The power module system structure diagram as shown in Figure 220, it can be seen that the 1 V AC voltage signal input, first through the filter circuit module, and then sub channels to achieve AC DC voltage signal, through the DC DC/ converter is 12 V and V 10:1 DC voltage signal, and then through the V converter to get 23 +9 DC voltage signal, and the use of DC voltage integrated voltage regulator V +12 and V +9 voltage, V +5 as a reference signal, while the control circuit to provide a positive voltage. Control circuit is mainly divided into control circuit and over voltage protection circuit, control circuit is mainly used to achieve the control of the output voltage of the control, and over voltage protection circuit is mainly used to achieve the protection of over voltage, play a necessary role in the protection of three DC/DC.
1) design objectives.
The design target of the module is AC/DC power supply module, the input voltage is 220 Hz V/50 AC input, the output DC voltage is 12 V, V +5, V +9 and V. +6
(2) filtered rectifier circuit.
In order to filter out the interference in the circuit, the power input is 410-3/02 SCHAFFNER, the rated current of the filter is 3 A, the maximum operating voltage is 250 V, the frequency is Hz -25, the operating temperature is ~+100, and the average time is 675000 hours. In this power module, the filter is needed for each voltage regulator module, reference source and the output terminal of the DC voltage, so the selection of the electrolytic capacitor and electrolytic capacitor value is from 47 V to 1000 V F/16.
Rectifier bridge is selected according to the different of the rectifier circuit is divided into 220 kinds, one is the two V AC rectifier for 300 V DC circuit, the use of KBPC 108 rectifier bridge, the input voltage of V 50~1000, the input current is 3 A, used to achieve high voltage rectifier.
The other is low voltage rectification, in this circuit, the first is the 220V after the 10:1 AC power transformer, the use of rectifier bridge rectifier, the output DC voltage of 23 V.
(3) DC/DC circuit design.
In order to obtain a stable and reliable 12 V and V +5 DC voltage, the high voltage DC output of the DC/DC module is implemented in the DC/DC circuit. At the low voltage side, the V and V +9 output are achieved by using 23 V F/25 and +12 output at the input and output of each module, and the electrolytic capacitor is filtered by 100 V F/25 and 47 V respectively. At the high voltage side, three + 12 V and V +5 DC voltage are generated, and the output of the three voltage signals can be controlled by the external interface. Therefore, the VI-J61-IZ, VI-J61-IY and VI-J60-IX power supply module of VICOR is used to realize the output of 12 V and V +5. The power input of the three modules is connected with 300 V DC power supply, and the high precision of 12 V and V +5 voltage is obtained. The output control of DC/DC is required, and the In Gate of the three power modules is controlled, and the schematic diagram of the three DC/DC circuit is shown in Figure 2. In Figure 2, when the control signal is high, VT1, VT2 and VT3 work, the DC/DC 2 is not working, DC/DC and +5V are not working, and the control signal is low, VT2, VT3 and VT1 are not working, at this time DC/DC are normal, 12 V +5 and V 12V voltage output.
(4) DC voltage control circuit.
The schematic diagram of the DC voltage control circuit is shown in figure 3. The circuit is composed of two parts, which are over voltage protection circuit and the external voltage control circuit. Over voltage protection circuit mainly refers to when the input voltage is too high (or low) to produce more than (less than) 300 V after a certain percentage of the voltage, after conditioning circuit to make the voltage comparator MAX973 voltage jump, so as to change the output of the control signal, resulting in the In Gate DC/DC terminal voltage jump, and then make DC/DC stop working. The external voltage control circuit refers to the output voltage of the output terminal of the control signal changes when the external control signal input terminal is changed, thereby changing the voltage of the Gate In DC/DC, making the DC/DC stop (or start) work.
When the external control signal input is low at ordinary times, NAND circuit trigger output to a high level, at this time the counter is cleared, after counting trigger circuit and the inverter inverting control signal output for the high level so as to further verify the three DC-DC does not work, the corresponding DC / DC working indicator light does not shine. When the external control signal input is high at ordinary times, NAND circuit trigger output to a low level. At this time, the counter starts to count, after counting trigger circuit and the inverter inverting control signal output low level, so as to further verify the three DC-DC normal work and + 12 V and + 5 V output voltage, DC / DC indicator lights.
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