, and the ampere-turns design is very reasonable. In this case, is generally believed that the no-load current is similar to iron loss, no-load current size, it reflects the size of the iron loss. Less than a 10W transformer no-load current of about 7 to 15mA; 100W transformer no-load current of about 30 ~ 60mA between all considered normal. Iron loss of transformers, heat is inevitably large, if it is Yinan Pei turns unreasonable design, the no-load current is greatly increased, resulting in temperature rise to increase their life is not the president. The toroidal transformer no-load current should be less than the ordinary inserts transformer no-load current.

5, the most troublesome work, calibration of each of the secondary winding current, voltage regulator adjustment 220V, two of the primary access to the multimeter to check voltage and current of each winding with alligator clips to connect the heating wire (heating wire heating) each connected into two multimeters, moving in the electric wire alligator clip so that each winding voltage drop to 5% (personal view), the maximum operating current of the secondary winding, look at the parameters of each multimeter record each to draw the current and voltage parameters of the transformer primary voltage multiplied by current Power Transformer, the voltage multiplied by current of each winding is the winding of the power of this group, working continuously for a few hours to see the temperature rise of the thermometer temperature rise of about low transformer quality, the better. Ear close to the full capacity of the transformer, listen to the noise, the noise is about, the better the quality.

6, each winding of the transformer, the power generally similar can be connected in series to achieve the required voltage, and almost similar can take a balancing resistor connected in order to achieve the desired current. Windings can also reverse polarity to reduce the voltage (not advocate) I have used twice. Transformer can also be the first pick from the middle of this is I use the advanced use of power of the transformer should be placed about 60%, this low temperature effect, this is just my little experience wrong with welcome to give correction to jointly improve . I hope everyone can find their own power transformer.