CN201119949Y - An automatic darkening liquid crystal welding goggles controlled by a single-chip computer system - Google Patents

Abstract

The utility model discloses an automatic dimming liquid crystal welding goggle controlled by a single-chip microcomputer system, which belongs to the field of welding equipment. It includes a shell, a single-chip microcomputer, and a power interface electrically connected with it, a trigger circuit, a signal output circuit; a photosensitive tube electrically connected with the trigger circuit, and a liquid crystal lens group electrically connected with the signal output circuit. Thermistor, sensitivity adjustment knob, shading number adjustment knob, delay switch, temperature compensation circuit, voltage boosting circuit and reserved ports are also arranged on the single chip microcomputer. The utility model can change the degree of dark state according to the shading number set in advance with the change of the light intensity produced in the welding process within a wide temperature range from -10°C to +60°C. Because the single-chip microcomputer application program is used to control the entire circuit, the circuit triggered for a long time can also be maintained at a stable value. At the same time, the reserved port on the single-chip microcomputer greatly enhances the scalability of the utility model.

Description

An automatic darkening liquid crystal welding goggles controlled by a single-chip computer system

technical field

The utility model relates to a liquid crystal welding goggle controlled by a single-chip microcomputer system. In particular, it relates to a liquid crystal goggle that can change the dark state according to the preset shading number according to the change of the light intensity generated in the welding process in a wide temperature range from -10°C to +60°C.

Background technique

At present, the generally used welding goggles are only made of dark plastic or glass, or light filters are used to block the arc light during welding. When the welding arc starts, under the strong arc light, the welder can see the workpiece, welding tongs and working environment, etc., but before and after the welding arc starts, under the natural light, the welder's vision is blocked by dark goggles The lens is blocked, and the eyes are often pitch black. You can only operate by groping, or take off the goggles, which is neither convenient nor safe. Even in the process of welding, the intensity of the arc light is different, and the temperature of the working environment of the user is different. The user can only use welding goggles with a single degree of darkness in the changing environment, which greatly reduces the welding time. The quality, efficiency, and the protection of the user's eyes are not fully protected.

Contents of the invention

In order to overcome the deficiency that the existing welding goggles cannot adjust and stabilize the light and dark state of the goggle lens with the change of external environmental factors such as ambient temperature and light intensity, the utility model provides a liquid crystal welding goggle controlled by a single-chip microcomputer system. eyepiece.

The technical scheme of the utility model is summarized as follows:

An automatic dimming liquid crystal welding goggle controlled by a single-chip computer system, including a shell, a power interface, a photosensitive tube, a trigger circuit, a single-chip computer, a signal output circuit, and a liquid crystal lens group; wherein the single-chip electromechanical connection is connected to the power supply interface, the trigger circuit and the signal output circuit; The photosensitive tube is electrically connected to the trigger circuit; the liquid crystal lens group is electrically connected to the signal output circuit.

The above-mentioned liquid crystal lens group is composed of colorless glass, two (or one) liquid crystal sheets and a filter. The colorless glass and the filter play the role of protecting the liquid crystal, and the filter also plays the role of cutting off ultraviolet and infrared rays. The liquid crystal sheet is also called the liquid crystal light valve. When it is pressurized, the liquid crystal molecules inside the liquid crystal sheet start to twist and rotate, so that the liquid crystal sheet changes from bright to dark from the appearance, that is, the shading number of the goggles changes from bright to dark. into a dark state.

Further, the thermistor is electrically connected to the single-chip microcomputer to detect changes in the external environment temperature, so that the lens group can adjust the temperature of the liquid crystal lens according to the operating environment temperature within a wide temperature range from -10°C to +60°C. The voltage stabilizes the dark state of the lens group to achieve good protection for the user's eyes.

The single-chip microcomputer is also electrically connected with a series of user-settable adjustment switches, including a sensitivity adjustment knob, a shading signal adjustment knob and a delay switch.

The sensitivity adjustment knob is used to linearly adjust the sensitivity of the photosensitive tube to the intensity of the external trigger light source. Increasing the sensitivity will allow a weaker optical signal to trigger the system. This knob is a linear adjustment and can be rotated arbitrarily within half a circle according to the actual situation.

The shading number adjustment knob is used to select the corresponding shading number to obtain different dark state effects. This knob can be set to five levels of 9, 10, 11, 12, and 13. The user can manually select the corresponding shading by referring to the use selection of manual arc welding filter in Table 3 in "Welding Goggles and Masks GB 3609.1-83" number to get the effect of different dark state levels.

The delay switch is used to set the length of time for the LCD lens group to change from a dark state to a bright state after the trigger signal disappears. This knob can be set to fast (fast) and slow (slow).

The single-chip microcomputer is also electrically connected with a boost circuit, which can apply a 24V high-level voltage to the liquid crystal lens group, so that the goggles can be automatically and rapidly changed from weak to strong at the moment of welding. The light state turns into a dark state, and the transition time is only 0.3-0.5 milliseconds. The boost circuit is composed of a diode 6-times voltage rectifier circuit, and the control part composed of a voltage dividing resistor and a MOS tube circuit can adjust the 5V system voltage to the required 24V high level voltage by controlling the high level charging pulse output by the microcontroller .

The single-chip microcomputer is also electrically connected with a temperature compensation circuit, which outputs temperature compensation voltage to the liquid crystal lens group. The microcontroller controls the temperature compensation circuit to adjust the pulse output voltage according to the ambient temperature detected by the thermistor and the compensation voltage corresponding to the temperature in the temperature compensation table program input in advance.

A reserved port is also set on the single-chip microcomputer to provide possibility for secondary development. The functions currently developed include: digital display of shading number, power notification, power outage reminder, etc.

Furthermore, the utility model is powered by a lithium battery, and a silicon photocell is provided at the same time to prolong the service life of the lithium battery. The power interface is electrically connected to a power supply voltage stabilizing chip, the power supply voltage stabilizing chip is electrically connected to a lithium battery, and the lithium battery is electrically connected to a silicon photovoltaic cell. The power regulator chip is directly powered by a lithium battery. When the ambient light is strong enough (>10 lux), the silicon photovoltaic cell outputs current to charge the lithium battery, and the charging current is determined by the light intensity. When the ambient light is insufficient (<10 lux), the output current of the silicon photovoltaic cell is small. At this time, the power regulator chip is in the off state, so that it does not output power, and the whole system enters the non-working state.

Still further, the photosensitive tube described in the utility model is preferably an infrared photosensitive tube.

Compared with the prior art, the utility model has the beneficial effects of:

The single-chip microcomputer application program is used to control the entire circuit, which can maintain a stable value for the circuit triggered for a long time. The use of the new model can quickly change the liquid crystal lens group from a bright state to a dark state in a wide temperature range from -10°C to +60°C, and can protect welding workers more practically, stably, accurately and effectively Eyes, to avoid damage from harmful light radiation. And because the single-chip microcomputer is used as the core of the circuit control system, the sufficient space in the single-chip microcomputer can reserve a certain program space and external interface for other functions attached to the lens group or welding goggles using the lens group, which greatly enhances the The scalability of the utility model.

Description of drawings

Fig. 1. the electrical connection circuit diagram of each port part of the single-chip microcomputer of the utility model embodiment.

Fig. 2. The schematic diagram of the power supply circuit of the utility model embodiment.

Fig. 3. The schematic diagram of the trigger circuit of the embodiment of the utility model.

Fig. 4. The principle diagram of the boost circuit of the utility model embodiment.

Fig. 5. The schematic circuit diagram of sensitivity adjustment, shading number adjustment, and delay time conversion of the utility model embodiment.

Fig. 6 is a schematic circuit diagram of the liquid crystal lens group receiving voltage in the embodiment of the utility model.

Fig. 7. The block diagram of the circuit principle of the utility model.

Fig. 8. Schematic diagram of the liquid crystal lens group of the utility model.

Figure 9. Front view of the embodiment of the utility model.

Figure 10. The reverse schematic diagram of the embodiment of the utility model.

In Figure 1-10:

1. Temperature reading voltage element; 2. Shading number voltage acceleration charging element; 3. High-level active element; 4. Shading number voltage PWM charging element; 5. High-level PWM charging element; 6. External trigger element; 7 .Reset component; 8. Single-chip power supply grounding component; 9. Shading number setting component; 10. Shading number voltage detection component; 11. LCD pulse output B port; 12. LCD pulse output A port; 13. Single-chip power supply; 14. OSC1 ; 15. OSCO; 16. Reserved port; 17. Photosensitive tube trigger element; 18. High level cut-off element; 19. Delay selection element; 23. Shading adjustment knob; 24. Delay switch; 25. Photosensitive tube; 26. Trigger circuit; 27. Thermistor; 28. Temperature compensation voltage; 29. Pulse output voltage; 30. Boost circuit; 31. Liquid crystal Lens group; 32. Silicon photocell; 33. Lithium battery; 34. Power regulator chip; 35. Colorless glass; 36. Liquid crystal sheet; 37. Optical filter; 38. Liquid crystal electrode; 39. Shell.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

The single chip microcomputer 21 is electrically connected with the sensitivity adjustment knob 22, the shading number adjustment knob 23, the delay switch 24, the trigger circuit 26, the thermistor 27, the signal output circuit 29, the temperature compensation circuit 28, the boost circuit 30 and the power supply regulator chip 34 The photosensitive tube 25 is electrically connected with the trigger circuit 26; the liquid crystal lens group 31 is electrically connected with the signal output circuit 29, the temperature compensation circuit 28 and the voltage boosting circuit 30 simultaneously; The lithium battery 33 is electrically connected.

The liquid crystal lens group 31 comprises colorless glass 35, liquid crystal sheet 36, optical filter 37;

The above-mentioned components are all arranged in the casing 39 .

The circuit is triggered to start after receiving the light intensity signal (generally greater than 10 lux) detected by the silicon photocell 32, and the single-chip microcomputer system is in a standby state.

When not in use, the sensitivity adjustment knob 22 is set at the minus sign position, indicating that the sensitivity is zero; the shading sign knob 23 is at the No. 9 position, indicating the degree of darkening of the liquid crystal lens group. As the value of the shading number increases, the degree of darkening of the liquid crystal lens group also increases, that is, the greater the value of the shading number, the greater the degree of darkening of the liquid crystal lens group. Time-delay switch 24 is selected on the position of fast (quick), and expression is when external trigger signal disappears, and liquid crystal lens group becomes the shorter used time of bright state by dark state. The difference between fast and slow delay time of the utility model is only 0.2 milliseconds.

During use, the sensitivity adjustment knob 22 is first rotated clockwise, usually by 90 degrees. When the infrared photosensitive tube 25 detects that there is strong light outside, the signal is transmitted to the trigger circuit 26, and the trigger circuit gives a trigger signal to the single-chip microcomputer 21, and the single-chip microcomputer 21 starts to work. The single-chip microcomputer 21 performs data processing and operation according to the relevant data set by the sensitivity adjustment knob 22 , the shading number adjustment knob 23 and the delay switch 24 .

Single-chip microcomputer 21 exports three control signals:

The first one is to drive the signal output circuit 29, and the single-chip computer controls the signal output circuit 29 to adjust the voltage value of the pulse output voltage applied to the liquid crystal lens group, so that it reaches the voltage corresponding to the shading number set by the shading number adjustment knob Value, this voltage value is the base voltage value for darkening the liquid crystal lens group.

The second is to drive the temperature compensation circuit 28, and the temperature compensation circuit is controlled by the single-chip microcomputer to output the temperature compensation voltage to the liquid crystal lens group. The thermistor 27 detects the temperature and transmits the data to the single-chip microcomputer 21, and the single-chip microcomputer 21 controls the temperature compensation circuit to make corresponding adjustments to the pulse output voltage according to the compensation voltage corresponding to the temperature in the previously input temperature compensation table program.

The third is to drive the booster circuit 30, the booster circuit is controlled by the microcontroller to output a high-level voltage of 24V to the liquid crystal lens group, in order to add the system voltage (5V) to a rather high level (24V), To speed up the transformation speed of the liquid crystal lens group. The boost circuit is composed of diode 6 times voltage rectifier circuit. The control part composed of voltage dividing resistor and MOS tube circuit adjusts the 5V system voltage to the required high level (24V) by controlling the high level charging pulse output by the microcontroller.

After the liquid crystal lens group 31 receives the temperature-adjusted pulse output voltage driven by the single-chip microcomputer 21 and the high-level voltage of the booster circuit 30, the liquid crystal light valve is reversed, and the liquid crystal lens group is based on the value of different shading numbers, refer to the formula :

N(Ev)＝2.93+2.25log(Ev/lx)

Among them: Ev represents the light intensity, the unit is lux; N(Ev) represents the corresponding shading number under the light intensity (selected from: European standard BS EN379: 2003)

to determine the degree of darkening, and start to play the role of eye protection. The time of the whole dimming process is about 0.3 milliseconds.

The power supply of the whole circuit is provided by the lithium battery 33, and the silicon photoelectric battery 32 can effectively prolong the service life of the lithium battery 33. During the working process of the welding goggles, when the light of the external environment is strong, the silicon photovoltaic cell becomes an important power supply by absorbing the external light intensity, which charges the lithium battery and prolongs the service time of the lithium battery. When the light intensity of the external ambient light is less than 10 lux, the system power is automatically turned off, reducing the power loss of the lithium battery.

Claims (10)

1. An automatic dimming liquid crystal welding goggle controlled by a single-chip computer system, including a shell, a power interface, a photosensitive tube, a trigger circuit, a single-chip computer, a signal output circuit, and a liquid crystal lens group; wherein the single-chip electromechanical connection power supply interface, trigger circuit and signal output circuit; the photosensitive tube is electrically connected to the trigger circuit; the liquid crystal lens group is electrically connected to the signal output circuit. 2. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system as claimed in claim 1, wherein the single-chip microcomputer is electrically connected to a thermistor. 3. The automatic darkening liquid crystal welding goggles controlled by the single-chip microcomputer system as claimed in claim 1, wherein the single-chip electromechanical connection user can set the adjustment switch, including a sensitivity adjustment knob, a shading number adjustment knob, an extension time switch; The sensitivity adjustment knob linearly adjusts the sensitivity of the photosensitive tube to the intensity of the external trigger light source; The shading number adjustment knob adjusts the use effect of different dark state degrees of the liquid crystal lens group; The delay switch sets the length of time for the liquid crystal lens group to change from a dark state to a bright state after the trigger signal disappears. 4. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system according to claim 1, wherein the single-chip microcomputer is electrically connected to a boost circuit, and the boost circuit is electrically connected to a liquid crystal lens group. 5. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system according to claim 1, wherein the single-chip microcomputer is electrically connected to a temperature compensation circuit, and the temperature compensation circuit is electrically connected to a liquid crystal lens group. 6. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system according to claim 1, characterized in that, the single-chip microcomputer is also provided with a reserved port. 7. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system as claimed in claim 1, wherein the power interface is electrically connected to a power supply voltage stabilizing chip, and the power supply voltage stabilizing chip is electrically connected to a lithium battery, and the lithium battery is electrically connected to a silicon photocell. 8. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system according to claim 1, wherein the photosensitive tube is an infrared photosensitive tube. 9. The automatic darkening liquid crystal welding goggles controlled by a single-chip microcomputer system as claimed in claim 4, wherein the high-level voltage output by the booster circuit is 24V. 10. The self-darkening liquid crystal welding goggles controlled by a single-chip microcomputer system according to claim 7, wherein the power supply voltage stabilization chip is in an off state when the light intensity of the external environment is less than 10 lux.

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