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Thesis Shaoshan (SS) electric locomotive power integrated cabinet developed a new type of power plug test platform , the main circuit , the test object ( SCR trigger board and chopping board ) design to simulate the working environment , and by changing the its input voltage , and provide the corresponding display instrument to observe the output voltage , for detecting whether the object to be tested to meet the design requirements . The cabinet 's main power circuit for the half-controlled bridge rectifier circuit , input AC voltage of the railway system , the rectified voltage output by the reactor , capacitor filter , to charge the battery and control circuit power supply to the locomotive . Trigger plate (Z158) by the synchronization signal , power supply , voltage regulator and phase shift trigger other sectors , synchronous phase shift control technology and SCR technology , with input over- voltage protection, output overload protection , output voltage stabilized at 110V. By adjusting the input voltage of the regulator to change the trigger plate , the observation of the output is stable , in order to detect whether the trigger plate having a regulator function ; by adjusting the feedback current , observing whether the overcurrent protection function . Chopping board (Z157, Z33) using pulse width modulation (PWM) switching power supply technology , the operating frequency of 100kHz, with input , output over-current , over- voltage and undervoltage protection functions . Output performance test of the chopping board with two resistors in parallel . When one resistor is disconnected , the output of the rated current , when the resistor is closed in order to over-current output , and then detecting whether or not to implement overcurrent protection . Analog signals need to detect a total of 10 channels , including two voltage values ??on the main circuit , chopping board (Z157) load on 3 15V, 24V and 48V output voltage value , as well as a chopping board (Z33) load on 5V ± 15V and ± 24V output voltage value . Choose single-chip 8 - bit 16-channel A / D converter chip . Microprocessor selected the 8K ROM 256B RAM Atmel89C52 chip expanded to include 8255A parallel I / O port chips , the 6264RAM memory chips , 8279 programmable keyboard and display the dedicated interface chip latches 74LS373, address decoder 74LS138 divider 74LS74 constituting the computer system . LED digital display , keyboard , printer interface is needed in order to complete the human-computer interaction .
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