Step-up transformers and step-down transformers are two common transformers, their main difference is the direction of voltage change and use. The specific differences are as follows:

1. Direction of voltage change

• Step-up Transformer: The role of the step-up transformer is to change the low voltage at the input to the high voltage at the output. In other words, it increases voltage, which is commonly used in power transmission to reduce energy loss.
  • Input voltage < output voltage.
• Step-down Transformer (step-down Transformer) : A step-down transformer reduces the high voltage at the input to a lower voltage for the end user of electricity, such as home or industrial equipment.
  • Input voltage > output voltage.

2. Winding turns ratio

• Boost transformer: In order to increase the voltage, the number of turns in the primary secondary winding (output winding) of the boost transformer is more than the number of turns in the winding (input winding). Therefore, the turn ratio of the booster transformer is greater than 1.
• Step-down transformer: In order to reduce the voltage, the number of turns in the secondary winding (output winding) of the step-down transformer is less than the number of turns in the winding (input winding). Therefore, the turn ratio of the step-down transformer is less than 1.

3. Application field

• Booster transformer:
  • It is mainly used in long-distance power transmission. Because the higher the voltage, the smaller the current at the same power, the smaller the loss of energy in the transmission process. A booster transformer typically raises the voltage from a power plant to the voltage of a high-voltage grid.
• Step-down transformer:
  • Mainly used in the user side power distribution, such as in household appliances, power equipment, etc., the voltage needs to be reduced to a safe voltage suitable for use. For example, when transmitting electricity to residential homes, high-voltage electricity is converted into low-voltage electricity for household use.

4. The relationship between voltage and current

According to the working principle of the transformer, the voltage and current of the transformer are inversely proportional, that is:

• Boost transformer: When the voltage rises, the current is correspondingly reduced to keep the power constant (ignoring loss).
• Step-down transformer: When the voltage is reduced, the current will increase accordingly.

The specific formula is:

V1×I1=V2×I2

Among them:

• V1 and V2 are the voltage of the secondary winding, respectively;
• I1 and I2 are the currents in the and secondary winding, respectively.

5. Structure and working principle

• Booster transformer: Usually has more secondary winding turns, so a larger core magnetic flux is required to transfer electrical energy.
• Step-down transformers: have fewer secondary turns, larger currents, and generally require smaller core and magnetic flux.

6. Use environment

• Booster transformer: Generally used for power transmission lines, power stations and other long-distance transmission needs.
• Step-down transformers: often used in residential areas, electrical equipment, substations and other places to send power to the user's home or industrial equipment for use.

Sum up

• Boost transformer: low voltage to high voltage, suitable for power transmission, reduce transmission losses.
• Step-down transformer: high voltage to low voltage, suitable for home or industrial equipment to ensure voltage safety.