Double-color warning lamp driving circuit of ultrasonic liquid level sensor

Abstract

The utility model discloses a double-color warning lamp driving circuit of an ultrasonic liquid level sensor. The double-color warning lamp driving circuit comprises an isolation power supply, a signal acquisition and blind area judgment circuit, a blind area state locking circuit and a driving circuit, the isolated power supply comprises a chip U4 and a transformer T, a pin 1, a pin 2 and a pin 3 of the chip U4 are all grounded, and a pin 5 of the chip U4 is electrically connected with one end of a capacitor C4 and one end of a capacitor C5. According to the utility model, through cooperation of the signal acquisition and blind area determination circuit and the blind area state locking circuit, the state of the drive circuit can be accurately controlled, normal opening and closing of the warning lamp LED1 and the warning lamp LED2 are ensured, the situation of abnormal indication of the warning lamp LED1 and the warning lamp LED2 caused by false triggering of blind area signals is avoided, the stability in the use process is improved, and the use safety of the warning lamp LED1 and the warning lamp LED2 is ensured. And in cooperation with independent power supply of an isolation power supply, external electromagnetic interference can be reduced, and the stability in the using process is further improved.

Description

Technical Field

[0001] This utility model relates to the field of ultrasonic liquid level sensor technology, and in particular to a dual-color warning light driving circuit for an ultrasonic liquid level sensor. Background Technology

[0002] The dual-color warning light drive circuit of the ultrasonic liquid level sensor is used to realize the audible and visual alarm function when the water level is too high or too low. Through the audible and visual alarm, it can effectively remind users to deal with abnormal water level situations in time and ensure the safe and stable operation of the system. The dual-color warning light drive circuit in the prior art does not have the function of blind zone shielding and locking, and there is a possibility of false triggering in the blind zone. The ultrasonic liquid level gauge cannot effectively detect the liquid level in the blind zone and may output full scale or random signals, which may trigger the red LED to be constantly lit (false alarm of liquid level too high) or the green LED to be off (false alarm of abnormality), thus providing incorrect information to the staff. Therefore, this application proposes a dual-color warning light drive circuit for the ultrasonic liquid level sensor. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a dual-color warning light driving circuit for an ultrasonic liquid level sensor.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A dual-color warning light driving circuit for an ultrasonic liquid level sensor includes an isolation power supply, a signal acquisition and blind zone judgment circuit, a blind zone state locking circuit, and a driving circuit.

[0006] The isolation power supply includes chip U4 and transformer T. Pins 1, 2, and 3 of chip U4 are all grounded. Pin 5 of chip U4 is electrically connected to one end of capacitor C4 and one end of capacitor C5. The other end of capacitor C4 is electrically connected to one end of resistor R11. The other end of capacitor C5 is electrically connected to one end of resistor R12. The other ends of resistors R11 and R12 are both grounded. Pin 6 of chip U4 is electrically connected to one end of resistor R15. Pin 7 of chip U4 is electrically connected to the anode of diode D2 and the cathode of diode D1. The cathode of diode D2 is electrically connected to the base of transistor Q3. The other end of resistor R15 is electrically connected to the emitter of transistor Q3. Pin 8 of chip U4 is electrically connected to one end of resistor R14. The other end of resistor R14 is electrically connected to capacitor C. One end of 6, the positive terminal of diode D1 is electrically connected to one end of capacitor C6. Pin 9 of chip U4 is electrically connected to one end of resistor R13. The other end of resistor R13 and the other end of capacitor C6 are both electrically connected to pin 1 of transformer T. Pin 1 of transformer T is electrically connected to the positive terminal of diode D3. The negative terminal of diode D3 is electrically connected to the negative terminal of diode D4. The positive terminal of diode D4 is electrically connected to pin 2 of transformer T. Pin 2 of transformer T is electrically connected to the collector of transistor Q3. Pins 4 and 3 of transformer T are electrically connected to the positive terminals of diode D6 and diode D5, respectively. The negative terminal of diode D6 is electrically connected to one end of resistor R16. The negative terminal of diode D5 is electrically connected to one end of capacitor C7. The other end of capacitor C7 is electrically connected to the other end of resistor R16.

[0007] Preferably, the signal acquisition and blind zone judgment circuit includes a filter circuit, a comparator U1, and a resistor R8. The filter circuit includes resistors R1 and R2, capacitors C1 and C2. One end of resistor R1 is electrically connected to one end of capacitor C1, and one end of resistor R2 is electrically connected to one end of capacitor C2. Pins 1 and 2 of comparator U1 are electrically connected to the other ends of capacitors C1 and C2, respectively. Pin 3 of comparator U1 is electrically connected to one end of resistor R8.

[0008] Preferably, the blind zone state locking circuit includes a trigger U2, pin 2 of trigger U2 is electrically connected to pin 3 of comparator U1, pin 1 of trigger U2 is electrically connected to a high level VCC, pin 3 of trigger U2 is electrically connected to one end of resistor R9, pin 4 of trigger U2 is electrically connected to one end of resistor R10, the other end of resistor R10 is electrically connected to one end of capacitor C3, and the other end of capacitor C3 is electrically connected to one end of resistor R4.

[0009] Preferably, the driving circuit includes an inverter U3. Pin 1 of inverter U3 is electrically connected to the other end of resistor R4. Pin 1 of inverter U3 is electrically connected to one end of resistor R5. The other end of resistor R5 is electrically connected to pin 3 of inverter U3. Pin 2 of inverter U3 is electrically connected to one end of resistor R6. The other end of resistor R6 is grounded. The other end of resistor R9 is electrically connected to one end of resistor R3 and the base of transistor Q1. The other end of resistor R3 is electrically connected to one end of warning light LED1. The collector of Q1 is electrically connected to one end of the warning light LED1, and the other end of the warning light LED1 is electrically connected to the other end of the resistor R8. Pin 3 of the inverter U3 is electrically connected to one end of the resistor R7 and the base of the transistor Q2. The emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is electrically connected to the other end of the resistor R7. The collector of the transistor Q2 is electrically connected to one end of the warning light LED2. The other ends of both the warning light LED1 and the warning light LED2 are electrically connected to the other end of the resistor R8.

[0010] Preferably, the comparator U1 is an LM393, and pin 2 of the comparator U1 is used to set the blind zone determination threshold.

[0011] Preferably, pin 2 of the trigger U2 is the clock terminal CLK, and resistors R10, R9 and C3 constitute a reset circuit, which is used to reset the trigger U2 and unlock the state when the effective liquid level signal is restored.

[0012] Preferably, the warning light LED1 is red and the warning light LED2 is green.

[0013] Compared with existing technologies, the beneficial effects of this utility model are:

[0014] This invention, through the combination of signal acquisition and blind zone judgment circuits and blind zone state locking circuits, can accurately control the state of the drive circuit, ensuring the normal opening and closing of warning lights LED1 and LED2, avoiding abnormal indication of warning lights LED1 and LED2 due to false triggering of blind zone signals, improving stability during use, and further enhancing stability during use by using an isolated power supply to reduce external electromagnetic interference. Attached Figure Description

[0015] Figure 1 This is a block diagram of a dual-color warning light driving circuit for an ultrasonic liquid level sensor proposed in this utility model.

[0016] Figure 2 The circuit diagram of the isolated power supply for the dual-color warning light driving circuit of the ultrasonic liquid level sensor proposed in this utility model;

[0017] Figure 3 The circuit diagram shows the connection of the signal acquisition and blind zone judgment circuit, the blind zone state locking circuit, and the drive circuit of the dual-color warning light drive circuit of the ultrasonic liquid level sensor proposed in this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] Reference Figure 1-3 A dual-color warning light driving circuit for an ultrasonic liquid level sensor includes an isolation power supply, a signal acquisition and blind zone judgment circuit, a blind zone state locking circuit, and a driving circuit.

[0020] The isolation power supply includes chip U4 and transformer T. Pins 1, 2, and 3 of chip U4 are all grounded. Pin 5 of chip U4 is electrically connected to one end of capacitor C4 and one end of capacitor C5. The other end of capacitor C4 is electrically connected to one end of resistor R11. The other end of capacitor C5 is electrically connected to one end of resistor R12. The other ends of resistors R11 and R12 are both grounded. Pin 6 of chip U4 is electrically connected to one end of resistor R15. Pin 7 of chip U4 is electrically connected to the anode of diode D2 and the cathode of diode D1. The cathode of diode D2 is electrically connected to the base of transistor Q3. The other end of resistor R15 is electrically connected to the emitter of transistor Q3. Pin 8 of chip U4 is electrically connected to one end of resistor R14. The other end of resistor R14 is electrically connected to capacitor C6. One end of the circuit is connected to the positive terminal of diode D1 and one end of capacitor C6. Pin 9 of chip U4 is connected to one end of resistor R13. The other end of resistor R13 and the other end of capacitor C6 are both connected to pin 1 of transformer T. Pin 1 of transformer T is connected to the positive terminal of diode D3. The negative terminal of diode D3 is connected to the negative terminal of diode D4. The positive terminal of diode D4 is connected to pin 2 of transformer T. Pin 2 of transformer T is connected to the collector of transistor Q3. Pins 4 and 3 of transformer T are connected to the positive terminals of diode D6 and diode D5, respectively. The negative terminal of diode D6 is connected to one end of resistor R16. The negative terminal of diode D5 is connected to one end of capacitor C7. The other end of capacitor C7 is connected to the other end of resistor R16.

[0021] The signal acquisition and blind zone detection circuit includes a filter circuit, a comparator U1, and a resistor R8. The filter circuit includes resistors R1 and R2, capacitors C1 and C2. One end of resistor R1 is electrically connected to one end of capacitor C1, and one end of resistor R2 is electrically connected to one end of capacitor C2. Pins 1 and 2 of comparator U1 are electrically connected to the other ends of capacitors C1 and C2, respectively. Pin 3 of comparator U1 is electrically connected to one end of resistor R8. The comparator U1 is an LM393, and pin 2 of comparator U1 is used to set the blind zone detection threshold.

[0022] The blind zone state lockout circuit includes a trigger U2. Pin 2 of trigger U2 is electrically connected to pin 3 of comparator U1. Pin 1 of trigger U2 is electrically connected to a high level VCC. Pin 3 of trigger U2 is electrically connected to one end of resistor R9. Pin 4 of trigger U2 is electrically connected to one end of resistor R10. The other end of resistor R10 is electrically connected to one end of capacitor C3. The other end of capacitor C3 is electrically connected to one end of resistor R4. Pin 2 of trigger U2 is the clock input CLK. Resistors R10, R9, and C3 constitute a reset circuit, used to reset trigger U2 and release the lockout state when the effective liquid level signal is restored.

[0023] The driving circuit includes an inverter U3. Pin 1 of inverter U3 is electrically connected to the other end of resistor R4. Pin 1 of inverter U3 is electrically connected to one end of resistor R5. The other end of resistor R5 is electrically connected to pin 3 of inverter U3. Pin 2 of inverter U3 is electrically connected to one end of resistor R6. The other end of resistor R6 is grounded. The other end of resistor R9 is electrically connected to one end of resistor R3 and the base of transistor Q1. The other end of resistor R3 is electrically connected to one end of warning light LED1. The collector of transistor Q1 is electrically connected to one end of warning light LED1. The other end of warning light LED1 is electrically connected to the other end of resistor R8. Pin 3 of inverter U3 is electrically connected to one end of resistor R7 and the base of transistor Q2. The emitter of transistor Q2 is grounded. The collector of transistor Q2 is electrically connected to the other end of resistor R7. The collector of transistor Q2 is electrically connected to one end of warning light LED2. The other ends of warning lights LED1 and LED2 are both electrically connected to the other end of resistor R8. Warning light LED1 is red, and warning light LED2 is green. This invention, through the cooperation of signal acquisition, blind zone judgment circuit, and blind zone state locking circuit, can accurately control the state of the drive circuit, ensuring the normal opening and closing of warning lights LED1 and LED2, avoiding abnormal indication of warning lights LED1 and LED2 due to false triggering of blind zone signals, improving stability during use. In addition, with the separate power supply of isolation power supply, external electromagnetic interference can be reduced, further improving stability during use.

[0024] Working Principle: During use, electrical isolation is achieved between the input and output through isolation components such as transformer T, capacitors, and resistors, cutting off the direct current path and providing a safe power supply for the entire circuit. The output signal of the ultrasonic liquid level sensor, after being filtered by a filter circuit to remove high-frequency noise, enters the positive input terminal of comparator U1. The blind zone detection threshold is set through the negative input terminal of comparator U1. When the liquid level enters the blind zone, comparator U1 outputs a high-level trigger lock signal to the clock terminal CLK of trigger U3. Trigger U3 outputs a high-level signal to force the drive circuit to enter the preset state. When the effective liquid level signal is restored, the trigger... When trigger U2 is unlocked, its output is isolated by resistors R9 and R10 and capacitor C3. When the liquid level is high, transistor Q1 is turned on, and warning light LED1 illuminates. The resistor controls inverter U3 to turn off transistor Q2. When the liquid level returns to normal, transistor Q1 turns off, transistor Q2 turns on, and warning light ED2 illuminates to alert personnel. By locking the device promptly when entering the blind zone and restoring it when a liquid level signal is received, false triggering of blind zone signals can be effectively avoided, thus preventing abnormal indication of warning lights LED1 and LED2 and improving stability during use.

[0025] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A dual color warning light drive circuit for an ultrasonic liquid level sensor, comprising: The isolation power supply, the signal acquisition and blind area judgment circuit, the blind area state locking circuit and the driving circuit are included. The isolation power supply includes a chip U4 and a transformer T, the pin 1, the pin 2 and the pin 3 of the chip U4 are grounded, one end of the capacitor C4 and one end of the capacitor C5 are electrically connected to the pin 5 of the chip U4, one end of the resistor R11 and one end of the resistor R12 are electrically connected to the other end of the capacitor C5, the other end of the resistor R11 and the other end of the resistor R12 are grounded, one end of the resistor R15 is electrically connected to the pin 6 of the chip U4, the positive electrode of the diode D2 and the negative electrode of the diode D1 are electrically connected to the pin 7 of the chip U4, the negative electrode of the diode D2 is electrically connected to the base of the triode Q3, the other end of the resistor R15 and the emitter of the triode Q3 are electrically connected, one end of the resistor R14 is electrically connected to the pin 8 of the chip U4, one end of the capacitor C6 is electrically connected to the other end of the resistor R14, the positive electrode of the diode D1 is electrically connected to one end of the capacitor C6, one end of the resistor R13 is electrically connected to the pin 9 of the chip U4, the other end of the resistor R13 and the other end of the capacitor C6 are electrically connected to the pin 1 of the transformer T, the positive electrode of the diode D3 is electrically connected to the pin 1 of the transformer T, the negative electrode of the diode D3 is electrically connected to the negative electrode of the diode D4, the positive electrode of the diode D4 is electrically connected to the pin 2 of the transformer T, the pin 2 of the transformer T is electrically connected to the collector of the triode Q3, the positive electrode of the diode D6 and the positive electrode of the diode D5 are electrically connected to the pin 4 and the pin 3 of the transformer T respectively, one end of the resistor R16 is electrically connected to the negative electrode of the diode D6, one end of the capacitor C7 is electrically connected to the negative electrode of the diode D5, the other end of the capacitor C7 and the other end of the resistor R16 are electrically connected.

2. The dual color warning light driving circuit of an ultrasonic liquid level sensor according to claim 1, wherein, The signal acquisition and blind area judgment circuit includes a filter circuit, a comparator U1 and a resistor R8, the filter circuit includes a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2, one end of the resistor R1 and one end of the capacitor C1 are electrically connected, one end of the resistor R2 and one end of the capacitor C2 are electrically connected, the pin 1 and the pin 2 of the comparator U1 are electrically connected to the other end of the capacitor C1 and the other end of the capacitor C2 respectively, one end of the resistor R8 is electrically connected to the pin 3 of the comparator U1.

3. The dual color warning light driving circuit of an ultrasonic liquid level sensor according to claim 2, wherein, The blind area state locking circuit includes a flip-flop U2, the pin 2 of the flip-flop U2 is electrically connected to the pin 3 of the comparator U1, the pin 1 of the flip-flop U2 is electrically connected to a high level VCC, one end of the resistor R9 is electrically connected to the pin 3 of the flip-flop U2, one end of the resistor R10 is electrically connected to the pin 4 of the flip-flop U2, one end of the capacitor C3 is electrically connected to the other end of the resistor R10, one end of the resistor R4 is electrically connected to the other end of the capacitor C3.

4. The dual color warning light driving circuit of an ultrasonic liquid level sensor according to claim 3, wherein, The driving circuit comprises an inverter U3, a pin 1 of the inverter U3 is electrically connected with the other end of a resistor R4, one end of a resistor R5 is electrically connected with the pin 1 of the inverter U3, the other end of the resistor R5 is electrically connected with a pin 3 of the inverter U3, one end of a resistor R6 is electrically connected with a pin 2 of the inverter U3, the other end of the resistor R6 is grounded, the other end of the resistor R9 is electrically connected with one end of a resistor R3 and a base of a transistor Q1, the other end of the resistor R3 is electrically connected with one end of a warning light LED1, a collector of the transistor Q1 is electrically connected with one end of the warning light LED1, the other end of the warning light LED1 is electrically connected with the other end of a resistor R8, one end of a resistor R7 and a base of a transistor Q2 are electrically connected with the pin 3 of the inverter U3, an emitter of the transistor Q2 is grounded, a collector of the transistor Q2 is electrically connected with the other end of the resistor R7, one end of a warning light LED2 is electrically connected with the collector of the transistor Q2, the other end of the warning light LED1 and the other end of the warning light LED2 are electrically connected with the other end of the resistor R8.

5. The dual color warning light driver circuit for an ultrasonic liquid level sensor according to claim 2, wherein The comparator U1 is of a model of LM393, and a pin 2 of the comparator U1 is used for setting a blind area judgment threshold value.

6. The dual color warning light driver circuit for an ultrasonic liquid level sensor according to claim 3, wherein A pin 2 of the flip-flop U2 is a clock end CLK, a resistor R10, the resistor R9 and a capacitor C3 constitute a reset circuit, which is used for resetting the flip-flop U2 when an effective liquid level signal is recovered, and releasing a locked state.

7. The dual color warning light driver circuit for an ultrasonic liquid level sensor according to claim 4, wherein The warning light LED1 is a bright red light, and the warning light LED2 is a bright green light.

Images