Product Features

1. The SBF triple frequency transformer is simple to operate and reliable in performance



2. It can well meet the needs of induced voltage withstand tests for transformers and instrument transformers



Transformers are used in almost all electronic products. Their principle is simple, but the winding process may have different requirements depending on the application (different uses). The main functions of transformers include: voltage transformation; impedance transformation; isolation; voltage stabilization (magnetic saturation transformer), etc. The commonly used core shapes for transformers are generally E-type and C-type cores.

I. Basic Principle of Transformers



When a sinusoidal AC voltage U1 is applied to the two ends of the primary coil, an alternating current I1 flows in the wire and generates an alternating magnetic flux ф1, which passes through the primary coil and the secondary coil along the core, forming a closed magnetic circuit. A mutual induction potential U2 is induced in the secondary coil. At the same time, ф1 also induces a self-induction potential E1 in the primary coil. The direction of E1 is opposite to that of the applied voltage U1, and its magnitude is similar, thereby limiting the magnitude of I1. To maintain the existence of the magnetic flux ф1, a certain amount of electrical energy consumption is required, and the transformer itself also has certain losses. Even when the secondary side is not connected to a load, there is still a certain current in the primary coil. This current is called the "no-load current".



If a load is connected to the secondary side, the secondary coil generates a current I2, which in turn produces a magnetic flux ф2. The direction of ф2 is opposite to that of ф1, canceling each other out, reducing the total magnetic flux in the core, and thus reducing the primary self-induction voltage E1. As a result, I1 increases. It can be seen that the primary current is closely related to the secondary load. When the secondary load current increases, I1 increases, and ф1 also increases. The increase in ф1 exactly compensates for the part of the magnetic flux canceled by ф2, maintaining the total magnetic flux in the core unchanged. If the losses of the transformer are not considered, it can be assumed that the power consumed by the secondary load of an ideal transformer is exactly the electrical power that the primary side draws from the power source. A transformer can change the secondary voltage by changing the number of turns of the secondary coil as needed, but it cannot change the power that the load is allowed to consume.



II. Transformer Losses



When the primary winding of a transformer is energized, the magnetic flux generated by the coil flows in the core. Since the core itself is also a conductor, an electromotive force is induced on the plane perpendicular to the magnetic field lines. This electromotive force forms a closed circuit on the cross-section of the core and generates a current, which is like a vortex, so it is called "eddy current". This "eddy current" increases the losses of the transformer, heats up the core, and increases the temperature rise of the transformer. The loss caused by "eddy current" is called "iron loss". In addition, a large amount of copper wire is needed to wind the transformer. These copper conductors have resistance, and when current flows through them, this resistance consumes a certain amount of power. This part of the loss is often converted into heat and dissipated. We call this loss "copper loss". Therefore, the temperature rise of a transformer is mainly caused by iron loss and copper loss.



Since transformers have iron loss and copper loss, their output power is always less than the input power. For this reason, we introduce an efficiency parameter to describe this: η = output power / input power.