Toroidal Transformer Structure Performance And Appalication
The transformer has the advantages of small volume, low noise, less heat and high conversion efficiency. It has been widely used in industrial automation equipment, instrumentation, petrochemical, medical and health, agricultural production, mechanical processing, scientific research, military industry, home electrical appliances and so on. Ring transformers, especially in stepper motor power applications,show excellent performance, far beyond the U-type, E-type transformer performance.The following give a brief description of the performance and application of the toroidal transformer.
Structure and performance of toroidal transformer
It was found that the eddy current loss(iron loss) of toroidal core wound coil is the smallest,then the transformer core process to ring type.Toroidal transformer core,use the thickness under 0.35mm cold-rolled silicon steel sheet,seamless roll forming.The coil evenly wound around the core,the magnetic field generated by the coil and the core magnetic circuit almost completely coincide,to achieve the AC power through the coil produced minimum eddy current loss.It reduce 50% more than the U-type, E-type transformer,thereby improving the transformer or isolation conversion efficiency.
The core of the toroidal transformer can be machined to the extent of no air gap,the stacking factor can be as high as 95% or more,the core permeability is 1.5 ~ 1.8T (the laminated core can only take about 1.2T or less),so the ring transformer electric conversion efficiency can reach more than 95%.Ring transformer core of the non-breath structure,can make the no-load current small,long-time power supply without fever.
The shape of the ring transformer is occupied by the cylinder structure,the volume reduced by about half than the U-type E-type.
.Toroidal transformer core has no air gap,the winding evenly around the ring in the core,the magnetic cycle structure is almost in a closed space,to achieve a small magnetic leakage,electromagnetic radiation is weak,strong resistance to external magnetic interference,without shielding,installed on a variety of complex structure of the electronic equipment,will not produce any electromagnetic interference.
As the core without air gap,high permeability,there is no physical structure vibration noise.Even in high current,high load operating environment,human is unable to feel the noise.
When the toroidal transformer is loaded,its temperature is very low.Usually its iron loss can be done less than 1W / kg or so,especially for small cooling space in the instrument.
The toroidal transformer power is usually determined by its diameter and height,and the higher power,the corresponding increase in volume and weight.A variety of power specifications,a variety of input and output voltage configuration,is very flexible,processing equipment is simple and fast.
The ring transformer is running at a temperature rise of only 40 °C,allowing short-time overload operation.The primary winding use B-class (130 ℃) polyester film insulation,can withstand AC 4000V,1 minute pressure test.
Application of Ring Transformer
When select toroidal transformer,according to the load voltage,current usage to determine the power of the ring transformer.The toroidal transformer is marked out of the current,which is the full output current.Overload,the toroidal transformer can output more than about 30% of the rated current. Although the toroidal transformer overload capacity is very good, require to pay attention on the following two aspects:
1,use to overloaded start device
Some devices running current is rated,but starting current is very large,sometimes more than the rated current of 30% to 50%.For example,the AC servo motor overload capacity,usually designed 3 times than the rated operating current.The current at load start is large,and the toroidal transformer is required to run in a short time.Such a drive current overload device,configure the toroidal transformer,need to consider the amount of transformer output current more than 20% of the amount of equipment current.Because frequent start overload work,will lead to ring transformer temperature rise,long time will lead to shortened transformer life.
2,applied to equipment without overload
Many devices are designed to take into account the maximum operating current,starting current does not need to overload.
For example,the stepper motor as a device power,operating current and start-up current is the same.Select toroidal transformer,as long as the output current is equal to the maximum current of the stepper motor driver or more than 10% ,there is no need to design a great margin output current of ring transformer.The stepper motor will never have an overload current condition.Most working environment,the power of the stepper motor is variable.This requires the structure design to confirm the voltage and current parameters,man-made given a reasonable power consumption.In fact,the power consumption of stepper motors is declining as the speed increases.Stepper motor configurate ring transformer is the best choice