Membrane switch this little device contains a university asked, which it adopted the harmonic current suppression technology.This technique has a total of four ways, choke input mode, partial smoothing mode, single conversion mode and double transformation method, then, to the west with us to get to know the content of these technologies is how to:
1. The choke input mode
This way is in the power input level such as choke, noise filter or reactor, at present, is used to suppress the harmonic current and electromagnetic interference a mixture of both small choke coil and small reactor and small special harmonic current suppression noise filter are under development.
2. Single transformation way
Simple circuit design, the way to lose one level without having to meet people reactor, ac input can be directly connected to the load, the PWM converter not Confucian to modify, just add a number of components, can realize the double transformation method of the functions of: steady dc voltage, the primary and secondary isolation, implementation to reduce harmonic current and improve power factor.
3. Double transformation method
Adopting two converter for steady dc output voltage and improving power factor.The converter design degrees of freedom, is to reduce the harmonic current and improve power factor of the ideal circuit.
4. Part of the smooth way
This way is to use a combination of passive components to extend the current conduction Angle, suppress harmonic current.