CN223261682U - Light source and main board driving circuit of projector - Google Patents
Light source and main board driving circuit of projectorInfo
- Publication number
- CN223261682U CN223261682U CN202423057418.4U CN202423057418U CN223261682U CN 223261682 U CN223261682 U CN 223261682U CN 202423057418 U CN202423057418 U CN 202423057418U CN 223261682 U CN223261682 U CN 223261682U
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- CN
- China
- Prior art keywords
- light source
- power supply
- driving circuit
- main board
- circuit
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
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- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The utility model discloses a light source and a main board driving circuit of a projector, which comprises a rectifying circuit, a light source driving circuit, a main board driving circuit and an isolation transmission element, wherein the light source driving circuit is a non-isolation power supply, the main board driving circuit is an isolation power supply, and the main board driving circuit controls the working state of the light source driving circuit through the isolation transmission element, so that the safety of the main board and an I/O port of the projector is ensured, the high efficiency of the light source driving circuit is also considered, and the power adapter is a low-cost and high-efficiency power adapter design scheme and is suitable for household LED projectors and similar electrical products.
Description
Technical Field
The present utility model relates to projection devices, and more particularly to a light source and a motherboard driving circuit for a projector.
Background
In order to ensure the safety of the main board and the I/O port of the projector, the current projector adopts an isolated power supply design (i.e. the input end and the output end are not commonly grounded) for the light source driving circuit and the main board driving circuit. It is known that an isolated power supply generally needs to use an isolated element such as a transformer, although its stability and safety are high, the hardware cost is relatively high due to the need to use an isolated element such as a transformer, and the efficiency is not as high as that of a non-isolated power supply due to the energy conversion transmission loss, whereas a non-isolated power supply (i.e., the input end and the output end are commonly grounded) has low safety, but it does not need to use an isolated element such as a transformer, resulting in relatively low hardware cost, and its efficiency is also high due to the absence of energy conversion transmission loss.
It is apparent that the light source driving circuit and the main board driving circuit of the projector in the prior art adopt an isolated power supply design, and the safety is improved, but the efficiency is also sacrificed.
Disclosure of utility model
In order to overcome the defects of the prior art, the utility model provides a light source and a main board driving circuit of a projector, which are compatible with safety and efficiency.
The technical scheme adopted for solving the technical problems is as follows:
A light source and main board driving circuit of projector includes:
The rectifying circuit has input connected to live wire ACL and zero wire ACN of the mains supply and output connected to the positive pole DC+ of the DC power supply and ground GND1.
Light source driving circuit: the LED projector is a non-isolated power supply, the input end of the LED projector is connected with the output end of the direct current power supply, and the output end of the LED projector is connected with the projector light source LED and is provided with a light source driving control end.
The main board driving circuit is an isolated power supply and comprises an isolated conversion element, wherein the primary side of the isolated conversion element is connected with an isolated power supply control circuit and the output end of the direct current power supply, and the secondary side of the isolated conversion element is used as the positive output end of the isolated power supply and the ground GND2 to supply power to the main board of the projector.
And the positive electrode of the input end of the isolation transmission element is connected with the control signal output end EN of the projector main board, the negative electrode of the isolation transmission element is connected with the reference ground GND2 of the isolation power supply, the output positive electrode of the isolation transmission element is connected with the light source driving control end, and the negative electrode of the isolation transmission element is connected with the reference ground GND1.
As a further development of the utility model, the reference ground GND1 and the reference ground GND2 are isolated by a capacitance CY 1.
As a further improvement of the utility model, the isolation transmission element is connected with the light source driving control end through a field effect transistor Q1.
As a further improvement of the utility model, the light source driving circuit comprises a constant current driving chip U2, and the light source driving control end is a control input end of the constant current driving chip U2.
As a further improvement of the utility model, the isolation conversion element is a transformer T1, a primary side of the transformer T1 is provided with a primary side winding and a feedback winding, a secondary side of the transformer T1 is provided with a secondary side winding, one end of the primary side winding is connected with a positive pole DC+ of the direct current power supply, the other end of the primary side winding is connected with an output end of the isolation power supply control circuit, one end of the feedback winding is a feedback voltage input end of the feedback voltage end of the isolation power supply control circuit, the other end of the feedback winding is connected with the reference ground GND1, one end of the secondary side winding is a positive pole output end of the isolation power supply, and the other end of the secondary side winding is the reference ground GND2.
As a further improvement of the utility model, the isolated power supply control circuit comprises a primary side feedback switch power supply chip U1, and the feedback voltage input end of the primary side feedback switch power supply chip U1 is connected with the feedback voltage end.
As a further improvement of the utility model, the isolation transmission element is a photo-coupler IC1, and a zener diode ZD1 is connected between the positive electrode of the output end of the photo-coupler IC1 and the ground GND 1.
As a further improvement of the utility model, the rectifying circuit comprises a rectifying bridge DB1, wherein the input end of the rectifying bridge DB1 is connected with a live wire ACL and a zero line CAN of the commercial power, the output end is a positive pole dc+ of the direct current power supply and a reference ground GND1, a piezoresistor MOV1 is connected between the live wire ACL and the zero line CAN, the live wire ACL is connected with a fuse F1 in series, the zero line CAN is connected with a thermistor NTC1 in series, and a polar capacitor C4 is connected between the positive pole dc+ and the reference ground GND 1.
As a further improvement of the utility model, a filter circuit C5R12 formed by connecting a polar capacitor C5 and a resistor R12 in parallel is connected between the output ends of the light source driving circuit.
As a further improvement of the utility model, a filter circuit C1R1 formed by connecting a polar capacitor C1 and a resistor R1 in parallel is connected between the output ends of the main board driving circuit.
The utility model has the beneficial effects that the light source driving circuit is a non-isolated power supply, the main board driving circuit is an isolated power supply, and the main board driving circuit controls the working state of the light source driving circuit through the isolated transmission element, thereby ensuring the safety of the main board and the I/O port of the projector, also taking into account the high efficiency of the light source driving circuit, and being a design scheme of a power adapter with low cost and high efficiency, and being suitable for household LED projectors and similar electrical products.
Drawings
The utility model will be further described with reference to the drawings and examples.
Fig. 1 is a schematic diagram of the principles of the present utility model.
Fig. 2 is a schematic circuit diagram of the present utility model.
Detailed Description
Referring to fig. 1, a light source and a main board driving circuit of a projector includes a rectifying circuit, a light source driving circuit, a main board driving circuit and an isolation transmission element, wherein the rectifying circuit converts commercial alternating current into high-voltage direct current, and an output end of the high-voltage direct current is a positive pole dc+ of a direct current power supply and a reference ground GND1, namely a negative pole DC-of the direct current power supply.
The light source driving circuit is a non-isolated power supply, the input end and the output end are grounded together, the main board driving circuit is an isolated power supply, and the input end and the output end are not grounded together. The projector light source LED has no external circuit and does not need to consider safety, so that a non-isolated power supply with high efficiency and no transformer is adopted. The projector main board is provided with a plurality of external I/O ports, and the security of the main board and the I/O ports is ensured by adopting an isolated power supply. The projector main board outputs a control signal EN to the isolation transmission element, the working state of the light source driving circuit is controlled by the isolation transmission element, and the isolation transmission element is electrically and physically isolated, so that a good isolation protection effect can be achieved.
Referring to fig. 2, fig. 2 is a schematic circuit diagram of a typical circuit in this embodiment, where the circuit includes a rectifying circuit, a light source driving circuit, a motherboard driving circuit, and an isolation transmission element, where the isolation transmission element uses a photo-coupler IC1, and the photo-coupler IC1 is connected to a light source driving control end through a field effect transistor Q1.
In this embodiment, the light source driving circuit adopts the constant current driving chip U2, the constant current driving chip U2 adopts SIC953XC series chips, such as SIC9537CD, SIC9536CD, SIC9534CS, and the like, and the series chips are high-precision LED constant current driving chips with ultra-low system cost, and are suitable for low-power non-isolated buck LED illumination in 85 v-265 v full-voltage range, and high-precision sampling and compensation circuits are built in the light source driving circuit, so that the constant current precision within +/-5% can be achieved, and the self-adaption of output current to inductance and output voltage can be realized, thereby obtaining excellent linear adjustment rate and load adjustment rate. The 500V power MOSFET is integrated in the system, a secondary feedback circuit is not needed, a compensation circuit is not needed, and an accurate and stable self-adaptive technology is also needed, so that the peripheral structure of the system is very simple, high-precision constant current control can be realized under the conditions of small number of peripheral devices and loose parameter range, and the cost and the volume of the system are greatly saved. Pins of the SIC953XC series chip are defined as 1 pin GND, chip ground, 2 pin RADJ, an OVP regulating pin which is externally connected with a resistor to the GND and can continuously regulate the OVP point, when the voltage of the RADJ pin is less than 150mV, the system is closed, 3 pin NC, blank pin, 4 pin HV, an internal power supply pin, a bus voltage, 5 pin DRN, a drain end of an internal MOSFET, 6 pin DRN, blank pin, 7 pin ISEN, current sampling and externally connected with the resistor to ground.
In this embodiment, the isolation conversion element is a transformer T1, the isolation power supply control circuit uses a primary feedback switching power supply chip U1, the primary feedback switching power supply chip U1 uses FM3783 series chips, such as FM3783HA, FM3783BA, FM3783AA, and the like, and the series chips are low-power consumption primary feedback (PSR) switching power supply chips, in which high-power BJT transistors are integrated, and are suitable for application in isolated high-efficiency low-power consumption portable device chargers. The FM3783 series chip adopts a unique primary side feedback control technology with constant current and constant voltage functions, and a unique light-load frequency modulation technology reduces the self power consumption of the light-load chip to realize high-efficiency application. The FM3783 series chip also has an output line loss compensation technology, and ensures enough output power under high current. Pins of the FM3783 series chip are defined as a 1 pin FB, feedback voltage input, a 2 pin CS, a current sampling resistor connected between CS and GND, a 3 pin VCC, an internal power bypass capacitor connected between VCC and GND, a 4 pin E, an emitter of a built-in high-power BJT tube, a 5 pin/6 pin C, a collector of the built-in high-power BJT tube, a 7 pin GND and chip ground.
The rectifying circuit comprises a rectifying bridge DB1, the input end of the rectifying bridge DB1 is connected with a live wire ACL and a zero line CAN of the mains supply, the output end is a positive pole DC+ of the direct current power supply and a reference ground GND1, a piezoresistor MOV1 is connected between the live wire ACL and the zero line CAN, the live wire ACL is connected with a fuse F1 in series, the zero line CAN is connected with a thermistor NTC1 in series, and a polar capacitor C4 is connected between the positive pole DC+ and the reference ground GND 1. The rectification circuit converts commercial alternating current into high-voltage direct current.
The light source driving circuit comprises a constant current driving chip U2, wherein a 1 st pin of the constant current driving chip U2 is connected with a reference ground GND1 of a direct current power supply, a2 nd pin of the constant current driving chip U2 is connected with a drain electrode of a field effect tube Q1, a resistor R15 is connected between the drain electrode and a source electrode of the field effect tube Q1, a grid electrode of the field effect tube Q1 is connected with an anode of a projector light source LED through a resistor R11 and an electron R13, a 4 th pin of the constant current driving chip U2 is connected with a positive pole DC+ of the direct current power supply, a resistor R14 is connected between the 4 th pin and the positive pole DC+ of the direct current power supply, a 5 th pin of the constant current driving chip U2 is connected with a negative pole of the projector light source LED through an inductor L1, a 6 th pin of the constant current driving chip U2 is a null pin, a voltage stabilizing diode D7 and a voltage stabilizing diode D8 are connected between the 4 th pin and the 5 th pin, and the 7 th pin of the constant current driving chip U2 is connected with a resistor R16 and the resistor R17 in parallel. And a filter circuit C5R12 formed by connecting a polar capacitor C5 and a resistor R12 in parallel is connected between the output ends of the light source driving circuit.
The main board driving circuit comprises a transformer T1 and a primary side feedback switching power supply chip U1, wherein a primary side of the transformer T1 is provided with a primary side winding (namely a 1 st pin and a 2 nd pin) and a feedback winding (namely a 3 rd pin and a 4 th pin), a secondary side of the transformer T1 is provided with a secondary side winding (namely a5 th pin and a6 th pin), the 1 st pin of the transformer T1 is connected with a positive pole DC+ of the direct current power supply, the 3 rd pin of the transformer T1 is connected with the reference ground GND1, the 6 th pin of the transformer T1 outputs a positive pole VOUT+ through a voltage stabilizing diode D2, the 5 th pin of the transformer T1 outputs a negative pole VOUT-, and the positive pole VOUT+ and the negative pole VOUT-are used for supplying power to a main board of the projector. The primary side feedback switch power supply chip U1 is characterized in that a resistor R7 is connected between a 1 st pin of the primary side feedback switch power supply chip U1 and a 4 th pin of the transformer T1, a current sampling resistor R8 and a current sampling resistor R9 are connected between a 2 nd pin and a 7 th pin of the primary side feedback switch power supply chip U1, a 3 rd pin of the primary side feedback switch power supply chip U1 is connected with a positive pole DC+ of a direct current power supply through a resistor R5 and a resistor R2, the 3 rd pin is grounded to a reference GND1 through a polar capacitor C3, the 3 rd pin is connected with the 4 th pin of the transformer T1 through a voltage stabilizing diode D6, and the 5 th pin and the 6 th pin of the primary side feedback switch power supply chip U1 are connected with the 2 nd pin of the transformer T1. And a filter circuit C1R1 formed by connecting a polar capacitor C1 and a resistor R1 in parallel is connected between the output ends of the main board driving circuit. The transformer T1 converts a high-voltage direct current power supply into a low-voltage direct current power supply to supply power to the projector main board, has a constant current and constant voltage function, and ensures the safety of the projector main board and the I/O port.
The isolation transmission element comprises a photoelectric coupler IC1 and a field effect transistor Q1, and a zener diode ZD1 is connected between the positive electrode of the output end of the photoelectric coupler IC1 and the ground GND 1. The 1 st pin of the photoelectric coupler IC1 is connected with a control signal EN through a resistor R4, the 2 nd pin of the photoelectric coupler IC1 is connected with a reference ground GND1 through a resistor R10, the 3 rd pin of the photoelectric coupler IC1 and a source electrode of a field effect tube Q1 are connected with the reference ground GND1, the 4 th pin of the photoelectric coupler IC1 is connected with a grid electrode of the field effect tube Q1, a zener diode ZD1 is connected between the 3 rd pin and the 4 th pin of the photoelectric coupler IC1, and the grid electrode of the field effect tube Q1 is connected with a positive electrode DC+ of a direct current power supply through a resistor R11 and a resistor R13.
The working principle is that a live wire ACL and a zero line CAN of commercial power are input into a rectifying circuit, the rectifying circuit converts alternating current into high-voltage direct current, the direct current is divided into two paths, one path of direct current supplies power to a projector main board through a main board driving circuit of an isolated power supply, the other path of direct current supplies power to a projector light source LED through a light source driving circuit of a non-isolated power supply, and the main board driving circuit controls the working state of the light source driving circuit through an isolated transmission element. The isolation transmission element adopts a photoelectric coupler IC1 as a physical isolation device, and simultaneously utilizes the characteristic that the 2 nd pin (OVP adjusting pin) of the constant current driving chip U2 is cut off at a low level to ground the 2 nd pin through the field effect tube Q1, the field effect tube Q1 is in a conducting state when the power-on state is started, the voltage of the 2 nd pin of the constant current driving chip U2 is close to zero volt, and the constant current driving chip U2 is in a non-starting working state so as to ensure a cut-off control state. When the projector main board outputs a high-level control signal EN (which can be a PWM signal), the photoelectric coupler IC1 is conducted, the voltage at two ends of the field effect tube Q1 is lower than the conducting voltage, the field effect tube Q1 is cut off, the voltage of the 2 nd pin of the constant current driving chip U2 is raised to be higher than 0.15V, and the constant current driving chip U2 enters a working starting state, so that the light source LED of the projector is driven to be lightened.
The above embodiments do not limit the protection scope of the utility model, and those skilled in the art can make equivalent modifications and variations without departing from the whole inventive concept, and they still fall within the scope of the utility model.
Claims (10)
1. The utility model provides a light source and mainboard drive circuit of projecting apparatus which characterized in that includes:
the rectification circuit is characterized in that the input end of the rectification circuit is connected with a live wire ACL and a zero wire ACN of the mains supply, and the output end of the rectification circuit is a positive electrode DC+ of the direct current power supply and a reference ground GND1;
Light source driving circuit: is a non-isolated power supply, the input end of the non-isolated power supply is connected with the output end of the direct current power supply, the output end is connected with a projector light source LED and is provided with a light source driving control end;
The main board driving circuit is an isolated power supply and comprises an isolated conversion element, wherein the primary side of the isolated conversion element is connected with an isolated power supply control circuit and the output end of the direct current power supply, and the secondary side of the isolated conversion element is used as the positive output end of the isolated power supply and the ground GND2 to supply power to the main board of the projector;
And the positive electrode of the input end of the isolation transmission element is connected with the control signal output end EN of the projector main board, the negative electrode of the isolation transmission element is connected with the reference ground GND2 of the isolation power supply, the output positive electrode of the isolation transmission element is connected with the light source driving control end, and the negative electrode of the isolation transmission element is connected with the reference ground GND1.
2. The light source and motherboard driving circuit of a projector according to claim 1, wherein the ground GND1 and the ground GND2 are isolated by a capacitor CY 1.
3. The light source and main board driving circuit of the projector according to claim 1, wherein the isolation transmission element is connected to the light source driving control terminal through a field effect transistor Q1.
4. The light source and main board driving circuit of the projector according to claim 1, wherein the light source driving circuit comprises a constant current driving chip U2, and the light source driving control terminal is a control input terminal of the constant current driving chip U2.
5. The light source and main board driving circuit of the projector according to claim 1, wherein the isolation conversion element is a transformer T1, a primary side of the transformer T1 has a primary winding and a feedback winding, a secondary side of the transformer T1 has a secondary winding, one end of the primary winding is connected with a positive pole dc+ of the DC power supply, the other end is connected with an output end of the isolation power supply control circuit, one end of the feedback winding is a feedback voltage input end of the feedback voltage end of the isolation power supply control circuit, the other end is connected with the reference ground GND1, one end of the secondary winding is a positive output end of the isolation power supply, and the other end is the reference ground GND2.
6. The light source and motherboard driving circuit of the projector according to claim 5, wherein the isolated power supply control circuit comprises a primary feedback switching power supply chip U1, and a feedback voltage input terminal of the primary feedback switching power supply chip U1 is connected to the feedback voltage terminal.
7. The light source and main board driving circuit of the projector according to claim 1, wherein the isolation transmission element is a photo coupler IC1, and a zener diode ZD1 is connected between an output positive electrode of the photo coupler IC1 and the ground GND 1.
8. The light source and main board driving circuit of the projector according to claim 1, wherein the rectifying circuit comprises a rectifying bridge DB1, an input end of the rectifying bridge DB1 is connected with a live wire ACL and a zero line CAN of the commercial power, an output end of the rectifying bridge DB is a positive pole dc+ of the direct current power and a reference ground GND1, a varistor MOV1 is connected between the live wire ACL and the zero line CAN, the live wire ACL is connected with a fuse F1 in series, the zero line CAN is connected with a thermistor NTC1 in series, and a polar capacitor C4 is connected between the positive pole dc+ and the reference ground GND 1.
9. The light source and main board driving circuit of the projector according to claim 1, wherein a filter circuit C5R12 composed of a parallel connection of a polar capacitor C5 and a resistor R12 is connected between the output ends of the light source driving circuit.
10. The light source and main board driving circuit of the projector according to claim 1, wherein a filter circuit C1R1 composed of a parallel connection of a polar capacitor C1 and a resistor R1 is connected between output ends of the main board driving circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202423057418.4U CN223261682U (en) | 2024-12-11 | 2024-12-11 | Light source and main board driving circuit of projector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202423057418.4U CN223261682U (en) | 2024-12-11 | 2024-12-11 | Light source and main board driving circuit of projector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN223261682U true CN223261682U (en) | 2025-08-22 |
Family
ID=96756703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202423057418.4U Active CN223261682U (en) | 2024-12-11 | 2024-12-11 | Light source and main board driving circuit of projector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN223261682U (en) |
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2024
- 2024-12-11 CN CN202423057418.4U patent/CN223261682U/en active Active
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