Countdown timer

Abstract

The utility model discloses a countdown timer which comprises a digital display panel and a control circuit board, the digital display panel comprises a digital driving circuit and a digital segment code, and the digital driving circuit is driven by the control circuit board to be in communication connection with the digital segment code. And the digital driving circuit comprises an MOS (Metal Oxide Semiconductor) tube for controlling the color of the digital segment code and a first singlechip for controlling countdown display of the digital segment code. According to the countdown timer of the utility model, the single-chip microcomputer and the drive circuit can be integrated on the digital display panel of the countdown timer, and a part of functions of the control circuit board can be shared by utilizing the relatively abundant space of the digital display panel, so that the size of the control circuit board is smaller.

Description

TECHNICAL FIELD

[0001] The utility model relates to traffic signal control technical field especially, relates to a countdown timer. BACKGROUND

[0002] Countdown timer as a kind of cooperation signal lamp provides timing display equipment, can let vehicle driver accurately judge red green light remaining time in advance make good prediction, obtain application in traffic intersection.The size weight of ordinary countdown timer is relatively big, needs to occupy more space of bar when installing, requires that bar has strong bearing capacity.

[0003] It is very unfavorable in the area that there is often strong wind, especially in typhoon season, even the bar cannot bear heavy shaking and cause serious safety hazard.In order to solve this problem, one scheme in the prior art is to install a smaller countdown in the signal lamp to reduce the bar bearing problem, however, this scheme puts signal lamp and countdown in the same position, which violates the relevant standards;Another scheme is to make the countdown lighter and thinner, and this scheme makes the internal space of the equipment small, and puts forward many restrictions on the size and weight of each control component. UTILITY MODEL CONTENT

[0004] To solve the problems of large size and low integration of the existing countdown timer, the utility model provides a countdown timer.

[0005] The specific technical scheme is as follows:

[0006] A kind of countdown timer, including: digital display board and control circuit board, the digital display board includes digital drive circuit and the number field code of display countdown, the digital drive circuit is driven with the number field code communication connection by the control circuit board, digital drive circuit includes the MOS tube of control number field code color and the first single-chip microcomputer of control number field code countdown display.

[0007] Further, the digital drive circuit further includes a triode, and the triode and the MOS tube are in communication connection with the first single-chip microcomputer.

[0008] Further, the control circuit board includes a second single-chip microcomputer, a rectifier circuit, a signal detection circuit, a signal output interface, an RS485 interface, an address dial code, a voltage stabilizing circuit, a photosensitive sensor and a DC power module.

[0009] Further, the second single-chip microcomputer is in communication connection with the digital display board through the signal output interface, and the RS485 interface and the photosensitive sensor are respectively connected with the second single-chip microcomputer.

[0010] Further, the second single-chip microcomputer is connected with the signal detection circuit, the signal detection circuit comprises six light-electricity couplings, the rectifier circuit comprises six rectifier bridges, the six rectifier bridges are connected with the six light-electricity couplings one by one, and the rectifier circuit is connected with the DC power module.

[0011] Further, the voltage stabilizing circuit is connected with the output end of the DC power module.

[0012] Further, the RS485 interface is connected with a self-recovery fuse.

[0013] Further, the signal output interface comprises a power positive pole, a power negative pole and a serial communication line.

[0014] Further, the number field code comprises a red LED lamp, a green LED lamp and a yellow LED lamp.

[0015] Further, the number of the digital driving circuit and the number field code is two.

[0016] The above technical scheme has the following advantages or technical effects:

[0017] 1. The utility model provides a control circuit of higher integration, installs in lighter and thinner countdown timer shell, keeps digital display unit size unchanged simultaneously, provides a more suitable scheme for the safe use of countdown timer in the area that often scratches strong wind.

[0018] 2. The utility model integrates single-chip microcomputer and driving circuit on the digital display board of countdown timer, utilizes the relatively abundant space of digital display board to share part of the function of control circuit board, thereby making the size of control circuit board smaller.

[0019] 3. The single-chip microcomputer on the digital display board can communicate with the single-chip microcomputer of control circuit board by utilizing serial ports, makes the number of internal connecting lines of countdown timer reduce from 20 to 4, and is beneficial to the size reduction of the overall thickness of equipment. DRAWINGS

[0020] Figure 1 It is the principle diagram of the utility model;

[0021] Figure 2 It is the circuit connection schematic diagram of MOS tube and triode of the utility model. DETAILED DESCRIPTION

[0022] In order to make the technical scheme of the utility model more clear, the utility model is further explained in detail in combination with the drawings and specific embodiments.

[0023] As Figure 1As shown, a countdown timer comprises a digital display panel and a control circuit board, the digital display panel comprising a digital drive circuit and a number field code for displaying countdown, the digital drive circuit being driven by the control circuit board and being in communication with the number field code, the digital drive circuit comprising MOS tubes for controlling the color of the number field code, a first single-chip microcomputer for controlling the countdown display of the number field code, and a triode, the triode and the MOS tubes being in communication with the first single-chip microcomputer, the control circuit board comprising a second single-chip microcomputer, a rectifier circuit, a signal detection circuit, a signal output interface, an RS485 interface, an address dial code, a voltage stabilizing circuit, a photosensitive sensor, and a DC power module. The digital display panel and the control circuit board are arranged in a countdown housing.

[0024] The digital display panel is composed of 88 number field codes composed of red, green, and yellow LED lights and a digital drive circuit, the digital drive circuit being used for receiving control signals sent by the control circuit board via a serial port to drive the display of the number field codes and color commands, the digital drive circuit comprising a triode, MOS tubes, and a first single-chip microcomputer, the triode being used for negative driving of the number field code, the MOS tubes being used for color voltage control of the number field code, and the first single-chip microcomputer being used for receiving control signals via a serial port and controlling the on-off of the triode and the MOS tubes according to commands, thereby realizing countdown display.

[0025] The second single-chip microcomputer runs a main program of the control circuit board system, is used for detecting changes in input six-way voltage signals, and after completing countdown learning in a learning signal period, sends display commands to the digital display panel via a signal output interface; the second single-chip microcomputer receives data commands accessed via the RS485 interface, sends display commands to the digital display panel after analysis by the second single-chip microcomputer, so that the 88 number field codes display numbers. The signal output interface comprises positive and negative poles of a power supply and serial communication lines.

[0026] The photosensitive sensor is connected with the second single-chip microcomputer, and is used for detecting environmental brightness, informing the first single-chip microcomputer of the digital display panel to adopt a PWM waveform output mode to adjust the light-dark proportion of output signals, and the second single-chip microcomputer adjusts the brightness of the display of the 88 number field codes by detecting the environmental brightness.

[0027] The rectifier circuit comprises six rectifier bridges, the rectifier bridges comprising 220VAC signal input interfaces, and outputting fluctuating DC signals to the signal detection circuit and the DC power module after rectifying AC signals.

[0028] The second single-chip microcomputer is connected with the signal detection circuit, and the signal detection circuit comprises six optocouplers for voltage detection, and outputs 5VDC square wave pulses to the IO port of the second single-chip microcomputer, and the six rectifier bridges are connected with the six optocouplers one by one.

[0029] The RS485 interface outputs AB differential lines, and the RS485 interface is connected with a self-recovery fuse as high-voltage protection.

[0030] The output end of the voltage stabilizing circuit and the DC power module is connected to convert 24VDC into 5VDC for the system work of the control circuit board.

[0031] The model of the first single-chip microcomputer is STC8H1K08, the model of the triode is MMBT3904, the model of the MOS tube is NCE60P10K, the model of the second single-chip microcomputer is STC8H1K24, the model of the RS485 interface chip is MAX485E, the model of the self-recovery fuse is MD6, the model of the photoelectric coupler is EL817, the model of the voltage stabilizing power supply is LM7805, the model of the photosensitive sensor is 5528, and the model of the rectifier bridge is DB207S.

[0032] The second single-chip microcomputer STC8H1K24 of the control circuit board has two serial ports, one of which is connected with the RS485 (serial port 1) interface to receive the control command of the host computer, and the other of which is connected with the output interface (serial port 2) to connect the digital display board and output display data; the 6-way IO interface of the second single-chip microcomputer STC8H1K24 is connected with the square wave signal output by the photoelectric coupler EL817; the AD detection pin of the second single-chip microcomputer STC8H1K24 is connected with a photosensitive sensor 5528 to detect the ambient brightness and adjust the display brightness output. The 6-way 220V signal is converted into a fluctuating DC signal through the rectifier bridge DB207S, one side of which is transmitted to the input end of the photoelectric coupler EL817, and the other side is transmitted to the power module to convert 24VDC; one way of the 24VDC power module is connected with the digital display board through the output interface, and the other way is connected with the voltage stabilizing power supply LM7805 to output 5VDC to the chips of the control circuit board to work; the output interface has 24V positive, negative, 5V positive and data four-way signals, which are transmitted to the digital display board; the input line of the chip MAX485E of the RS485 interface is connected with the self-recovery fuse MD6 in series to prevent high-voltage interference.

[0033] The digital display board is divided into ten digits and unit digits, and includes two digital driving circuits and number field codes, and the circuit structures are the same. The number 8 of the digital display board is composed of seven pen segments of red, yellow and green color LEDs, the anodes of the red, yellow and green LEDs of each pen segment are all connected with the output of the corresponding red, yellow and green driving MOS tube NCE60P10K, and the cathodes of the red, yellow and green LEDs of each pen segment are all connected with the collector of the triode MMBT3904, so that the number 8 on each digital display board has 3 MOS tubes and 7 triodes, which are controlled by the IO of the single-chip microcomputer STC8H1K08 respectively. The source of the 3 MOS tubes NCE60P10K is connected with 24VDC for controlling the anode voltage on-off of the three color LEDs. The collector of the 7 triodes MMBT3904 is connected with the negative electrode of the LED pen segment for controlling the negative electrode voltage on-off of the seven segment codes. The single-chip microcomputer STC8H1K08 receives the data output by the control circuit board through the serial port, controls the on-off of the MOS tube and the triode after decoding, and realizes digital display.

[0034] As shown in Figure 2 , taking the MOS tube NCE60P10K and the triode MMBT3904 of a red LED lamp as an example, the circuit is shown as Figure 2 , the source of the MOS tube Q1 is connected with 24VDC, the gate and the drain of the MOS tube Q1 are connected with the resistor R1, the resistance value of the resistor R1 is 10kΩ, the gate of the MOS tube Q1 is connected with the collector of the triode Q4 through the resistor R4, the resistance value of the resistor R4 is 10kΩ, the emitter of the triode Q4 is grounded, and the base of the triode Q4 is connected with the red LED lamp through the resistor R7.

[0035] The utility model discloses a single-chip microcomputer and driving circuit are integrated on the digital display board of countdown timer, utilize the relatively abundant space of digital display board to share the part function of control circuit board, thereby make control circuit board size smaller, the single-chip microcomputer on digital display board can utilize the serial port and the single-chip microcomputer of control circuit board communication, make the number of internal connection lines of countdown timer reduce, further reduce the size of countdown timer.

[0036] The above-mentioned embodiments only express several implementation manners of the utility model, and the description is more specific and detailed, but it can not be understood as the limitation of the utility model patent range. It should be pointed out that for ordinary skilled person in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, which all belong to the protection range of the utility model. Therefore, the protection range of the utility model patent should be subject to the appended claims.

Claims

1. A countdown timer, characterized in that, The utility model relates to a digital display board and control circuit board, the digital display board includes digital drive circuit and display countdown number field code, the digital drive circuit is driven by control circuit board and is connected with number field code communication, and digital drive circuit includes the MOS pipe of controlling number field code color and the first singlechip of controlling number field code countdown display. The digital drive circuit further includes a transistor, and the transistor and the MOS pipe are connected with the first singlechip.

2. A countdown timer according to claim 1, wherein, The control circuit board includes a second singlechip, a rectifier circuit, a signal detection circuit, a signal output interface, an RS485 interface, an address dial code, a voltage stabilizing circuit, a photosensitive sensor and a DC power module.

3. A countdown timer according to claim 1, wherein, The second singlechip is connected with the digital display board through the signal output interface, and the RS485 interface and the photosensitive sensor are connected with the second singlechip respectively.

4. A countdown timer according to claim 3, wherein, The second singlechip is connected with the signal detection circuit, and the signal detection circuit includes six photoelectric couplers.

5. A countdown timer according to claim 3, wherein, The rectifier circuit includes six rectifier bridges, and the six rectifier bridges are connected with the six photoelectric couplers one by one.

6. A countdown timer according to claim 3, wherein, The voltage stabilizing circuit is connected with the output end of the DC power module.

7. A countdown timer according to claim 3, wherein, The RS485 interface is connected with a self-recovery fuse.

8. A countdown timer according to claim 3, wherein, The signal output interface includes a power supply positive and negative pole and a serial communication line.

9. A countdown timer according to claim 1, wherein, The number field code includes a red LED, a green LED and a yellow LED.

10. A countdown timer according to claim 1, wherein, The number of the digital drive circuit and the number field code is two.

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