CN215219475U - Control circuit of local digital meter - Google Patents

Abstract

A control circuit of an on-site digital meter comprises a singlechip, a power circuit, a signal receiving circuit and a display circuit, wherein the power circuit, the signal receiving circuit and the display circuit are connected with the singlechip; the method is characterized in that: the power supply circuit comprises a power supply port I connected with a pin of the battery mounting groove and a power supply port II connected with an external 24 power supply, the output ends of the power supply port I and the power supply port II are connected with the power supply detection circuit, the tail end of the power supply detection circuit is connected with the power supply switching circuit, and the power supply switching circuit is connected with the single chip microcomputer through the power supply output port after passing through the voltage stabilizing circuit. The utility model realizes dual power supply, so that the instrument of the technical proposal can adapt to various environments without replacement; unnecessary losses are reduced for the user.

Description

Control circuit of local digital meter

Technical Field

The utility model relates to an instrument and meter technical field, concretely relates to control circuit of digit table on spot.

Background

The power supply of the existing digital instrument adopts a single power supply to supply power, and generally adopts an external 24V power supply or a battery to supply power for the instrument.

However, some test sites are not connected with a power supply temporarily, and instruments needing external power supplies cannot be used; if the instrument with the battery for power supply is adopted, the battery needs to be replaced frequently, and the maintenance is very troublesome.

Or when the power is accessed to a later stage site and the data of the instrument needs to be uploaded to an upper computer or a control room, the instrument powered by the battery can not meet the requirement of the power, and the instrument needs to be replaced, so that unnecessary loss is caused.

Disclosure of Invention

In view of the above technical problems, the present technical solution provides a control circuit for an in-situ digital watch, which can effectively solve the above problems.

The utility model discloses a following technical scheme realizes:

a control circuit of an on-site digital meter comprises a singlechip, a power circuit, a signal receiving circuit and a display circuit, wherein the power circuit, the signal receiving circuit and the display circuit are connected with the singlechip; the power supply circuit comprises a power supply port I connected with a pin of the battery mounting groove and a power supply port II connected with an external 24 power supply, the output ends of the power supply port I and the power supply port II are connected with the power supply detection circuit, the tail end of the power supply detection circuit is connected with the power supply switching circuit, and the power supply switching circuit is connected with the single chip microcomputer through the power supply output port after passing through the voltage stabilizing circuit.

Further, the first power port adopts J1 and J2 ports, and J1 and J2 ports output power DVCC; the second power supply port adopts J3 and J4 ports, and J3 and J4 ports output power supply AVCC; the power DVCC and the power AVCC are simultaneously input into the power detection circuit, the power detection circuit detects the power, and when the power detection circuit detects that the external 24V power AVCC exists, the circuit preferentially selects the external 24V power AVCC to supply power for the instrument.

Further, the power supply switching circuit comprises a switch K1 connected to the power supply DVCC, and the power supply DVCC and the power supply AVCC can be automatically switched by a switch K1.

Further, when the power supply detection circuit detects that an external 24V power supply AVCC exists, a K1 switch in the circuit is in an off state; when the power supply detection circuit detects that no external power supply AVCC exists, a K1 switch in the circuit is in a closed state.

Furthermore, the signal receiving circuit comprises a temperature sensor circuit for acquiring temperature and a light sensing circuit for testing the surrounding environment; the temperature sensor circuit and the light sensing circuit are connected with the single chip microcomputer after passing through the signal amplification circuit.

Further, the temperature sensor circuit comprises B20 and U7 ports for connecting a digital temperature sensor, and a J6 port connected with a thermocouple temperature sensor; the output ends of the ports B20, U7 and J6 are respectively connected with the singlechip and the signal amplifying circuit; the user can select digital temperature sensor or thermocouple temperature sensor for use according to the demand in monitored place.

Further, a photoresistor R35 arranged on the top surface of the first PCB is arranged in the light sensing circuit, and a resistor R36, a resistor R37 and a resistor R23 are connected in parallel with the photoresistor R35; the photosensitive resistor R35 is used for receiving the brightness of the surrounding environment of the instrument and sending signals to the single chip microcomputer, and the single chip microcomputer controls the brightness of the display screen through the signals of the photosensitive resistor.

Furthermore, when the light received by the photoresistor R35 is in the "normal" range, the resistor R36 sends out a low level signal, and when the light received by the photoresistor R35 is in the "dark" range, the resistor R36 sends out a high level signal.

Further, when the light received by the photo resistor R35 is in the "normal" range, the resistor R23 sends out a high level signal, and when the light received by the photo resistor R35 is in the "dark" range, the resistor R23 sends out a low level signal.

(III) advantageous effects

The utility model provides a pair of digit table on spot compares with prior art, and it has following beneficial effect:

(1) the technical scheme adopts an external 24V power supply and a battery power supply to supply power for the instrument with double power supplies, so that the instrument can meet the requirements that the site to be monitored is monitored before the construction is complete, and monitored digits are displayed on the site; the remote control system can be directly connected with an external 24V power supply after the site construction is completed in the later period, and can meet the requirement of the 24V power supply for connecting signals to a computer, a control room or an upper computer; the instrument in the technical scheme can adapt to various environments without replacement; unnecessary losses are reduced for the user.

(2) This technical scheme detects the power through power detection circuit, and with realize dual supply automatic switch-over through switch K1. When the power supply detection circuit detects that the external 24V power supply AVCC exists, the circuit preferentially selects the external 24V power supply AVCC to supply power for the instrument. The use of battery power can be reduced and the service time of the battery can be increased.

(3) According to the technical scheme, the brightness of the display screen is controlled by the arrangement of the light sensing circuit and the signal of the light sensing circuit; the display screen has the function of selecting the light switch, the instrument enters a low power consumption mode to display OFF when the light is dark, and the service life of the battery is prolonged by about one time.

(4) In the technical scheme, the double interfaces of the temperature sensor are arranged, so that a user can select a digital temperature sensor or a thermocouple temperature sensor according to the requirement of a monitored site. The instrument of the technical scheme can be further suitable for various environments.

Drawings

Fig. 1 is a schematic diagram of the whole structure of the embodiment 1 of the present invention.

Fig. 2 is a schematic view of the overall structure of the middle housing of the present invention.

Fig. 3 is a top view of the housing of the present invention.

Fig. 4 is a front view of the housing of the present invention.

Fig. 5 is a side view of the housing of the present invention.

Fig. 6 is a schematic view of the overall structure of the middle control panel of the present invention.

Fig. 7 is a schematic block diagram of the overall circuit of the control board according to the present invention.

Fig. 8 is a schematic diagram of a power supply circuit according to the present invention.

Fig. 9 is a schematic diagram of a voltage stabilizing circuit according to the present invention.

Fig. 10 is a circuit diagram of a signal receiving circuit according to the present invention.

Fig. 11 is a circuit diagram of the signal operational amplifier of the present invention.

Fig. 12 is a circuit diagram of the single chip microcomputer of the present invention.

Fig. 13 is a circuit diagram of the key of the present invention.

Fig. 14 is a circuit diagram of a display panel according to the present invention.

The labels in the figures are: the sensor comprises a shell 1, an upper cover 11, a display cover 111, transparent glass 112, a shell body 12, a wire inlet 121, a wire outlet 122, a through hole 123, a lower cover 13, a sensor protective sleeve 2, a cable protective shell 3, a flange 31, a control panel 4, a first PCB 41, a PCB control panel 42, a PCB bottom plate 43, a battery 44, a support pillar 45 and a signal line 5.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The described embodiments are only some, but not all embodiments of the invention. Under the prerequisite that does not deviate from the design concept of the utility model, the ordinary person in the art should fall into the protection scope of the utility model to the various changes and improvements that the technical scheme of the utility model made.

Example 1:

as shown in fig. 1-6, the on-site digital watch comprises a housing 1, a control panel 4 is arranged in the housing 1, and the control panel 4 is detachably and fixedly arranged in the housing 1. The shell 1 comprises a shell body 12 which is arranged in the middle and is communicated up and down, an upper cover 11 and a lower cover 13 which can be opened are respectively arranged on the upper part and the lower part of the shell body 12, and the upper cover 11 and the lower cover 13 are connected with the shell body 12 through threads.

A connection seat for fixing the control panel 4 is integrally fixed on the inner side wall of the shell body 12, and an internal thread hole is formed in the connection seat; the control panel 4 is detachably and fixedly arranged on the inner side of the shell body 12 through a fastener. (conventional techniques are used in this section and are not shown in the drawings).

The control panel 4 comprises a first PCB 41 for fixedly mounting the display screen, a second PCB 42 for fixing the singlechip and the signal connection port, and a third PCB 43 for fixing the battery mounting groove and the power connection port, wherein the first PCB 41, the PCB 42 and the PCB 43 are detachably and fixedly mounted into a whole through four support columns 45, and a certain distance is arranged among the first PCB 41, the PCB 42 and the PCB 43; the plugging operation of the port at the later stage can be facilitated.

In the shell 1, the shell body 12, the upper cover 11 and the lower cover 13 are all made of explosion-proof materials through an explosion-proof process. The top surface of the upper cover 11 of the housing 1 is provided with a transparent display cover for observing data, the transparent display cover comprises a display cover 111 and transparent glass 112, and an O-shaped ring for sealing is arranged between the display cover 111 and the transparent glass 112; a pressing ring is disposed between the transparent display cover and the first PCB 41. The lower cover 13 of the shell is a closed cover body, and a pressing ring is arranged between the lower cover 13 and the PCB bottom plate 43. The threads between the upper cover 11 and the lower cover 13 and the shell body 12 are more than or equal to 10 circles, and the thickness of the threads is more than or equal to 1 cm.

The side wall of the shell body 12 is provided with three through holes communicated with the inside of the shell 1, two of the three through holes are a wire inlet hole 121 and a wire outlet hole 122, and the wire inlet hole 121 and the wire outlet hole 122 are arranged on one side of the shell body 12 and are arranged oppositely; one of the two through holes is used for distributing a power line connected with an external 24V power supply, and the other through hole is used for distributing a signal connecting line for signal transmission with external equipment. And a third through hole 123 for distributing signal transmission lines connected with the sensor is arranged on the other side of the shell body 12.

A sensor protective sleeve 2 is detachably and fixedly connected to the side wall of the shell body 12 at the position of the third through hole 123 through threads, and a temperature sensor is installed in the sensor protective sleeve 2; a detachably fixed cable protection housing 3 is arranged between the sensor protection sleeve 2 and the housing body 12. A flange 31 for limiting and fixing is fixed in the middle of the cable protection shell 3, and external threads for fixing are arranged at the bottom of the flange 31; the external thread is matched with the internal thread of the fixing hole of the site construction site.

The sensor protective sleeve 2, the cable protective shell 3 and the shell 1 are made of explosion-proof materials through an explosion-proof process; and threads among the sensor protective sleeve 2, the cable protective shell 3 and the shell 1 are more than or equal to 10 circles, and the thickness of the threads is more than or equal to 1 cm.

The electronic components on the first PCB 41, the PCB control board 42 and the PCB bottom board 43 are all fixed on the first PCB 41, the PCB control board 42 and the PCB bottom board 43 by using a mounting process.

The first PCB 41 is provided with a display circuit mainly including a display screen, an adjusting switch connected with the single chip, and a power switch connected with a power supply. The display screen adopts a liquid crystal display screen with a large field and a wide visual angle, and the reading is striking and visual.

The adjusting switch and the power switch can be magnetic induction switches or key switches. When the instrument was as the manometer, adjusting switch and switch adopted the magnetic induction switch, can be convenient for fast zero setting, and magnetic induction switch K3 position is placed to magnet about 2 seconds, and the display screen digit disappears, moves away magnet this moment, and fast zero setting is accomplished promptly to the instrument. When the quick zero setting is carried out, the process pressure is determined to be zero, and the absolute pressure meter is closed to carry out quick zero setting when leaving a factory.

The instrument does not use external power supply, but when adopting the built-in battery power supply of instrument, if need shut down, magnet placement magnetic induction switch K2 position about 2 seconds, after the display screen shows OFF, remove the magnet this moment, the instrument shows that the digit disappears and shuts down. When the instrument is started, the magnet is placed at the position of the magnetic induction switch K2, the display screen displays on, at the moment, the magnet is removed, and the instrument is normally started to display the current pressure measurement value.

When the instrument is used as a thermometer, the adjusting switch and the power switch adopt key switches, and the key switches comprise an S key, a mobile key and a reduced ˄ key. The key mode on-off operation is as follows, the end cover provided with the glass is rotated to be opened, the panel is provided with three keys, namely an S key, a mobile key and a ˄ key are respectively arranged. The mobile phone is powered off by pressing the shift key for a long time and powered on by pressing the shift key for a short time.

The PCB control board 42 of the second layer is provided with a control circuit mainly including a single chip, a signal processing circuit, and a signal connection port connected to an external device. The signal connection port comprises a display screen connection port connected with the display screen, and a signal input port and a signal output port connected with external equipment. The single chip microcomputer is connected with the temperature sensor or the pressure sensor through a wire and used for receiving data of the temperature sensor or the pressure sensor, integrating the data and displaying the detected data through the display screen. Meanwhile, the monitoring device is in signal connection with external equipment through a signal connection port and a signal wire, and monitoring data are uploaded to an upper computer or a control room through the external equipment.

The third layer of the PCB bottom plate 43 is provided with a power circuit which mainly comprises a battery mounting groove and a power connection port; the battery mounting groove is fixedly mounted on the bottom surface of the PCB bottom plate 43 through a fastener, and the battery mounting groove is in signal connection with the PCB bottom plate 43 through pins. And a lithium battery 5 is arranged in the battery mounting groove.

The power connection port comprises a first power port (J1 and J2) connected with the battery installation groove and a second power port (J3 and J4) connected with an external power supply, and the second power port (J3 and J4) is connected with external power equipment through a power line.

And a power detection circuit, a power switching circuit and a voltage stabilizing circuit are arranged between the first power port (J1 and J2) and the second power port (J3 and J4) and the single chip microcomputer, and the first power port (J1 and J2) and the second power port (J3 and J4) can be automatically switched.

When the power supply detection circuit detects that an external 24V power supply exists, the circuit preferentially selects the external 24V power supply to supply power to the instrument; when the power supply detection circuit detects that no external power supply exists, the single chip microcomputer selects a battery through the first power supply port to supply power. When an external power supply is used for supplying power, the external power supply adopts 24V direct current voltage and simultaneously remotely transmits 4-20mA signals.

Example 2:

as shown in fig. 7, the control circuit of the local digital meter comprises a single chip microcomputer, and a power circuit, a signal receiving circuit and a display circuit which are connected with the single chip microcomputer; the power supply circuit comprises a power supply port I connected with a pin of the battery mounting groove and a power supply port II connected with an external 24 power supply, the output ends of the power supply port I and the power supply port II are connected with the power supply detection circuit, the tail end of the power supply detection circuit is connected with the power supply switching circuit, and the power supply switching circuit is connected with the single chip microcomputer through the power supply output port after passing through the voltage stabilizing circuit.

And a key circuit is arranged between the power circuit and the singlechip, and the switch, the zero setting and the signal adjustment of the digital meter can be controlled by the key circuit.

The signal receiving circuit comprises a temperature sensor circuit for acquiring temperature. And the temperature sensor circuit and the light sensing circuit are connected with the singlechip through the signal amplification circuit.

The specific circuit connection relationship is as follows:

as shown in fig. 8, in the present embodiment, the first power ports connected to the battery mounting groove are J1 and J2 ports, and the J1 and J2 ports output power DVCC. The second power port connected with the external power supply adopts J3 and J4 ports, and J3 and J4 ports output power supply AVCC. And the power supply DVCC and the power supply AVCC are simultaneously input into the power supply detection circuit to detect the power supply.

When the power supply detection circuit detects that an external 24V power supply AVCC exists, the circuit preferentially selects the external 24V power supply AVCC to supply power to the instrument; the K1 switch in the circuit is in an open state at this time. When an external power supply is used for supplying power, the external power supply adopts 24V direct current voltage and simultaneously remotely transmits 4-20mA signals.

When the power supply detection circuit detects that no external power supply AVCC is available, the single chip microcomputer selects a power supply DVCC at a first power supply port to supply power. The K1 switch in the circuit is in a closed state at this time. A power supply DVCC is connected into the circuit.

And a power supply detection circuit, a power supply switching circuit and a voltage stabilizing circuit are arranged between the single chip microcomputer and the power supply, and the first power supply port (J1 and J2) and the second power supply port (J3 and J4) can be automatically switched through a K1 switch.

The output end AVSS of the power supply AVCC is connected to the adapter port adapter 7X2, and the output end DVSS of the power supply DVCC is connected to the adapter port adapter 7X 2; is connected with the singlechip through a switching port HEADER 7X 2.

As shown in fig. 9, the output end of the power switching circuit is connected to a voltage stabilizing circuit, which uses a voltage stabilizing conversion chip with model number SP-78230 to convert the power into a 3.3V power, and the power is connected to the circuit to supply power to the meter.

As shown in fig. 10, the signal receiving circuit includes a temperature sensor circuit for collecting temperature, the temperature sensor circuit employs B20 and U7 ports to connect with the temperature sensor, and B20 and U7 ports to connect with the digital temperature sensor. In this embodiment, the temperature sensor is a temperature sensor of a model DS18B20, and is connected to the single chip microcomputer through a signal output terminal DQ.

The signal output end K-3V of the digital temperature sensor is connected with the signal switching circuit and then connected with the signal amplifying circuit through a 6out interface in the signal switching circuit.

The temperature sensor can also select a thermocouple temperature sensor, when the temperature sensor is the thermocouple temperature sensor, the thermocouple temperature sensor is connected with the signal amplification circuit through the J6 port, and then the signal is output to the single chip microcomputer after passing through the signal amplification circuit.

The signal receiving circuit also comprises a light sensing circuit for testing the surrounding environment, and the light sensing circuit is mainly formed by a circuit surrounding the photoresistor R35; the photoresistor R35 is mounted on the top surface of the first PCB board; for receiving the brightness of the environment surrounding the meter. The photoresistor R35 is connected in parallel with a resistor R36, a resistor R37 and a resistor R23.

When the resistor R36 is used, a low level signal is sent out when the light received by the photo-resistor R35 is in the "normal" range value, and a high level signal is sent out when the light received by the photo-resistor R35 is in the "dark" range value.

When the resistor R23 is used, a high level signal is sent out when the light received by the photo-resistor R35 is in the "normal" range value, and a low level signal is sent out when the light received by the photo-resistor R35 is in the "dark" range value.

The signal in the LIGHT sensing circuit is connected with the singlechip through an output end LIGHT. And then is connected with the signal amplifying circuit through a 6out interface in the signal switching circuit.

As shown in fig. 11, the signal amplifying circuit adopts an operational amplifier chip with model number SP-333, a first pin of the SP-333 is connected with a 6out interface in the switching circuit, and the signal of the digital temperature sensor and the optical signal in the optical sensing circuit are amplified and then transmitted to the single chip microcomputer.

As shown in fig. 12, the single chip microcomputer is a control chip with a model number of 430F4270, and pins 1 to 7 of the control chip are connected to a adaptor port HEADER 7X2 in the power supply circuit. The 8 th pin to the 9 th pin of the control chip are connected with a crystal oscillator circuit. And the 18 th pin of the control chip is connected with the digital temperature sensor. The 10 th pin and the 21 st pin of the control chip are connected with light sensing power. Pins 12-14 and 22 of the control chip are connected with the output end of the signal amplifying circuit. The 17 th pin and 19-20 th pins of the control chip are connected with the key circuit. The 31 st to 48 th pins of the control chip are connected with the display screen. Pins 25 to 28 of the control chip are connected to the connection port J9. The control chip can be connected with the upper computer through a port J9 and carries out signal transmission with the upper computer.

As shown in fig. 13, one end of the key circuit is connected to a power supply, and the other end is connected to the single chip microcomputer through a port J11.

As shown in fig. 14, the display circuit adopts a display screen with a model number of LCD-2014.

Claims (9)

1. A control circuit of an on-site digital meter comprises a singlechip, a power circuit, a signal receiving circuit and a display circuit, wherein the power circuit, the signal receiving circuit and the display circuit are connected with the singlechip; the method is characterized in that: the power supply circuit comprises a power supply port I connected with a pin of the battery mounting groove and a power supply port II connected with an external 24 power supply, the output ends of the power supply port I and the power supply port II are connected with the power supply detection circuit, the tail end of the power supply detection circuit is connected with the power supply switching circuit, and the power supply switching circuit is connected with the single chip microcomputer through the power supply output port after passing through the voltage stabilizing circuit.

2. A control circuit for an in-place digital watch as claimed in claim 1, wherein: the first power supply port adopts J1 and J2 ports, and the J1 and J2 ports output a power supply DVCC; the second power supply port adopts J3 and J4 ports, and J3 and J4 ports output power supply AVCC; the power DVCC and the power AVCC are simultaneously input into the power detection circuit, the power detection circuit detects the power, and when the power detection circuit detects that the external 24V power AVCC exists, the circuit preferentially selects the external 24V power AVCC to supply power for the instrument.

3. A control circuit for an in-situ digital watch according to claim 1 or 2, characterised in that: the power supply switching circuit comprises a switch K1 connected with a power supply DVCC, and the power supply DVCC and the power supply AVCC can be automatically switched by a K1 switch.

4. A control circuit for an in-place digital watch as claimed in claim 3, wherein: when the power supply detection circuit detects that an external 24V power supply AVCC exists, a K1 switch in the circuit is in an off state; when the power supply detection circuit detects that no external power supply AVCC exists, a K1 switch in the circuit is in a closed state.

5. A control circuit for an in-place digital watch as claimed in claim 1, wherein: the signal receiving circuit comprises a temperature sensor circuit for collecting temperature and a light sensing circuit for testing the surrounding environment; the temperature sensor circuit and the light sensing circuit are connected with the single chip microcomputer after passing through the signal amplification circuit.

6. A control circuit for an in-place digital watch as claimed in claim 5, wherein: the temperature sensor circuit comprises B20 and U7 ports for connecting a digital temperature sensor, and a J6 port connected with a thermocouple temperature sensor; the output ends of the ports B20, U7 and J6 are respectively connected with the singlechip and the signal amplifying circuit; the user can select digital temperature sensor or thermocouple temperature sensor for use according to the demand in monitored place.

7. A control circuit for an in-place digital watch as claimed in claim 5, wherein: the light sensing circuit is internally provided with a photosensitive resistor R35 arranged on the top surface of the first PCB, and the photosensitive resistor R35 is connected with a resistor R36, a resistor R37 and a resistor R23 in parallel; the photosensitive resistor R35 is used for receiving the brightness of the surrounding environment of the instrument and sending signals to the single chip microcomputer, and the single chip microcomputer controls the brightness of the display screen through the signals of the photosensitive resistor.

8. A control circuit for an in-place digital watch as claimed in claim 7, wherein: when the light received by the photoresistor R35 is in the 'normal' range value, the resistor R36 sends out a low-level signal, and if the light received by the photoresistor R35 is in the 'dark' range value, the resistor R36 sends out a high-level signal.

9. A control circuit for an in-place digital watch as claimed in claim 7, wherein: when the light received by the photoresistor R35 is in the 'normal' range, the resistor R23 sends out a high-level signal, and if the light received by the photoresistor R35 is in the 'dark' range, the resistor R23 sends out a low-level signal.

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