Inverter welding machine working principle is the three-phase frequency (50Hz) AC network voltage, first rectified and filtered by the input rectifier, into DC, and then through the alternating switching action of high-power switching electronic components (thyristor SCR, transistor GTR, FET MOSFET or IGBT), inverted into a few kHz ~ dozens of kHz intermediate-frequency AC voltage, and at the same time by transformer At the same time by the transformer down to a few tens of V voltage suitable for welding, and then rectified and filtered by the reactance output quite smooth DC welding current.
Welding circuit is closed, because the circuit is closed to make the current in the entire closed circuit is equal everywhere; due to the resistance of each place is not the same, especially in the unfixed contact at the maximum resistance, this resistance is called contact resistance in physics.
According to the law of thermal effect of electric current (also known as Joule's law), Q = I2Rt can be seen, the current is equal, the greater the resistance of the part of the heat is higher, electric welding in the welding electrode contact with the welded metal body in contact with the contact resistance is the largest, then the heat generated in this part of the nature of the most, the electrode is a low melting point of the alloy, soon to be melted, the melted alloy welding electrode The core of the melted alloy welding rod is coated with the object to be welded after cooling, the welding object is bonded to a piece.
Because the inverter welder is a typical switching power supply (output characteristics and has a great deal of characteristics), the output power is large, the working environment changes, so the requirements of the quality of the components to be good, so as to ensure that the work of the stability of the type, long life.
The role of the driver board is to amplify the modulated drive signals sent from the control board to drive the power switching devices, and at the same time to isolate the main circuit switching devices from the high voltage and current of the control board.
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The function of the control board is to collect the current and voltage signals from the output of the welder according to the current and voltage parameters given by the panel, and control the PWM pulse generating circuit to generate suitable driving pulses to the driver board after comparing and calculating respectively.
Extended information
Inverter arc welding power supply, also known as arc welding inverter, is a new type of welding power supply, this power supply is a three-phase industrial frequency AC network voltage, first rectified and filtered by the input rectifier into DC, and then through the high-power switching electronic components of the alternate switching effect, inverted into a few kHz ~ tens of kHz The intermediate frequency AC voltage is reduced to several tens of V voltage suitable for welding by the transformer, and then rectified again and filtered by the reactance to output a smooth DC welding current.
Baidu Encyclopedia - Inverter Welding Machines