CN115664435A - Transmitter switch start-stop power amplifier circuit - Google Patents
Transmitter switch start-stop power amplifier circuit Download PDFInfo
- Publication number
- CN115664435A CN115664435A CN202210601487.3A CN202210601487A CN115664435A CN 115664435 A CN115664435 A CN 115664435A CN 202210601487 A CN202210601487 A CN 202210601487A CN 115664435 A CN115664435 A CN 115664435A
- Authority
- CN
- China
- Prior art keywords
- pin
- sensor chip
- level sensor
- signal
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Transmitters (AREA)
Abstract
The invention relates to a power amplifier circuit for starting and stopping a transmitter switch, which comprises a level sensor chip, wherein a pin 1 of the level sensor chip is used as a signal input end and is connected with an audio signal through a capacitor C2, a pin 2 is connected with a pin 3 through an adjustable resistor VR2, the pin 3, the pin 4 and the pin 5 are grounded, and a pin 6 is used as a signal output end and is connected with a pin 2 of a board card J1 on one hand and sequentially connected with a light-emitting diode D6, a light-emitting diode D5 and a resistor R3 on the other hand, the other end of the resistor R3 is connected with a pin 6 of the board card J1, the pin 3 of the board card J1 is respectively connected with the capacitor C2 and the signal input end of a switch high-voltage circuit, the pin 4 is connected with the high-low-voltage inverting input end of the switch high-voltage circuit, and the pin 5 is connected with the signal output end of the switch high-voltage circuit. The device adopts a digital design, simplifies the circuit structure, reduces or eliminates manual adjustment links, eliminates damage hidden dangers, improves the applicability, and improves the circuit sensitivity, response speed and working stability.
Description
Technical Field
This patent application belongs to communication equipment technical field, and more specifically says, relates to a transmitter switch opens and stops power amplifier circuit.
Background
The Guangzhou coast radio station (Guangzhou communication center) is the coast radio station with the largest scale and the most complete functions in the south China, participates in the international maritime life safety convention (SOLAS) on behalf of the country, fulfills the responsibility and the obligation specified by the International Maritime Organization (IMO), bears the ship safety communication duty of the whole south China sea area, and mainly bears three communication services of emergency safety duty, safety information broadcasting and ship public radio communication. Guangzhou coast stations use JRC transmitters 42, 13 of ten kilowatt transmitters and 29 of five kilowatt transmitters. The partial transmitters cover all transmission service types of the center, wherein the DSC service types, the NAVTEX service types, the SSB service types, the meteorological faxing service types and the like are broadcasted irregularly or intermittently, and no idle signals exist in the non-broadcast period. The signal sent to the signal sending station by the central control system at present has no independent control signal for switching on and off the high voltage and starting and stopping the power amplifier, and the high voltage of the signal sending machine needs to be kept in an on state for a long time, so that the normal transmission of the signal sending machine can be ensured when a service signal is sent. Therefore, the aging and depreciation of the hardware of the equipment are accelerated, and the possibility of manual misoperation is increased.
Regarding the KEY & PTT signal for controlling the transmitter to start and stop the power amplifier, the current scheme is to generate the KEY & PTT signal by Audio (AF) signal conversion in the way of "amplification-rectification-voltage division sampling-analog switch" and to access the corresponding interface of the transmitter for use. This circuit design has certain shortcomings: the method is mainly designed in a simulation mode, manual adjustment is needed, and parameter adjustment indexes are not clear enough; the circuit sensitivity and the response speed are general; individual capacitors in the circuit burn out after long-term use.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a transmitter switch start-stop power amplifier circuit, which does not need manual adjustment, loads a power amplifier high voltage and controls the output power of the whole machine when a service signal is sent, and closes the power amplifier high voltage when no service signal exists, so that the total power consumption of the transmitter operation can be effectively reduced, the operation cost is saved, the transmitter operation noise is reduced, the component depreciation loss is reduced, and the risk of manual misoperation or omission is reduced.
In order to solve the problems, the technical scheme adopted by the invention is as follows:
a power amplifier circuit for starting and stopping a transmitter switch is electrically connected with an audio signal and comprises a level sensor chip, wherein a pin 1 of the level sensor chip is used as a signal input end and is connected with the audio signal through a capacitor C2, a pin 2 of the level sensor chip is connected with a pin 3 of the level sensor chip through an adjustable resistor VR2, the pin 3 of the level sensor chip is grounded through a capacitor C4, a pin 4 of the level sensor chip is grounded, a pin 5 of the level sensor chip is grounded through a capacitor C6, and a pin 6 of the level sensor chip is used as a signal output end;
on one hand, the 6 pins of the level sensor chip are connected with the 2 pins of the board card J1, on the other hand, the 6 pins of the level sensor chip are sequentially connected with the light emitting diode D6, the light emitting diode D5 and the resistor R3, the other end of the resistor R3 is connected with the 6 pins of the board card J1, the 1 pin of the board card J1 is grounded, the 3 pins of the board card J1 are respectively connected with the capacitor C2 and the signal input end of the switch high-voltage circuit, the 4 pins of the board card are connected with the high-low voltage inverted input end of the switch high-voltage circuit, and the 5 pins of the board card are connected with the signal output end of the switch high-voltage circuit;
and 3 pins of the board J1 output audio signals.
The technical scheme of the invention is further improved as follows: the level sensor chip is model number NJM2072.
The technical scheme of the invention is further improved as follows: the led D5 is a yellow led.
The technical scheme of the invention is further improved as follows: the capacitor C6 is a polar capacitor.
The technical scheme of the invention is further improved as follows: the nominal value of the adjustable resistor VR2 is 100K omega.
Due to the adoption of the technical scheme, the invention has the beneficial effects that:
the invention upgrades the existing KEY & PTT signal conversion circuit, can utilize the existing switch high-voltage circuit, and can also integrate a new high-voltage switch control circuit, utilize the Audio Frequency (AF) signal conversion to generate the signal for controlling the high voltage of the switch of the transmitter and the power amplification of starting and stopping, control the high voltage of the starting and stopping of the transmitter and transmit the signal, promote and optimize the conversion performance of the KEY & PTT signal, and avoid the long-time starting condition of PA PWR (power amplification) and KEY & PTT (Push to Hold, push to talk). The high voltage of the power amplifier is loaded when a service signal is sent, the output power of the whole machine is controlled, and the high voltage of the power amplifier is closed by the transmitter when no service signal exists, so that the total power consumption of the transmitter in operation can be effectively reduced, the operation cost can be saved, the operation noise of the transmitter can be reduced, the depreciation loss of components can be reduced, and the risk of manual misoperation or omission can be reduced.
The circuit disclosed by the invention is designed autonomously by adopting a mode of combining a modularized chip and discrete components on a hardware level, upgrades and changes the KEY & PTT conversion circuit, adopts a digital mode to design, further simplifies the circuit structure, reduces or removes manual adjustment links, eliminates the hidden danger of damage of an original designed capacitor, enhances the applicability, and improves the sensitivity, response speed and working stability of the circuit. And manufacturing a PA ON signal control module, integrating the PA ON signal control module into a KEY & PTT and PA ON comprehensive signal control module, additionally installing the PA ON signal control module into the transmitter, outputting a control signal to a corresponding port or an access point of the transmitter, and controlling the high voltage of a switch and the power amplification of start and stop of the transmitter in real time according to a service audio signal.
Drawings
Fig. 1 is a circuit diagram of a control board of a transmitter according to the present invention;
FIG. 2 is a schematic diagram of the control circuit of the present invention;
fig. 3 is a signal waveform diagram of the present invention.
Detailed Description
The present invention will be described in further detail with reference to examples.
The invention discloses a transmitter switch start-stop power amplifier circuit, and the specific circuit layout refers to fig. 1-3, fig. 1 is a circuit layout drawing for making convenience for manufacturing a PCB, and fig. 2 is a schematic diagram for realizing functions.
With audio signal electric connection, including the level sensor chip, audio signal is connected through electric capacity C2 as signal input part to 1 foot of level sensor chip, and 2 feet of level sensor chip pass through adjustable resistance VR2 and connect 3 feet of level sensor chip, and electric capacity C4 ground connection is passed through to 3 feet of level sensor chip, and 4 feet of level sensor chip ground connection, 5 feet of level sensor chip pass through electric capacity C6 ground connection, and 6 feet of level sensor chip are as signal output part.
On one hand, the 6 pins of the level sensor chip are connected with the 2 pins of the board card J1, on the other hand, the 6 pins of the level sensor chip are sequentially connected with the light emitting diode D6, the light emitting diode D5 and the resistor R3, the other end of the resistor R3 is connected with the 6 pins of the board card J1, the 1 pin of the board card J1 is grounded, the 3 pins of the board card J1 are respectively connected with the capacitor C2 and the signal input end of the switch high-voltage circuit, the 4 pins of the board card are connected with the high-low voltage inverted input end of the switch high-voltage circuit, and the 5 pins of the board card are connected with the signal output end of the switch high-voltage circuit;
the 3 pins of the board card J1 output Audio (AF) signals.
Preferably, the level sensor chip is model No. NJM2072, the led D5 is a yellow led, the capacitor C6 is a polar capacitor (22 μ F), and the nominal value of the adjustable resistor VR2 is 100K Ω. The capacitor C4 is 104pF, the capacitor C2 is 10 muF, the types of the light emitting diode D6 and the light emitting diode D5 are IN4148, and the resistor R3 is 1K omega.
The transmitter switch start-stop power amplifier circuit can be used by combining the transmitter switch high-voltage circuit in the figure, and the transmitter switch high-voltage circuit is shown in the figure and is not described any more.
The working principle of the circuit is as follows:
aiming at the KEY & PTT start-stop power amplification function, an Audio (AF) signal enters through a pin 1 and is output through a pin 6 of a signal level sensor chip U2 (NJM 2072, a voice control circuit), when an audio service signal enters, the pin 6 is pulled to a low level from a high level, and is output to a pin 5 of a transmitter TB2, and the power emission of the transmitter is controlled.
For the PA ON switch high voltage function, audio (AF) signals enter via pin 1, pin 6 and pin 7 of the signal level sensor chip U1 (NJM 2072). U1's 6 feet are for opening high-voltage pulse foot, and 6 feet are from high level setting low level when Audio Frequency (AF) signal gets into 1 foot (the low level is effective) that can reset dual trigger monostable multivibrator chip U5 chip (74 HC 123), reset mouthful setting high level prerequisite at 3 feet, from 13 feet output a forward pulse, drive photocoupler U6 work, and output 5V voltage short pulse and give the corresponding pin of exciter PA ON ON-off switch, realize the automatic high voltage that opens. High pressure is turned off for 7 feet of U1A pulse pin, when the Audio (AF) signal is cut off, a short time delay is followed by setting a 7 pin from a high level to a low level, and a differential circuit (the formula of the differential circuit is as follows) built by using C7 and R8
) When R8 and C7 are far smaller than T/2 (T is a square wave period), a falling edge sharp-bottom wave is output, the level is pulled down instantly, the falling edge sharp-bottom wave is sent to a pin 2 (the pin 2 is a trigger pin, and the low level is effective) of a 555 timer chip U3, the time delay duration can be changed by adjusting the sizes of the peripheral variable resistor VR3 and the capacitor C8, and the falling edge sharp-bottom wave is sent to a pin 9 of U5 through the pin 3. At this time, the high-voltage state is achieved, a low level can be obtained from a pin 9 of a transmitter terminal interface board TB3, the low level is connected to a circuit through a pin 4 of a board card J1 interface, the 3 pin of the U5A is firstly sent, the low level is set to be in a low level reset state, the low level is converted into a high level through an inverter U4 (74 AHC1G 04) and then sent to a pin 11 of the U5B to enable the U5B to work, meanwhile, a low level is obtained after the delay of a 555 timer chip (the delay time tw =1.1 × vr3 × c8 in the circuit), a forward pulse is similarly output from a port 5 to drive a photocoupler U7 to work, and a 5V voltage short pulse is output to a corresponding pin of an actuator PA ON switch key, so that the high voltage is automatically turned off.
In consideration of KEY & PTT signals for controlling the transmitter to start, stop and power amplification, the current scheme is to use an Audio (AF) signal conversion mode to generate KEY & PTT signals, and the KEY & PTT signals are accessed to a corresponding interface of the transmitter for use. This circuit design has certain shortcomings: the method is mainly designed in a simulation mode, manual adjustment is needed, and parameter adjustment indexes are not clear enough; the sensitivity, stability and response speed of the circuit are general; individual capacitors in the circuit burn out after long-term use. Therefore, the part of the circuit is upgraded and realized in a digital mode. The response speed of the digital module is faster, the rising edge and the falling edge are more vertical and steep, and the response time can reach the ms and us levels; the differential circuit realizes accurate and timely triggering; the timer chip module can also calculate and design the required delay time more accurately; the photoelectric coupler greatly improves the electrical isolation through two conversions of the electric light and the photoelectric signal, effectively inhibits the electrical interference, and greatly improves the response speed and the comprehensive anti-interference capability.
In order to visually judge the fault and facilitate debugging, the light-emitting diodes with different colors are connected into the main circuit path, so that the in-use state monitoring and the subsequent operation and maintenance guarantee work are facilitated.
In the circuit, in order to adapt to different service type characteristics, a switch is specially arranged for starting or closing a high-voltage start-stop function, and for services such as ARQ (Automatic Repeat-reQuest) or FEC (Forward Error Correction) and the like, idle signals are continuously input, and the high voltage does not need to be frequently started or closed. And for DSC (digital selective calling), NAVTEX (navigation warning telex), SSB (synchronous signal) and weather facsimile and other services, the services are broadcast at irregular time or intermittently, no idle signal exists in the non-broadcast period, and in order to reduce the misoperation rate of manually switching on and off the high voltage, a high-voltage start-stop circuit can be introduced to timely and accurately process the requirements of the services.
Circuit waveform monitoring
According to KEY&PTT and PA ON control circuit characteristics, when audio signal input, the wave form is as TP1 shows, this wave form does not reflect the audio signal at the beginning and the diminishing trend change of the amplitude of the end sound stage, does not influence the circuit analysis. For KEY&The PTT starts and stops the power amplifier function, the Audio Frequency (AF) signal inputs 1 foot of U2, the output is TP9 (XMT) waveform, the Audio Frequency (AF) signal begins the stage and realizes the high level and sets the low level to change, control the sender to start the power amplifier output power; and in the tail sound stage of an Audio (AF) signal, low-level setting and high-level conversion are realized, and a transmitter is controlled to stop the power amplifier output power. For the switching high voltage function, an Audio (AF) signal is input to pin 1 of U1, a waveform such as TP2 is output from pin 6 of U1, and a high level sets a low level. At this time
The pin is connected with the 5V and the pull-up resistor and is in a high level state, namely, the 3 pin high level of the U5A and the 11 pin low level of the U5B are set, the U5A is in a working state, and the U5B is in a low level reset state. Therefore, after the 6-pin signal of U1 is inputted into the 1-pin of U5A, a short pulse signal with the shape of TP6 is outputted from the 13-pin, the action of the photocoupler U6 is controlled, and then a 5V short pulse voltage signal is generatedAnd the number is input to a corresponding pin of a PA ON button of an exciter switch panel to realize the function of starting high voltage. After an Audio (AF) signal is input into U1, a pulse signal with a shape like TP3 is output from a pin 7 at the same time, the conversion from low level to high level is realized, in the tail stage of the Audio (AF) signal, the level is set from high level to low level, a short-time low-level pulse is generated after the low-level pulse is optimized by a differential circuit and is input into a 555 timer U3 module, and a time-delay long-pulse signal like TP5 is output from a pin 7 of U3. At this time, a state where the high voltage is turned on,
the pin is set to be at a low level from the end of the exciter, and the pin 3 of the U5A is set to be at a low level and the pin 11 of the U5B is set to be at a high level after the input circuit, so that the U5A is in a low-level reset state and the U5B is in a working state. In the end sound stage of the delay long pulse signal, the conversion from high level setting to low level is realized, the conversion is input to the pin 9 of the U5B, a short pulse signal such as TP7 is output from the pin 5, the action of the photoelectric coupler U7 is controlled, a 5V short pulse voltage signal is further generated and input to the corresponding pin of the PA ON button of the exciter switch panel, and the function of closing the high voltage is realized. The TP8 waveform is a comprehensive body of TP6 and TP7 waveforms, and vividly shows the characteristics of a short voltage pulse occurrence time node and a waveform form of the switch high voltage. The digital module has the characteristics of high integration level, perfect functions, accurate parameters, sensitive and rapid response of waveform parameters, less temperature drift, stable work and the like, and can effectively meet and improve the requirement of transmitting an Audio (AF) signal of a transmitter. KEY&The PTT and PA ON control circuit signal waveforms are shown in fig. 3.
Wiring method
The circuit start-stop power amplifier part needs to conveniently access an Audio (AF) signal and a lead-out Key (XMT) signal and get electricity and go to the ground at a proper position; the high-voltage part of the switch needs to send electric pulses for opening high voltage and closing high voltage which are optically coupled into corresponding pins of an PA ON high-voltage switch of an exciter, high-low voltage level state values before and after the high voltage are sent into a board card, and the board card is matched with a phase inverter to control the part A or B of a U5 chip to work (U5A works before the high voltage, U5B is in a low level reset state to control the opening of the high voltage at any time, and U5A works after the high voltage is in a low level reset state, U5B works to control the closing of the high voltage at any time). Meanwhile, the 19 pin of the TB3 needs to be connected to the 20 pin, so that the 9 pin can normally feed back the change state of the working level. The design circuit is small and exquisite and easy to install, and can judge obstacles in time and be convenient to replace when a fault occurs. The terminal interface unit is installed in the lower rear terminal interface unit of the machine and fixed on the inner wall of the unit box in an overhead mode through insulating columns so as to meet basic conditions of circuit operation.
The design circuit is provided with six wiring terminals which are respectively a power supply (5 VDC), a Ground (GND), an audio signal input (AF), a KEY keying output signal (XMT SW), a PA ON switch high-voltage electric pulse output signal (PA PWR SW) and a switch high-voltage state level input signal (PA ON) and are respectively connected to corresponding wiring ports of terminal interface units TB2, TB3, J411 and an exciter PA ON switch button. Specific wiring information is shown in table 1. The terminal interface unit patch port definitions are shown in table 2. The exciter switch panel wiring port is defined in table 3.
Table 1KEY and PTT and PA ON control circuit wiring table
TABLE 2 terminal interface Unit terminal port table
TABLE 3 exciter switch panel terminal port table
3.5 Circuit efficiency measurement
According to the condition of a power amplification level main power amplifier of a transmitter corresponding to the project, the 10kW transmitter main power amplification level comprises 20 power amplifier modules, and the 5kW transmitter main power amplification level comprises 10 power amplifier modules; according to the static current value 4A/power amplifier module of the transmitter of 7 series models (JRS-714, JRS-753) of the brand, the high voltage 80VDC of the power amplifier circuit, the static current value 2A/power amplifier module of the transmitter of 9 series models (JRS-914, JRS-953) of the power amplifier circuit and the high voltage 110VDC of the power amplifier circuit, and according to the standby time of 12 hours when each transmitter works every day, the energy-saving calculation value is shown in a table 3. According to the estimation of long-term energy-saving benefit, the annual electric quantity of a 5kW JRS953 type transmitter exceeds 1 kilo-watt (kW.h), and the annual electric quantity of a 10kW JRS914 type transmitter exceeds 2 kilo-watt (kWh.h).
The estimated design project operation energy-saving efficiency is obvious.
Energy-saving measuring and calculating table for table 4KEY & PTT and PA ON control circuit
The JRC communicator is mainly used after the Guangzhou coast radio station is integrally transformed. The partial sender covers all the transmission service types of the center, wherein, the partial service types have the characteristic of broadcasting in an indefinite or intermittent way, and no idle signal exists in the non-broadcasting period. The signal sent to the sending station by the current central control system does not have independent switch high voltage and control signals for starting and stopping the power amplifier, and the high voltage of the sender needs to be kept in an open state for a long time, so that the normal emission of the sender can be ensured when a service signal is sent. The JRC short-wave transmitter adopts a digital mode to upgrade the existing PTT & KEY signal conversion circuit, integrates and adds a high-voltage switch control circuit, effectively achieves the purposes of reducing energy consumption, noise and hardware breakage and artificial misoperation risk, improves the integral operation quality of the transmitter and improves the signal transmission guarantee capability.
Claims (5)
1. The utility model provides a transmitter switch opens stops power amplifier circuit which characterized in that: the audio signal processing circuit is electrically connected with an audio signal and comprises a level sensor chip, wherein a pin 1 of the level sensor chip is used as a signal input end and is connected with the audio signal through a capacitor C2, a pin 2 of the level sensor chip is connected with a pin 3 of the level sensor chip through an adjustable resistor VR2, the pin 3 of the level sensor chip is grounded through a capacitor C4, a pin 4 of the level sensor chip is grounded, a pin 5 of the level sensor chip is grounded through a capacitor C6, and a pin 6 of the level sensor chip is used as a signal output end;
on one hand, a pin 6 of the level sensor chip is connected with a pin 2 of the board card J1, on the other hand, the pin 6 of the level sensor chip is sequentially connected with a light-emitting diode D6, a light-emitting diode D5 and a resistor R3, the other end of the resistor R3 is connected with the pin 6 of the board card J1, a pin 1 of the board card J1 is grounded, a pin 3 of the board card J1 is respectively connected with a capacitor C2 and a signal input end of the switch high-voltage circuit, a pin 4 of the board card is connected with a high-low voltage inverted input end of the switch high-voltage circuit, and a pin 5 of the board card is connected with a signal output end of the switch high-voltage circuit;
and 3 pins of the board J1 output audio signals.
2. The transmitter switch start-stop power amplifier circuit according to claim 1, characterized in that: the level sensor chip is model number NJM2072.
3. The transmitter switch start-stop power amplifier circuit according to claim 2, wherein: the led D5 is a yellow led.
4. The transmitter switch start-stop power amplifier circuit according to claim 3, characterized in that: the capacitor C6 is a polar capacitor.
5. The transmitter switch start-stop power amplifier circuit according to claim 4, wherein: the nominal value of the adjustable resistor VR2 is 100K omega.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210601487.3A CN115664435A (en) | 2022-05-30 | 2022-05-30 | Transmitter switch start-stop power amplifier circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210601487.3A CN115664435A (en) | 2022-05-30 | 2022-05-30 | Transmitter switch start-stop power amplifier circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115664435A true CN115664435A (en) | 2023-01-31 |
Family
ID=85024231
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210601487.3A Pending CN115664435A (en) | 2022-05-30 | 2022-05-30 | Transmitter switch start-stop power amplifier circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115664435A (en) |
-
2022
- 2022-05-30 CN CN202210601487.3A patent/CN115664435A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207354057U (en) | A kind of switch driving circuit, battery control circuit, battery and unmanned plane | |
| CN217307675U (en) | High-voltage circuit for transmitter switch | |
| GB2476466A (en) | Battery monitor for light. | |
| CN204650165U (en) | A kind of dual network beacon telemetering remote control terminal | |
| CN217183281U (en) | Transmitter switch start-stop power amplification circuit | |
| CN115664435A (en) | Transmitter switch start-stop power amplifier circuit | |
| CN101546171B (en) | Vehicle power supply time-delay device | |
| CN101701553A (en) | Full automatic controller of diesel generating set and control method | |
| CN105427554A (en) | Intelligent early warning broadcast control system with alarm indication function | |
| CN115001514B (en) | High-voltage circuit for switch of transmitter | |
| CN110987178A (en) | Laser signal detection device and system using solar cell | |
| CN2879538Y (en) | Electric power module for single board | |
| CN212083947U (en) | Power management system for robot | |
| CN208749981U (en) | A kind of commercial vehicle AMT controller | |
| CN106301114B (en) | Transportation throwing controller on unmanned vehicles | |
| CN211429315U (en) | Carrier-free alarm for medium wave broadcast transmitter | |
| CN215187474U (en) | Intelligent power distribution controller | |
| WO2024056021A1 (en) | System and method for controlling charging and discharging of battery pack, and garden tool system | |
| CN216509130U (en) | Novel lighting system of unmanned aerial vehicle | |
| CN221202576U (en) | Additional interference unit | |
| CN215813801U (en) | Electrical apparatus interface arrangement and electrical equipment | |
| CN221842368U (en) | Intelligent circuit breaker | |
| CN110748838A (en) | Integrated solar street lamp | |
| CN212875764U (en) | PBA three-mode switch control and protection circuit without software control | |
| CN210742687U (en) | Alarm clock capable of automatically gradually changing ring light |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |