CN102375300A - Power supply circuit for double-optical-filter switching device - Google Patents

Abstract

The invention provides a power supply circuit for a double-optical-filter switching device, which comprises an identification module, a power supply mode module, a switching module and a power supply module, wherein the identification module is used for respectively generating a first identification signal or a second identification signal according to the situation that the brightness of external light is lower or higher than the set brightness, and the power supply module is used for generating corresponding power supply voltages according to different power supply modes of the double-optical-filter switching device; and the switching module comprises two connecting nodes connected to the double-optical-filter switching device and is used for loading the power supply voltage to the corresponding connecting node according to the first identification signal and the second identification signal, and the power supply module is connected with an external direct current power supply and generates a working voltage capable of keeping the normal work of the identification module, the power supply mode module and the switching module. The power supply circuit provided by the invention can generate corresponding power supply voltages according to different power supply types, and can be compatible with the double-optical-filter switching devices with different power supply modes.

Description

Dual filter switcher power supply circuit

technical field

The invention relates to a power supply circuit of a double optical filter switcher.

Background technique

In order to keep the color of the camera’s image from being distorted during the day and have clear night vision at night, a double filter switcher (Infrared Cut Removable, ICR) is usually installed in front of the charge coupled device (CCD) of the camera. During the day, the ICR switches to an infrared filter, which filters all infrared light to obtain an undistorted color picture. At night, the ICR switches to an interference filter in the visible light region to eliminate other interfering stray light, so that the CCD can get a clear image. Currently, there are roughly three types of power supply modes for ICRs on the market: continuous power supply, pulse power supply, and instantaneous power supply. In the prior art, when using ICRs with different power supply modes, it is generally necessary to use a power supply circuit specially matching the power supply mode. Therefore, the existing ICR power supply circuit does not have the ability to be compatible with ICRs of different power supply modes.

Contents of the invention

In view of this, it is necessary to provide a dual filter switcher power supply circuit compatible with dual filter switchers in different power supply modes.

The invention provides a power supply circuit for a double optical filter switcher, which includes an identification module, a power supply mode module, a switching module and a power supply module. The identification module respectively generates a first identification signal or a second identification signal according to whether the brightness of the external light is lower or higher than a set brightness. The power supply mode module generates corresponding power supply voltages according to different power supply modes of the double filter switcher. The switch module includes two connection nodes for connecting to a dual filter switcher, and is used for loading the power supply voltage to a corresponding connection node according to the first identification signal and the second identification signal. The power supply module is connected with an external DC power supply and generates a working voltage for maintaining the normal operation of the identification module, the power supply mode module and the switching module.

Compared with the prior art, the power supply circuit of the dual filter switcher of the present invention can generate corresponding supply voltages according to different power supply types, and load the supply voltage to the corresponding connection nodes to drive the dual filter switcher to work , so that the power supply circuit of the dual optical filter switcher of the present invention is compatible with dual optical filter switchers of different power supply modes.

Description of drawings

FIG. 1 is a schematic circuit diagram of a power supply circuit of a dual filter switcher according to a preferred embodiment of the present invention.

Explanation of main component symbols

Double filter switcher power supply circuit 10

Power module 102

Identification module 104

Power Mode Module 106

Switch Module 108

External DC power supply V _DC-input

Working voltage _VCC

Conversion module U1

Input terminal VI

output terminal VO

Feedback terminal VG

Photoresistor CDS

Resistors R1, R3, R4, R5, R6, R7, R8,

R9, R10, R11, R12, R13, R14

Switches S1, S2, S3

Capacitor C1, C2

Transistor Q7, Q8, Q9

MOS tubes Q1, Q2, Q3, Q4, Q5, Q6

The first connection node G1

The second connection node G2

Port P _out

Mode port P1, P2, P3

Detailed ways

Please refer to FIG. 1 , a power supply circuit 10 for a dual filter switcher according to a preferred embodiment of the present invention includes a power supply module 102 , an identification module 104 , a power supply mode module 106 and a switching module 108 .

The power module 102 is used to connect an external DC power supply V _DC-input and generate a working voltage V _CC for maintaining the normal operation of the identification module 104 , the power supply mode module 106 and the switching module 108 . Specifically, the power module 102 includes a DC voltage to DC voltage conversion module U1, two resistors R10, R11 and two capacitors C1, C2. In this embodiment, the conversion module U1 is a low dropout regulator (Lowdropout regulator, LDO), which includes an input terminal VI, an output terminal VO and a feedback terminal VG. An external DC power supply V _DC-input is connected to the input terminal VI. After conversion by the conversion module U1, the output terminal VO outputs a working voltage V _CC . The resistors R10 and R11 are connected in series between the output terminal VO and the ground, and the feedback terminal VG is connected between the resistors R10 and R11 to collect the voltage output from the output terminal VO. The conversion module U1 adjusts the output voltage of the output terminal VO through the feedback voltage collected by the feedback terminal VG, so as to keep the working voltage V _CC stable. The input terminal VI and the output terminal VO are also grounded through the capacitors C1 and C2 respectively to filter the AC power that may be input or output to the conversion module U1.

The identification module 104 is configured to generate a first identification signal or a second identification signal according to whether the brightness of the external light is lower or higher than a set brightness. Specifically, the identification module 104 includes a photosensitive resistor CDS, three resistors R6, R7, R9 and an NPN transistor Q9. Preferably, resistor R7 is an adjustable resistor. The photosensitive resistor CDS and the resistor R7 are connected in series between the working voltage V _CC and the ground. The base of the transistor Q9 is connected between the photoresistor CDS and the resistor R7 through the resistor R9, the emitter of the transistor Q9 is grounded, and the collector of the transistor Q9 is connected to the working voltage V _CC through the resistor R6. The collector of the transistor Q9 is the output terminal of the identification module 104 . The resistance value of the photoresistor CDS increases when the external light becomes dark, causing the base voltage of the triode Q9 to also increase. The opposite is true when the external light becomes brighter. In this way, by setting the resistance value of the resistor R7, the base voltage of the transistor Q9 can reach the threshold for turning on or off the transistor Q9 when the external light changes to the desired setting brightness. Wherein, the set brightness can be set according to the brightness of the environment at the boundary between day and night (such as the ambient brightness at 6 o'clock in the evening or 6 o'clock in the morning). When the external light is darker than the set brightness, the triode Q9 is turned on, and its collector generates a first identification signal, that is, a low level. When the external light is brighter than the set brightness, the triode Q9 is cut off, and its collector generates a second identification signal, that is, a high level.

The power supply mode module 106 is used for generating corresponding power supply voltages according to different power supply modes of the dual filter switcher (Infrared Cut Removable, ICR). Specifically, the power supply mode module 106 includes a central processing unit (CPU), an N-channel MOS transistor Q2, a P-channel MOS transistor Q1, four resistors R1, R12, R13, R14 and three switches S1, S2, S3. The CPU includes a port P _out and three mode ports P1, P2, P3. The CPU can output a continuous high level, a pulse signal or an instantaneous high level through the port P _out according to the level status of the mode ports P1, P2, and P3. The mode ports P1, P2, P3 are respectively connected to the working voltage V _CC through the resistors R12, R13, R14, and are also connected to the ground through the switches S1, S2, S3 respectively. The port P _out is connected to the gate of the MOS transistor Q2, the source of the MOS transistor Q2 is grounded, and the drain of the MOS transistor Q2 is connected to the working voltage V _CC through the resistor R1. The gate of the MOS transistor Q1 is connected to the drain of the MOS transistor Q2 , the drain of the MOS transistor Q1 is connected to the working voltage V _CC , and the voltage output by the source of the MOS transistor Q1 is the supply voltage generated by the power supply mode module 106 .

When the power supply mode of the ICR is continuous power supply, switch S1 is turned on, switches S2 and S3 are turned on, so that the mode port P1 is at low level, and the mode ports P2 and P3 are at high level. At this time, the CPU controls the port P _out to continuously output a high level. In this way, the MOS transistor Q2 is turned on, and the MOS transistor Q1 is also turned on, and the source output voltage of the MOS transistor Q1 is approximately equal to the working voltage V _CC , which is a continuous high level.

When the power supply mode of the ICR is pulse power supply, turn on the switch S2, open the switches S1, S3, so that the mode port P2 is low level, and the mode ports P1, P3 are high level. At this time, the CPU controls the port P _out to output a pulse signal (such as a pulse width modulation signal). With the change of the high and low levels in the pulse signal, the MOS transistor Q2 and the MOS transistor Q1 are also turned on or off, so that the MOS transistor Q1 The source output voltage is also a pulse signal.

When the power supply mode of the ICR is instantaneous power supply, turn on the switch S3, open the switches S1 and S2, so that the mode port P3 is at low level, and the mode ports P1 and P2 are at high level. At this time, the CPU controls the port P _out to output an instantaneous high level. In this way, the source output voltage of the MOS transistor Q1 is also an instantaneous high level.

Setting mode ports P1, P2, P3 and the resistors R12, R13, R14 connected to them and three switches S1, S2, S3 are used to select different voltage modes for the CPU output to adapt to the ICR of different power supply modes. However, it can be understood that in the mass production process, when the ICR is determined, its power supply mode is determined, and at this time, the CPU can only output the voltage type corresponding to the ICR. Alternatively, when the subsequently selected ICRs have different power supply types, it is only necessary to make the CPU output a voltage type corresponding to the ICR without changing the hardware structure of the circuit. In this way, the mode ports P1 , P2 , P3 and the paired resistors R12 , R13 , R14 , and the three switches S1 , S2 , S3 do not need to be set.

Since the source of the MOS transistor Q2 is grounded, the port P _out only needs to output a high level greater than zero to turn on the MOS transistor Q2. In this way, the power supply mode module 106 has lower requirements on the output voltage of the port P _out . Therefore, it can be understood that when the high-level voltage output by the port P _out is relatively high and can directly turn on the MOS transistor Q1 , the resistor R1 and the MOS transistor Q2 do not need to be set.

The switching module 108 includes two first connection nodes G1 and a second connection node G2 for connecting to an ICR, and the switching module 108 is used to switch the power supply generated by the power supply mode module 106 to A voltage is applied to a corresponding connection node. Specifically, the switching module 108 includes four resistors R3, R4, R5 and R8, two NPN transistors Q7, Q8, two N-channel MOS transistors Q4, Q5 and two P-channel MOS transistors Q3, Q6. The base of the transistor Q8 is connected to the collector of the transistor Q9 through the resistor R8, the emitter of the transistor Q8 is grounded, and the collector of the transistor Q8 is connected to the working voltage V _CC through the resistor R4. The base of the transistor Q7 is connected to the collector of the transistor Q8 through the resistor R5, the emitter of the transistor Q7 is grounded, and the collector of the transistor Q7 is connected to the working voltage V _CC through the resistor R3. The gates of MOS transistors Q3 and Q5 are connected to the collector of transistor Q8, the source of MOS transistor Q5 is grounded, the drain of MOS transistor Q5 is connected to the source of MOS transistor Q3, and the drain of MOS transistor Q3 is connected to the MOS transistor Source of Q1. The gates of MOS transistors Q4 and Q6 are connected to the collector of transistor Q7, the source of MOS transistor Q6 is grounded, the drain of MOS transistor Q6 is connected to the source of MOS transistor Q4, and the drain of MOS transistor Q4 is connected to the MOS transistor Source of Q1. Here, the node between the MOS transistors Q3 and Q5 is defined as the first connection node G1, and the node between the MOS transistors Q4 and Q6 is defined as the second connection node G2. The first connection node G1 and the second connection node G2 are used to connect an ICR.

When the external light is darker than the set brightness, the collector of the transistor Q9 generates a first identification signal, that is, a low level, and the transistor Q8 is cut off, and its collector voltage is approximately equal to the working voltage V _CC , that is, a high level. At this time, the transistor Q7 is turned on, and its collector voltage is approximately equal to the ground voltage, that is, a low level. In this way, the MOS transistors Q3 and Q6 are turned off, the MOS transistors Q4 and Q5 are turned on, and the power supply voltage generated by the electrical mode module 106 is applied to the second connection node G2, so that the ICR realizes forward rotation (or reverse rotation). When the external light is brighter than the set brightness, the collector of the triode Q9 generates a second identification signal, that is, a high level, and the triode Q8 is turned on, and its collector voltage is approximately equal to the ground voltage, that is, a low level. At this time, the transistor Q7 is cut off, and its collector voltage is approximately equal to the working voltage V _CC , that is, a high level. In this way, the MOS transistors Q3 and Q6 are turned on, and the MOS transistors Q4 and Q5 are turned off, and the power supply voltage generated by the electrical mode module 106 is applied to the first connection node G1, so that the ICR achieves inversion (or forward rotation).

The transistor and the MOS transistor in this embodiment function as a switch. However, it can be understood that where a triode is used, a MOS tube or other switching elements can also be used, and where a MOS tube is used, a triode or other switching elements can also be used. At the same time, the photosensitive resistor CDS is used to change the resistance value according to the brightness of the external light, thereby playing a role in identifying the brightness of the external light. However, it can be understood that the present invention is not limited to using only the photosensitive resistor CDS, and other photoelectric sensors can also be used. such as photodiodes.

The power supply circuit 10 of the dual filter switcher of the present invention can output the corresponding supply voltage according to different power supply types, and load the supply voltage to the corresponding connection node to drive the ICR to work, so that the dual filter switch of the present invention can The device power supply circuit 10 is compatible with ICRs of different power supply modes.

Those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Alterations and variations are within the scope of the claimed invention.

Claims (10)

1. two optical filter switch feed circuit, it comprises:

An identification module is used for being below or above a setting brightness and producing one first identification signal or one second identification signal respectively according to the brightness of extraneous light;

A powering mode module is used for producing corresponding supply voltage according to two optical filter switch various power patterns;

A handover module comprises two connected nodes that are used to be connected to two optical filter switchs, is used for according to this first identification signal and second identification signal, and this supply voltage is loaded on a corresponding connected node;

A power module is used to connect an external dc power, and produces a WV of keeping this identification module, this powering mode module and this handover module operate as normal.

2. as claimed in claim 1 pair of optical filter switch feed circuit is characterized in that, this power module comprises the modular converter of a DC voltage to DC voltage, two resistance and two electric capacity; This modular converter comprises that one is connected to the input end of this external dc power, an output terminal and a feedback end that is used to export this WV; These two resistance are connected between this output terminal and the ground; This feedback end is connected between these two resistance, and this input end and this output terminal are respectively through these two capacity earths.

3. as claimed in claim 2 pair of optical filter switch feed circuit is characterized in that this modular converter is a low pressure difference linear voltage regulator.

4. as claimed in claim 1 pair of optical filter switch feed circuit; It is characterized in that; This identification module comprises an electro-optical pickoff, first triode of a NPN type and first, second, third resistance, and this electro-optical pickoff and this first resistance are connected between this WV and the ground; The base stage of this first triode is connected between this electro-optical pickoff and this first resistance through this second resistance; The emitter grounding of this first triode, the collector of this first triode is connected to this WV through the 3rd resistance, collector this first identification signal of output or one second identification signal of this first triode.

5. as claimed in claim 4 pair of optical filter switch feed circuit is characterized in that, this electro-optical pickoff is for changing the photoresistance of resistance according to extraneous light.

6. as claimed in claim 4 pair of optical filter switch feed circuit is characterized in that this first resistance is adjustable resistance.

7. as claimed in claim 4 pair of optical filter switch feed circuit; It is characterized in that; This handover module comprises the 4th, the 5th, the 6th, the 7th resistance, second, third triode of NPN type, the 3rd, the 4th metal-oxide-semiconductor of first, second metal-oxide-semiconductor of N raceway groove and P raceway groove; The base stage of this second triode is connected to the collector of this first triode through this first resistance, the emitter grounding of this second triode, and the collector of this second triode connects WV through this second resistance to this; The base stage of the 3rd triode is connected to the collector of this second triode through the 3rd resistance, the emitter grounding of the 3rd triode, and the collector of the 3rd triode connects this WV through the 4th resistance; The grid of this second, third metal-oxide-semiconductor all is connected to the collector of this second triode, the source ground of this second metal-oxide-semiconductor, and the drain electrode of this second metal-oxide-semiconductor is connected to the source electrode of the 3rd metal-oxide-semiconductor, and the drain electrode of the 3rd metal-oxide-semiconductor is connected to this supply voltage; The grid of this first, the 4th metal-oxide-semiconductor all is connected to the collector of the 3rd triode, the source ground of the 4th metal-oxide-semiconductor, and the drain electrode of the 4th metal-oxide-semiconductor is connected to the source electrode of this first metal-oxide-semiconductor, and the drain electrode of the 4th metal-oxide-semiconductor is connected to this supply voltage; Node between this second, third metal-oxide-semiconductor is this first node, and the node between this first, the 4th metal-oxide-semiconductor is this Section Point.

8. as claimed in claim 1 pair of optical filter switch feed circuit; It is characterized in that this powering mode module comprises a central processing unit and one the 5th metal-oxide-semiconductor, this central processing unit comprises a port; This port is by the voltage of this its output of central processing unit control; This port is connected to the grid of the 5th metal-oxide-semiconductor, and the drain electrode of the 5th metal-oxide-semiconductor is connected to this WV, and the source electrode of the 6th metal-oxide-semiconductor is output as this supply voltage.

9. as claimed in claim 8 pair of optical filter switch feed circuit; It is characterized in that the 5th metal-oxide-semiconductor is the N raceway groove, this powering mode module also comprises the 6th metal-oxide-semiconductor and one the 8th resistance of a P raceway groove; This port is connected to the grid of the 6th metal-oxide-semiconductor; The source ground of the 6th metal-oxide-semiconductor, the drain electrode of the 6th metal-oxide-semiconductor is connected to this WV through the 8th resistance, and the grid of the 5th metal-oxide-semiconductor is connected to the drain electrode of the 6th metal-oxide-semiconductor.

10. as claimed in claim 8 pair of optical filter switch feed circuit is characterized in that, this powering mode module also comprises three pull-up resistors and three switches, and this central processing unit also comprises three mode port; These three mode port are connected to this WV through these three pull-up resistors respectively, simultaneously also respectively through these three switch ground connection; When making a mode port be in low level state when all the other two switch opens of a switch connection, this port output of this central processing unit control continues high level, pulse signal or instantaneous high level.

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