Current-to-voltage type smoke monitoring circuit

Abstract

The utility model provides a current-to-voltage type smoke monitoring circuit, which comprises a transmitting tube driving module, a current-to-voltage conversion module, a voltage amplification module, a control type power supply module, an infrared transmitting tube T1, an infrared receiving tube T2, a main controller and a main power supply module, the output end of the main power supply module supplies power to the infrared transmitting tube T1, the infrared receiving tube T2 is installed beside the infrared transmitting tube T1, and the air in the environment can pass through a gap between the infrared transmitting tube T1 and the infrared receiving tube T2. The voltage output end of the main controller is connected to the voltage input end of the control type power supply module, and the voltage output end of the control type power supply module supplies power to the infrared receiving tube T2. According to the current-to-voltage type smoke monitoring circuit, whether the infrared transmitting tube is electrified or not is controlled, so that the infrared transmitting tube is controlled to emit light for detection as required, and energy waste caused by random light emission of the infrared transmitting tube is avoided.

Description

Technical Field

[0001] The utility model relates to a monitoring circuit, in particular to a current-to-voltage type smoke monitoring circuit. Background Art

[0002] Smoke alarms play a vital role in fire prevention and damage control. With the increasing use of fire sources and electricity in homes, the incidence of home fires has also increased. When a fire occurs, if it is not handled properly or the alarm system is slow to respond, it often leads to serious casualties. This situation occurs largely because people lack awareness of fire prevention and fail to implement necessary preventive measures in a timely manner. Smoke alarms are an important tool for fire prevention. They can quickly sense the smoke in the early stages of a fire and sound the alarm.

[0003] The existing smoke alarm circuit adopts a photoelectric control detection module, which determines the smoke concentration by the smoke entering between the light receiving unit and the light emitting unit, and converts it into an electrical signal for transmission. Although it can also detect smoke, the photoelectric control detection module adopts an integrated smoke monitoring chip. Since the integrated smoke monitoring chip is a relatively special and high-value chip, the integrated smoke monitoring chip is expensive, which increases the production cost of the entire smoke alarm circuit and reduces the market competitiveness. Utility Model Content

[0004] The utility model provides a current-to-voltage type smoke monitoring circuit, which solves the problem that the detection part in the prior art is too complicated and can save the cost of circuit components.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: the utility model provides a current-to-voltage type smoke monitoring circuit, including: a transmitting tube driving module, a current-to-voltage conversion module, a voltage amplification module, a controlled power supply module, an infrared transmitting tube T1, an infrared receiving tube T2, a main controller and a total power supply module; the output end of the total power supply module supplies power to the infrared transmitting tube T1, the transmitting tube driving module is connected to the total power supply module and the circuit where the infrared transmitting tube T1 is located, the transmitting tube driving module is used to control whether the infrared transmitting tube T1 is connected to the first output end of the total power supply module, and the control end of the transmitting tube driving module is connected to the first output end of the main controller; the infrared transmitting tube T1 is connected to the infrared transmitting tube T1. An infrared receiving tube T2 is installed, and the gap between the infrared transmitting tube T1 and the infrared receiving tube T2 allows the ambient air to pass through; the voltage output end of the main controller is connected to the voltage input end of the controlled power supply module, and the voltage output end of the controlled power supply module supplies power to the infrared receiving tube T2; the two ends of the infrared receiving tube T2 are respectively connected to the two input ends of the current-voltage conversion module, and the current-voltage conversion module is used to convert the current passing through the infrared receiving tube T2 into a voltage output; the output end of the current-voltage conversion module is connected to the input end of the voltage amplification module, and the voltage output end of the controlled power supply module provides a reference voltage for the voltage amplification module, and the output end of the voltage amplification module is connected to the input end of the main controller.

[0006] Preferably, the transmitting tube driving module includes: a capacitor C4, a resistor R8 and a controllable switch, the cathode of the infrared transmitting tube T1 is grounded through the controllable switch, the anode of the infrared transmitting tube T1 is connected to the anode of the capacitor C4, the connection point between the anode of the capacitor C4 and the anode of the infrared transmitting tube T1 is connected to the resistor R8, the negative electrode of the capacitor C4 is grounded, the other end of the resistor R8 is connected to the output end of the total power supply module, and the control end of the controllable switch is the control end of the transmitting tube driving module.

[0007] Preferably, the current-to-voltage conversion module includes: an inter-group amplifier A1, a resistor R2, a resistor R6 and a capacitor C1, the anode of the capacitor C1 is connected to the inverting input terminal S1 of the inter-group amplifier A1, the cathode of the capacitor C1 is connected to the output terminal O1 of the inter-group amplifier A1, one end of the resistor R6 is connected to the positive electrode of the capacitor C6, the other end of the resistor R6 is connected to the negative electrode of the capacitor C6, the first end of the resistor R2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the second end of the resistor R2 is connected to the voltage output end of the controlled power supply module; the anode of the infrared receiving tube T2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the cathode of the infrared receiving tube T2 is connected to the inverting input terminal S1 of the inter-group amplifier A1.

[0008] Preferably, the standard power supply module includes: a resistor R1, a resistor R5 and a capacitor C2, the second end of the resistor R2 is connected to one end of the resistor R1, the second end of the resistor R2 is connected to the positive electrode of the capacitor C2, the negative electrode of the capacitor C2 and the other end of the resistor R1 are grounded, the connection point between the resistor R1 and the positive electrode of the capacitor C5 is connected to one end of the resistor R5, and the other end of the resistor R5 is the voltage input terminal SDA\VFEN of the controlled power supply module.

[0009] Preferably, the voltage amplification module includes: a resistor R4, a resistor R7, a capacitor C3 and a voltage amplifier U1, the output end of the cross-group amplifier A1 is connected to the first end of the resistor R3 and the in-phase input end P2 of the voltage amplifier U1, the second end of the resistor R3 is connected to the connection point between the resistor R5 and the capacitor R2, the second end of the resistor R3 is also connected to the first end of the resistor R4, the second end of the resistor R4 is connected to the inverting input end S2 of the voltage amplifier U1, the second end of the resistor R4 and the connection point between the voltage amplifier U1 are connected to the negative electrode of the capacitor C3, the positive electrode of the capacitor C3 is connected to the output end a2 of the voltage amplifier U1, the positive electrode of the capacitor C3 is connected to one end of the resistor R7, the cathode of the capacitor C3 is connected to the other end of the resistor R7, and the output end a2 of the cross-group amplifier A1 is the output end of the voltage amplification module.

[0010] Preferably, the controllable switch includes: resistor R9, resistor R10, resistor R11, switch transistor Q1 and switch transistor Q2, the emitter of switch transistor Q1 is connected to one end of resistor R10, the other end of resistor R10 is grounded through resistor R9, the base of switch transistor Q1 is connected to the emitter of switch transistor Q2, the base of switch transistor Q2 is connected to one end of resistor R11, the other end of resistor R11 is the control end SCL\IR of the controllable switch, the collector of switch transistor Q1 is connected to the collector of switch transistor Q2, and the wiring point between the collector of switch transistor Q1 and the collector of switch transistor Q2 is connected to the cathode of infrared emitting tube T1.

[0011] Preferably, the output terminal of the cross-group amplifier A1 is connected to the non-inverting input terminal of the voltage amplifier U1.

[0012] Compared with the prior art, the utility model has the following beneficial effects: the current-to-voltage smoke monitoring circuit adopts an infrared transmitting module and an infrared receiving module to monitor smoke, and the infrared transmitting tube is powered by the output end of the main power supply module. The transmitting tube driving module is used to control whether the infrared transmitting tube is connected to the current, thereby controlling whether the infrared transmitting tube is powered on, so as to control the infrared transmitting tube to emit light when necessary, and avoid the infrared transmitting tube emitting light at will and causing energy waste; the controlled power supply module supplies power to the infrared receiver, and the infrared receiver will show a change in resistance due to the intensity of the received light, thereby showing a change in the current passing through the infrared receiver, and this small change in current is difficult to be recognized by the main controller, so a current-to-voltage conversion module is adopted to realize the transmission of the received current by the infrared receiver to the current-to-voltage conversion module, and the cross-group amplifier is used to convert the current into a recognizable electrical signal voltage, and the electrical signal is amplified by the voltage amplifier U1, and then transmitted to the main controller for signal recognition, which can make the smoke monitoring signal more accurate, and the circuit is clear and easy to use, reducing the operating cost. Finally, the controlled power supply module supplies power under the control of the main controller, which not only provides operating voltage for the infrared receiving tube, but also provides a reference voltage for the subsequent voltage amplification module, so that both the infrared receiving tube and the voltage amplification module work under control, and the voltage provided by the infrared receiving tube is correlated with the reference voltage of the voltage amplification module, which can be used for reference to each other during subsequent identification.

[0013] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the circuit diagram of the current-to-voltage smoke monitoring circuit. DETAILED DESCRIPTION

[0015] In order to make the technical means, creative features, objectives and functions of the present invention clearer and easier to understand, the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods:

[0016] like Figure 1As shown, the utility model proposes a current-to-voltage smoke monitoring circuit, comprising: a transmitting tube driving module, a current-to-voltage conversion module, a voltage amplification module, a controlled power supply module, an infrared transmitting tube T1, an infrared receiving tube T2, a main controller and a main power supply module; the output end +3V0 of the main power supply module supplies power to the infrared transmitting tube T1, the transmitting tube driving module is connected to the main power supply module and the circuit where the infrared transmitting tube T1 is located, the transmitting tube driving module is used to control whether the infrared transmitting tube T1 is connected to the first output end of the main power supply module, and the control end of the transmitting tube driving module is connected to the first output end of the main controller; when the transmitting tube driving module is connected to the output end of the main power supply module to supply power to the infrared transmitting tube T1, the infrared transmitting tube sends a monitoring signal to the infrared receiver to monitor the smoke. An infrared receiving tube T2 is installed next to the infrared transmitting tube T1, and the gap between the infrared transmitting tube T1 and the infrared receiving tube T2 allows the ambient air to pass through; the voltage output end of the main controller is connected to the voltage input end of the controlled power supply module, and the voltage output end of the controlled power supply module supplies power to the infrared receiving tube T2; after the infrared receiving tube T2 is powered on, when it receives the monitoring signal sent by the infrared transmitting tube, it monitors the ambient air in the gap between them;

[0017] The two ends of the infrared receiving tube T2 are respectively connected to the two input ends of the current-voltage conversion module, which is used to convert the current passing through the infrared receiving tube T2 into a voltage output; and transmit the output voltage to the voltage amplifier U1 for amplification processing.

[0018] The output end of the current-voltage conversion module is connected to the input end of the voltage amplifier module. The voltage output end of the controlled power supply module provides a reference voltage for the voltage amplifier module. The output end of the voltage amplifier module is connected to the input end of the main controller. The voltage amplifier module transmits the amplified monitoring signal to the main controller for identification.

[0019] The transmitting tube driving module includes: capacitor C4, resistor R8 and a controllable switch. The cathode of the infrared transmitting tube T1 is grounded through the controllable switch. The anode of the infrared transmitting tube T1 is connected to the anode of the capacitor C4. The connection point between the anode of the capacitor C4 and the anode of the infrared transmitting tube T1 is connected to the resistor R8. The negative electrode of the capacitor C4 is grounded. The other end of the resistor R8 is connected to the output end of the main power supply module. The control end of the controllable switch is the control end of the transmitting tube driving module. The transmitting tube driving module controls the main power supply module to supply power to the infrared transmitting tube T1.

[0020] The current-voltage conversion module includes: an inter-group amplifier A1, a resistor R2, a resistor R6 and a capacitor C1, wherein the anode of the capacitor C1 is connected to the inverting input terminal S1 of the inter-group amplifier A1, the cathode of the capacitor C1 is connected to the output terminal O1 of the inter-group amplifier A1, one end of the resistor R6 is connected to the positive electrode of the capacitor C6, and the other end of the resistor R6 is connected to the negative electrode of the capacitor C6, the first end of the resistor R2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the second end of the resistor R2 is connected to the voltage output terminal of the controlled power supply module; the anode of the infrared receiving tube T2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the cathode of the infrared receiving tube T2 is connected to the inverting input terminal S1 of the inter-group amplifier A1. The anode of the infrared receiving tube T2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the cathode of the infrared receiving tube T2 is connected to the inverting input terminal S1 of the inter-group amplifier A1.

[0021] The controlled power supply module includes: resistor R1, resistor R5 and capacitor C2, the second end of resistor R2 is connected to one end of resistor R1, the second end of resistor R2 is connected to the positive electrode of capacitor C2, the negative electrode of capacitor C2 and the other end of resistor R1 are grounded, the connection point between resistor R1 and the positive electrode of capacitor C5 is connected to one end of resistor R5, and the other end of resistor R5 is the voltage input terminal SDA\VFEN of the controlled power supply module. The controlled power supply module supplies power to its infrared receiving tube. Resistors R1 and R5 are used for voltage division, and the voltage output from the voltage output terminal of the main controller is divided and output.

[0022] The voltage amplification module includes: a resistor R4, a resistor R7, a capacitor C3 and a voltage amplifier U1, the output end of the cross-group amplifier A1 is connected to the first end of the resistor R3 and the in-phase input end P2 of the voltage amplifier U1, the second end of the resistor R3 is connected to the connection point between the resistor R5 and the capacitor R2, the second end of the resistor R3 is also connected to the first end of the resistor R4, the second end of the resistor R4 is connected to the inverting input end S2 of the voltage amplifier U1, the second end of the resistor R4 and the connection point of the voltage amplifier U1 are connected to the negative electrode of the capacitor C3, the positive electrode of the capacitor C3 is connected to the output end a2 of the voltage amplifier U1, the positive electrode of the capacitor C3 is connected to one end of the resistor R7, the cathode of the capacitor C3 is connected to the other end of the resistor R7, and the output end a2 of the cross-group amplifier A1 is the output end of the voltage amplification module. The voltage amplification module performs electrical signal amplification processing on the voltage output by the cross-group amplifier.

[0023] The controllable switch includes: resistor R9, resistor R10, resistor R11, switch transistor Q1 and switch transistor Q2, the emitter of switch transistor Q1 is connected to one end of resistor R10, the other end of resistor R10 is grounded through resistor R9, the base of switch transistor Q1 is connected to the emitter of switch transistor Q2, the base of switch transistor Q2 is connected to one end of resistor R11, the other end of resistor R11 is the control end SCL\IR of the controllable switch, the collector of switch transistor Q1 is connected to the collector of switch transistor Q2, and the connection point of the collector of switch transistor Q1 and the collector of switch transistor Q2 is connected to the cathode of infrared emitting tube T1. It is realized that the cathode of infrared emitting tube T1 is turned on under the control of the main controller.

[0024] The output terminal of the cross-group amplifier A1 is connected to the non-inverting input terminal of the voltage amplifier U1.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. Current-to-voltage smoke monitoring circuit, characterized in that: include: Transmitter tube drive module, current-voltage conversion module, voltage amplification module, controlled power supply module, infrared transmitting tube T1, infrared receiving tube T2, main controller and total power supply module; The output end of the main power supply module supplies power to the infrared emitting tube T1, the emitting tube driving module is connected to the circuit where the main power supply module and the infrared emitting tube T1 are located, the emitting tube driving module is used to control whether the infrared emitting tube T1 is connected to the first output end of the main power supply module, and the control end of the emitting tube driving module is connected to the first output end of the main controller; An infrared receiving tube T2 is installed next to the infrared transmitting tube T1, and the gap between the infrared transmitting tube T1 and the infrared receiving tube T2 allows ambient air to pass through; The voltage output terminal of the main controller is connected to the voltage input terminal of the controlled power supply module, and the voltage output terminal of the controlled power supply module supplies power to the infrared receiving tube T2; The two ends of the infrared receiving tube T2 are respectively connected to the two input ends of the current-voltage conversion module, and the current-voltage conversion module is used to convert the current passing through the infrared receiving tube T2 into a voltage output; The output end of the current-voltage conversion module is connected to the input end of the voltage amplifier module. The voltage output end of the controlled power supply module provides a reference voltage for the voltage amplifier module. The output end of the voltage amplifier module is connected to the input end of the main controller.

2. The current-to-voltage smoke monitoring circuit according to claim 1, characterized in that: The transmitting tube driving module includes: a capacitor C4, a resistor R8 and a controllable switch. The cathode of the infrared transmitting tube T1 is grounded through the controllable switch, the anode of the infrared transmitting tube T1 is connected to the anode of the capacitor C4, the connection point between the anode of the capacitor C4 and the anode of the infrared transmitting tube T1 is connected to the resistor R8, the negative electrode of the capacitor C4 is grounded, the other end of the resistor R8 is connected to the output end of the total power supply module, and the control end of the controllable switch is the control end of the transmitting tube driving module.

3. The current-to-voltage smoke monitoring circuit according to claim 2, characterized in that: The current-to-voltage conversion module includes: an inter-group amplifier A1, a resistor R2, a resistor R6 and a capacitor C1, wherein the anode of the capacitor C1 is connected to the inverting input terminal S1 of the inter-group amplifier A1, the cathode of the capacitor C1 is connected to the output terminal O1 of the inter-group amplifier A1, one end of the resistor R6 is connected to the positive electrode of the capacitor C6, the other end of the resistor R6 is connected to the negative electrode of the capacitor C6, the first end of the resistor R2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the second end of the resistor R2 is connected to the voltage output terminal of the controlled power supply module; the anode of the infrared receiving tube T2 is connected to the non-inverting input terminal P1 of the inter-group amplifier A1, and the cathode of the infrared receiving tube T2 is connected to the inverting input terminal S1 of the inter-group amplifier A1.

4. The current-to-voltage smoke monitoring circuit according to claim 3, characterized in that: The controlled power supply module includes: a resistor R1, a resistor R5 and a capacitor C2, the second end of the resistor R2 is connected to one end of the resistor R1, the second end of the resistor R2 is connected to the positive electrode of the capacitor C2, the negative electrode of the capacitor C2 and the other end of the resistor R1 are grounded, the connection point between the resistor R1 and the positive electrode of the capacitor C5 is connected to one end of the resistor R5, and the other end of the resistor R5 is the voltage input terminal SDA\VFEN of the controlled power supply module.

5. The current-to-voltage smoke monitoring circuit according to claim 4, characterized in that: The voltage amplification module includes: a resistor R4, a resistor R7, a capacitor C3 and a voltage amplifier U1. The output end of the cross-group amplifier A1 is connected to the first end of the resistor R3 and the in-phase input end P2 of the voltage amplifier U1. The second end of the resistor R3 is connected to the connection point between the resistor R5 and the capacitor R2. The second end of the resistor R3 is also connected to the first end of the resistor R4. The second end of the resistor R4 is connected to the inverting input end S2 of the voltage amplifier U1. The connection point between the second end of the resistor R4 and the voltage amplifier U1 is connected to the negative electrode of the capacitor C3. The positive electrode of the capacitor C3 is connected to the output end a2 of the voltage amplifier U1. The positive electrode of the capacitor C3 is connected to one end of the resistor R7. The cathode of the capacitor C3 is connected to the other end of the resistor R7. The output end a2 of the cross-group amplifier A1 is the output end of the voltage amplification module.

6. The current-to-voltage smoke monitoring circuit according to claim 1, characterized in that: The controllable switch includes: resistor R9, resistor R10, resistor R11, switch transistor Q1 and switch transistor Q2, the emitter of switch transistor Q1 is connected to one end of resistor R10, the other end of resistor R10 is grounded through resistor R9, the base of switch transistor Q1 is connected to the emitter of switch transistor Q2, the base of switch transistor Q2 is connected to one end of resistor R11, the other end of resistor R11 is the control end SCL\IR of the controllable switch, the collector of switch transistor Q1 is connected to the collector of switch transistor Q2, and the wiring point between the collector of switch transistor Q1 and the collector of switch transistor Q2 is connected to the cathode of infrared emitting tube T1.

7. The current-to-voltage smoke monitoring circuit according to claim 2, characterized in that: The output terminal of the cross-group amplifier A1 is connected to the non-inverting input terminal of the voltage amplifier U1.

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