CN208548824U - A kind of switch power source output voltage overvoltage crowbar - Google Patents
A kind of switch power source output voltage overvoltage crowbar Download PDFInfo
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- CN208548824U CN208548824U CN201820935960.0U CN201820935960U CN208548824U CN 208548824 U CN208548824 U CN 208548824U CN 201820935960 U CN201820935960 U CN 201820935960U CN 208548824 U CN208548824 U CN 208548824U
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- circuit
- optocoupler
- power supply
- pwm
- output voltage
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Abstract
The utility model discloses a kind of switch power source output voltage overvoltage crowbars.One end of its protection circuit is connect with AC-DC conversion circuit; the other end of the protection circuit is connect with DC output circuit, specifically includes following content: optocoupler phototriode end pulls up power supply circuit, PWM IC vcc power supply circuit, Phototube Coupling optocoupler, PWM IC vcc breaking circuit, output voltage sampling and optocoupler power supply circuit and one-way SCR circuit.The beneficial effects of the utility model are: preventing damage rear class electrical equipment, load equipment is protected；It is precisely controlled, outer member is few, and structure simplifies, and cost advantage is obvious.
Description
Technical field
The utility model relates to digital lighting power supply correlative technology fields, refer in particular to a kind of switch power source output voltage mistake
Voltage protection circuit.
Background technique
Switch power source output voltage is excessively high, and institute's bringing onto load equipment excessive pressure damages and power source internal can be caused to damage.
Utility model content
The utility model be in order to overcome the above deficiencies in the prior art, provide a kind of protection output loading and
The switch power source output voltage overvoltage crowbar of power supply.
To achieve the goals above, the utility model uses following technical scheme:
One end of a kind of switch power source output voltage overvoltage crowbar, the protection circuit is connect with AC-DC conversion circuit,
The other end of the protection circuit is connect with DC output circuit, specifically includes following content: the pull-up power supply of optocoupler phototriode end
Circuit, PWM IC vcc power supply circuit, Phototube Coupling optocoupler, PWM IC vcc breaking circuit, output voltage sampling and optocoupler supply
Circuit and one-way SCR circuit, optocoupler phototriode end pull up one end and the AC-DC conversion circuit of power supply circuit
The other end of connection, optocoupler phototriode end pull-up power supply circuit is connect with Phototube Coupling optocoupler, the PWM IC
One end of vcc power supply circuit is connect with AC-DC conversion circuit, the other end and PWM IC of the PWM IC vcc power supply circuit
The connection of vcc breaking circuit, the PWM IC vcc breaking circuit connect with Phototube Coupling optocoupler, the output voltage sample and
One end of optocoupler power supply circuit is connect with DC output circuit, the other end and light of the output voltage sampling and optocoupler power supply circuit
It is electrically isolated optocoupler connection, one end of the one-way SCR circuit is sampled with output voltage and optocoupler power supply circuit is connect, described
The other end of one-way SCR circuit is connect with DC output circuit.
Wherein: optocoupler phototriode end pull-up power supply circuit provides AC-DC conversion circuit to Phototube Coupling optocoupler defeated
Enter electric current；PWM IC vcc power supply circuit is turned off for providing voltage to PWM IC and PWM IC vcc in AC-DC conversion circuit
Circuit work；Phototube Coupling optocoupler is transmitted to primary side for secondary output end voltage change signal to be transformed into optical signal, drives
The movement of dynamic PWM IC vcc breaking circuit；PWM IC vcc breaking circuit is driven by Phototube Coupling optocoupler, goes to close PWM
IC vcc power supply circuit；Output voltage sampling and optocoupler power supply circuit sample the output voltage variation of DC output circuit, and will
Sampled voltage signal triggers the conducting of one-way SCR circuit, goes the brightness change for changing Phototube Coupling optocoupler.
When output voltage is more than setting value, which drags down the power supply of PWM IC, so that IC is closed PWM defeated
Out, electric power output voltage persistently reduces, and enters hiccup mode, output voltage can be limited to the range of certain safety value
It is interior, to prevent damage rear class electrical equipment, protect load equipment；And the threshold value of this over-voltage protection point can be set, and reach essence
Quasi- control, while the circuit external element is few, structure simplifies, and cost advantage is obvious.
The beneficial effects of the utility model are: preventing damage rear class electrical equipment, load equipment is protected；It is precisely controlled, outside
Portion's element is few, and structure simplifies, and cost advantage is obvious.
Detailed description of the invention
Fig. 1 is the structural block diagram of the utility model；
Fig. 2 is the circuit diagram of the utility model one kind；
Fig. 3 is the circuit diagram of AC-DC conversion circuit；
Fig. 4 is the circuit diagram of DC output circuit；
Fig. 5, Fig. 6 are the circuit diagrams of optocoupler phototriode end pull-up power supply circuit；
Fig. 7 is the circuit diagram of Phototube Coupling optocoupler；
Fig. 8 is the circuit diagram of PWM IC vcc power supply circuit；
Fig. 9 is the circuit diagram of PWM IC vcc breaking circuit；
Figure 10 is the circuit diagram of output voltage sampling and optocoupler power supply circuit and one-way SCR circuit.
In figure: 1.AC-DC conversion circuit, 2.DC output circuit, 3. optocoupler phototriode ends pull up power supply circuit, 4. light
It is electrically isolated optocoupler, 5.PWM IC vcc power supply circuit, 6.PWM IC vcc breaking circuit, the sampling of 7. output voltages and optocoupler power supply
Circuit, 8. one-way SCR circuits.
Specific embodiment
The utility model is further described with reference to the accompanying drawings and detailed description.
In embodiment as described in Figure 1, a kind of switch power source output voltage overvoltage crowbar, one end of the protection circuit
It is connect with AC-DC conversion circuit 1, the other end of the protection circuit is connect with DC output circuit 2, specifically includes following content: light
Coupling phototriode end pulls up power supply circuit 3, PWM IC vcc power supply circuit 5, Phototube Coupling optocoupler 4, PWM IC vcc shutdown
Circuit 6, output voltage sampling and optocoupler power supply circuit 7 and one-way SCR circuit 8, optocoupler phototriode end pull-up power supply electricity
The one end on road 3 is connect with AC-DC conversion circuit 1, and optocoupler phototriode end pulls up the other end and Phototube Coupling of power supply circuit 3
Optocoupler 4 connects, and one end of PWM IC vcc power supply circuit 5 is connect with AC-DC conversion circuit 1, PWM IC vcc power supply circuit 5
The other end is connect with PWM IC vcc breaking circuit 6, and PWM IC vcc breaking circuit 6 is connect with Phototube Coupling optocoupler 4, output electricity
Pressure sampling and one end of optocoupler power supply circuit 7 are connect with DC output circuit 2, output voltage sample and optocoupler power supply circuit 7 it is another
One end is connect with Phototube Coupling optocoupler 4, and one end of one-way SCR circuit 8 connects with output voltage sampling and optocoupler power supply circuit 7
It connects, the other end of one-way SCR circuit 8 is connect with DC output circuit 2.
As shown in figure 3, the elements such as U101, TB1-C, Q101, D201A form AC-DC conversion circuit, nominal value will be inputted
230V alternating current is converted into direct current 24V.As shown in figure 4, E203, E204 are low ESR electrolytic capacitor, for carrying out to alternating component
Filtering, during mos conducting, to load supplying.R204, R205 are false load, serve as load in power supply zero load, maintain output
Stablize.As shown in Figure 5, Figure 6, VDD R103, R104 form high-voltage starting circuit, and R15 is connected to R104, give optocoupler photosensitive three
Pull-up power supply is done at pole pipe end, and C3 does ac filter, and PC100-B is optocoupler phototriode part.As shown in fig. 7, PC100 is light
It is electrically isolated optocoupler.PC100-B is optocoupler phototriode part, and PC100-A is photodiode part, when PC100-A flows through
Electric current increases, and brightness also will increase, and the conducting depth of PC100-B becomes larger therewith, and the E pole tension of PC100-B can also become larger.Such as
Shown in Fig. 8, the biasing winding of D102, R113, D6, CE101, TB1-C form PWM IC vcc power supply circuit VPCC.Give IC U1
Stable 15V power supply is provided, U1 work is maintained.As shown in figure 9, Q2, Q3, Q11, R16, Q4 composition PWM IC vcc shutdown electricity
Road.Q2 is NPN triode, and the pole B is connected to the pole E of PC100-B.When the E pole tension of PC100-B reaches the conducting voltage of the pole Q2B,
Q2 conducting, the pole Q3B are pulled low, and Q3 is PNP triode, and the pole B is pulled down to 0.3V hereinafter, the pole Q3C, E is connected.Vdd voltage passes through
The pole R11, Q3C, E to 1 end of Q4, Q4 are N-channel mos, and 1 end reaches 2V or more, 2, the 3 ends conducting of Q4, and VPCC is pulled low to ground,
For U1 because power supply VCC is lower than starting voltage, U1 turns off PWM.As shown in Figure 10, output voltage 24V by R12 be connected to
PC100-A, D5 are one-way SCR, and ZDS1, R13, R14, C2 are output voltage sampling circuit.Output voltage is more than design value,
ZDS1 conducting, R13 and R14 form bleeder circuit, and R13 is connect at the R14 partial pressure and pole G of D5, when D5G pole tension reaches 1.5V
More than, the pole D5A, K conducting, the light emitting diode of PC100-A is also switched on, and there is electric current to flow through, lumination of light emitting diode, PC100-B
Phototriode conducting, trigger PWM IC vcc breaking circuit.The PWM of U1 is turned off, and output voltage reduces, the pole D5A, K stream
Overcurrent decreases, and when this electric current is lower than the maintenance electric current of D5, D5 is turned off, and no current flows through in PC100-A.PC100-B
Phototriode shutdown, PWM IC vcc breaking circuit is also turned off.The VCC voltage amplitude of U1, power up output.If
Output overvoltage has been eliminated extremely, and output voltage is normal.If output overvoltage still remains extremely, hiccup mode, protection can be entered
Rear class charging equipment and power supply.
Nominal value 230V alternating current is transformed into mark by AC-DC conversion circuit 1 in the utility model embodiment as shown in Figure 2
Title value 24V direct current.The direct current containing alternating component after rectifying tube is filtered into direct current by DC output circuit 2, and
The each turn-on cycle of mos provides energy to external loading.Transformer is biased winding induction electric by PWM IC vcc power supply circuit 5
Gesture rectification, the stable DC for being filtered into amplitude 15V are powered to PWM IC, this circuit is by PWM IC vcc breaking circuit control
System.It is photosensitive by the high-voltage starting circuit offer inflow in AC-DC conversion circuit 1 that optocoupler phototriode end pulls up power supply circuit 3
The electric current of triode.Phototube Coupling optocoupler 4 is isolation optocoupler element, and when photodiode brightness becomes larger, phototriode is led
Logical depth increases, and phototriode E pole tension becomes larger, and goes the triode movement in driving PWM IC vcc breaking circuit 6.PWM
The pole triode B is connected to the pole phototriode E in IC vcc breaking circuit 6, and after B pole tension reaches conducting voltage, triode is led
It is logical, go driving mos that PWM IC vcc power supply circuit 5 is pulled down to ground, when Vcc voltage is lower than IC starting voltage, IC PWM shutdown,
Output voltage decreases.In output voltage sampling and optocoupler power supply circuit 7, when output voltage is higher than design value, sampling electricity
The voltage that road is adopted reaches the pole one-way SCR G trigger voltage, controlled silicon conducting；Output voltage sampling simultaneously and optocoupler power supply electricity
The electric current that road 7 is input to 4 photodiode part of Phototube Coupling optocoupler increases, and photodiode brightness increases with it, and photosensitive three
Depth also synchronous increase is connected in pole pipe.The one-way SCR pole circuit 8G is sampled by output voltage and optocoupler power supply circuit 7 triggers
Conducting, when output voltage reduces, and flows into one-way SCR A, K electrode current lower than electric current is maintained, one-way SCR shutdown.
When pressure stabilizing loop breaks down or causes output overvoltage phenomenon since user's operation is improper inside Switching Power Supply,
Output overvoltage protection circuit, in the range of output voltage being limited to certain safety value, to prevent damage rear class electrical equipment.
This circuit over-voltage protection point can be altered according to customer demand, and be changed conveniently, versatile.Output over-voltage protection value can be with
Precisely setting, while the circuit external element is few, structure simplifies, and cost advantage is obvious.
Claims (1)
1. a kind of switch power source output voltage overvoltage crowbar, one end and AC-DC conversion circuit (1) of the protection circuit are even
It connects, the other end of the protection circuit is connect with DC output circuit (2), characterized in that specifically includes following content: optocoupler photosensitive three
Pole pipe end pulls up power supply circuit (3), PWM IC vcc power supply circuit (5), Phototube Coupling optocoupler (4), PWM IC vcc shutdown electricity
Road (6), output voltage sampling and optocoupler power supply circuit (7) and one-way SCR circuit (8), on optocoupler phototriode end
The one end of power supply circuit (3) is drawn to connect with AC-DC conversion circuit (1), optocoupler phototriode end pulls up power supply circuit (3)
The other end connect with Phototube Coupling optocoupler (4), one end of the PWM IC vcc power supply circuit (5) and AC-DC conversion circuit
(1) it connects, the other end of the PWM IC vcc power supply circuit (5) is connect with PWM IC vcc breaking circuit (6), described
PWM IC vcc breaking circuit (6) is connect with Phototube Coupling optocoupler (4), the output voltage sampling and optocoupler power supply circuit (7)
One end connect with DC output circuit (2), the other end and Phototube Coupling of output voltage sampling and optocoupler power supply circuit (7)
One end of optocoupler (4) connection, the one-way SCR circuit (8) is sampled with output voltage and optocoupler power supply circuit (7) is connect, institute
The other end for stating one-way SCR circuit (8) is connect with DC output circuit (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820935960.0U CN208548824U (en) | 2018-06-18 | 2018-06-18 | A kind of switch power source output voltage overvoltage crowbar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820935960.0U CN208548824U (en) | 2018-06-18 | 2018-06-18 | A kind of switch power source output voltage overvoltage crowbar |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208548824U true CN208548824U (en) | 2019-02-26 |
Family
ID=65422834
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820935960.0U Active CN208548824U (en) | 2018-06-18 | 2018-06-18 | A kind of switch power source output voltage overvoltage crowbar |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208548824U (en) |
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2018
- 2018-06-18 CN CN201820935960.0U patent/CN208548824U/en active Active
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