Summary of the invention
In view of the technical drawbacks of the prior art, it is an object of the present invention to provide a kind of ATX power supply maintenance conditions
Circuit.
The technical solution adopted to achieve the purpose of the present invention is:
A kind of ATX power supply maintenance conditions circuit, including the transformer T1 that primary side is connect with firewire L with zero curve N respectively, with
The rectifier bridge U1 of the primary side connection of transformer T1, rectifier bridge U1 are connect with VCC voltage;It further include having relay K, relay K
Coil connect respectively with 5V voltage and relay K control circuit, the normal open switch of relay K respectively with buzzer B1 and 5V
Voltage connection, is grounded after buzzer B1 is in parallel with transistor D1, the normally closed switch of relay K respectively with load S and time after
Electric appliance KT connection, normally closed switch and concatenated resistance R1 on firewire L, the R2 connection of relay K.
The coil of the time relay KT connects the collector of triode Q4, and the base stage of triode Q4 is with comparator U3_1's
Output is connected through resistance R13, and the positive input terminal of comparator U3_1 is connect with reference voltage RVEF, negative input end and the control of PSON signal
The output end of circuit processed connects, and the collector of triode Q4 is connect through resistance 12 with 5V voltage.
The PSON signal control circuit includes triode Q1 and comparator U3_2, the negative input end warp of comparator U3_2
R20 is connect with reference voltage RVEF, positive input terminal is connect through resistance R21 with PG signal generating circuit, the output of comparator U3_2
End is connect through resistance R11 with the base stage of triode Q1, and the emitter ground connection of triode Q1, base stage is the output end of PSON signal.
The relay K control circuit includes the thyristor D2 that output is connect with the coil K_1 of relay K, thyristor
The input of D2 is grounded after connecting with the emitter of triode Q3, and the base stage of triode Q3 is through the defeated of resistance R14 and comparator U3_1
It connects out, triode Q3 collector connects 5V voltage, and comparator U3_1 positive input terminal is connect with the output end of voltage stabilizing chip U2, pressure stabilizing
The input of chip U2 terminates VCC voltage, and the negative input end of comparator U3_1 is grounded after resistance R4.
ATX power supply maintenance conditions circuit of the invention, when fault causes electric current to increase suddenly, protection circuit rises automatically
Dynamic circuit breaker electric protection;Work as circuit amount working properly with testing circuit, be automatically converted to test mode, the band of test ATX power supply carries energy
Power.The ATX power supply maintenance conditions circuit had not only effectively prevented security risk in maintenance work, but also had carried out aging survey to power supply
Examination.
Specific embodiment
The present invention is described in further detail below in conjunction with the drawings and specific embodiments.It should be appreciated that described herein
Specific embodiment be only used to explain the present invention, be not intended to limit the present invention.
Referring to shown in Fig. 1-6, a kind of ATX power supply maintenance conditions circuit, comprising:
The transformer T1 that primary side is connect with firewire L with zero curve N respectively, the rectifier bridge being connect with the primary side of transformer T1
U1, rectifier bridge U1 are connect with VCC voltage;It further include having relay K, the coil of relay K is controlled with 5V voltage and relay K respectively
Circuit connection processed, the normal open switch of relay K are connect with buzzer B1 and 5V voltage respectively, and buzzer B1 and transistor D1 are simultaneously
Be grounded after connection, the normally closed switch of relay K respectively with load the S and time relay KT connect, the normally closed switch of relay K and
Divider resistance R1, the R2 connection being connected on the firewire L of 220V route, there are also ammeters by firewire L.
Wherein, the coil of time relay KT connects the collector of triode Q4, the base stage and comparator U3_1 of triode Q4
Output connected through resistance R13, the positive input terminal of comparator U3_1 is connect with reference voltage RVEF, negative input end and PSON signal
The output end of control circuit connects, and the collector of triode Q4 is connect through resistance 12 with 5V voltage.
Wherein, the PSON signal control circuit includes triode Q1 and comparator U3_2, and bearing for comparator U3_2 is defeated
Enter end connect through R20 with reference voltage RVEF, positive input terminal is connect through resistance R21 with PG signal generating circuit, comparator U3_2
Output end connect through resistance R11 with the base stage of triode Q1, the emitter of triode Q1 ground connection, base stage is the defeated of PSON signal
Outlet.
Wherein, the relay K control circuit includes the thyristor D2 that output is connect with the coil K_1 of relay K, brilliant
The input of brake tube D2 is grounded after connecting with the emitter of triode Q3, and the base stage of triode Q3 is through resistance R14 and comparator U3_1
Output connection, triode Q3 collector connects 5V voltage, and comparator U3_1 positive input terminal is connect with the output end of voltage stabilizing chip U2,
The input of voltage stabilizing chip U2 terminates VCC voltage, and the negative input end of comparator U3_1 is grounded after resistance R4.
It in the present invention, is started by the PG signal control relay K of ATX power supply, the limit in main line is shorted by relay K
Leakage resistance.
In the present invention, the T1_1 in Fig. 1 is connected with T1_2 with the T1_1 in Fig. 2 with T1_2, the KT_3 and KT_4 in Fig. 1 and
KT_3 in Fig. 6 is connected with KT_4, and the K_1 in Fig. 1 is connected with the K_1 in Fig. 3, and the PSON in the PSON and Fig. 6 in Fig. 5 connects
It connects, the VREF in Fig. 4 is reference voltage, is connect with the VREF in other figures, and the VREF in Fig. 4 is 2.5V voltage, as benchmark
Voltage.
In the present invention, current limliting and partial pressure are played the role of in concatenated resistance R1 and R2 series connection on firewire, and transformer T1 is depressured,
Voltage VCC is obtained by rectifier bridge U1, the value for exporting VCC is 12V, and output VCC voltage is obtained stable electricity by voltage stabilizing chip U2
5V is pressed, the positive input terminal of comparator U3-1 is given to, stable voltage 5V send defeated to bearing for comparator U3-1 through resistance R3, R4 partial pressure
Enter end, under normal circumstances, resistance R3, R4 divide to obtain 6V, and comparator U3_1 exports low level, and triode Q3 is not open-minded, after
The coil of electric appliance K must not be electric, and the normally closed switch of relay K is in close state, and the firewire L of 220V alternating current is connected with zero curve N
ATX power supply is referred to load S, load S.ATX power supply works normally at this time, exports PG signal, 3V or so;Also export PSON
Signal 4.5V or so;PG voltage is higher than benchmark VREF at this time, and comparator U3_2 exports high level, and triode Q1 is open-minded, PSON
Voltage pull-down, PSON voltage is lower than benchmark VREF at this time, and comparator U3_3 exports high level, and triode Q4 is open-minded, time relay
Device KT coil energized action, normal open switch become normally off, and firewire L skips resistance R1 and R2 and is directly connected to load, give ATX
Power supply full-load operation creates conditions, and ATX power supply enters band and carries test phase.
According to ATX power circuit output characteristic, by by the relevant voltage output end+5V ,+12V ,+3.3V of ATX power supply and
+ 5VSB concatenates DC load (using nichrome resistance) connection of corresponding different resistance values, can be detected the corresponding defeated of ATX power supply
Out the case where circuit.
When short circuit exception occurs in load, the end T1_1 voltage is reduced, and the voltage VCC after rectifier bridge U1 rectification is reduced,
Resistance R3, R4 partial pressure is lower than 5V, and comparator U3_1 exports high level at this time, and triode Q3 is open-minded, and thyristor D2 is open-minded, relay
K coil obtains electric, and normally closed switch becomes normally open, and firewire L is disconnected, and 220V alternating current not powering load plays a protective role.
Normal open switch becomes normally off at this time, and light emitting diode D1 is bright, and buzzer B1 issues alarm, indicates that load has exception.
The above is only a preferred embodiment of the present invention, it is noted that for the common skill of the art
For art personnel, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications
Also it should be regarded as protection scope of the present invention.