SU1560069A3 - Electrooptical welding assembly - Google Patents

Abstract

This invention relates to light shielding filters, in particular for welding shields or welding goggles. The purpose of the invention is to increase reliability and reduce the effect of interference. The transparency-controlled electro-optical unit is equipped with a controllable light filter 1 on a liquid crystal, a light-sensitive element 5 and an optoelectronic converter 4, which is influenced by an external light or, accordingly, light transmitted by light 1, which, together with the stabilizer 3 and the switching voltage 4, ensure the device autonomy for power supply . The positioning of the transducer 4 in the direction of light transmission behind the transparency-controlled light filter 1 forms a closed transparency control loop for an approximate maintenance of the constant transmitted light intensity with varying illumination of the object, which gives optimal observation conditions determined by the reference potentiometer 6 connected as well as the light-sensitive element 5 to the corresponding input of the differential amplifier 7. 2 C.p. f-ly, 5 ill.

Description

The invention relates to light-protective liltram, in particular for welding shields or welding goggles.

The aim of the invention is to increase reliability and reduce the effect of interference.

FIG. 1 and 2 show the node, circuit solutions; in fig. 3 - the same, an embodiment with a reduced

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the number of circuit elements; in fig. 4 - controlled light filter; in fig. 5 - the same, a variant of execution,

The electro-optical unit contains a controlled light filter 1 on a liquid crystal, an optic converter 2, a stabilizer 3, a voltage converter 4, a photosensitive element 5, a potentiometer 6, a differential amplifier 7, a trigger 8, an analog switch 9, a power amplifier 10, an ultraviolet filter II, infrared filter 12, liquid crystal cells J3 and 14, and polarizers 15-J7.

A controlled light filter 1 on a liquid crystal is connected to a power source for controlling the transparency consisting of an optoelectronic converter 2, which is affected by external light in the direction of the arrow, a stabilizer 3, and also has a switching voltage converter 4. The control circuit contains a photosensitive element 5 as a sensor, which, through a switching regulator switched on with the setpoint set by potentiometer 6, differential amplifier 7 and the trigger 8 switched on after it actuates the analog switch 9 in the power supply circuit. Such an electro-optical node is independent of external power, reliable in operation and

The transparency control keeps the transmitted light in intensity at certain limits approximately constant. Thus, the assembly allows, for example, application for welding purposes to operate at approximately constant intensity of illumination for the user's eyes, while the illumination of the object can vary greatly. The node with a reduced number of circuit elements also allows the transparency to be adjusted with an approximately constant light intensity for the observer. For this, the opto-electronic power converter 2 is located behind the controllable light filter 1 in the incident light. Switching converter 4 voltage is connected directly after the converter. Since the converter 2, with a darkened filter, operates at a low light intensity and therefore has a high internal resistance.

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Motren shunt potentiometer 6 in combination with a high-resistance input of a controlled light filter 1. This design differs at a low cost, sufficient for many purposes, as a regulator.

FIG. Figure 4 shows the construction of a controllable light filter 1 with an optoelectronic converter 2 connected in parallel and the light sensor element 5 turned on after a schematically extended image. The transducer 4 is located just behind the UV filter 11 so that, according to its spectral sensitivity, it can be precisely set with respect to the reflectivity of the sensor, it can optimally limit the activation threshold.

The photosensitive element 5 (Fig. 2) in the direction of the light falling, shown by the arrow, is located behind the controlled light filter 1 on the liquid crystal. At this expense, the control circuit forms a closed transparency control loop with the controlled light filter 1 as the executive body. The differential amplifier 7 operates as a comparison element of a given and actual values with potentiometer 6 as a sensor of a given value. On10

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After this, the power downer 10 feeds the switching voltage converter 4.

The transparency control keeps the transmitted light in intensity at certain limits approximately constant. Thus, the assembly allows, for example, application for welding purposes to operate at approximately constant intensity of illumination for the user's eyes, while the illumination of the object can vary greatly. The node with a reduced number of circuit elements also allows the transparency to be adjusted with an approximately constant light intensity for the observer. For this, the opto-electronic power converter 2 is located behind the controllable light filter 1 in the incident light. Switching converter 4 voltage is connected directly after the converter. Since the transducer 2 with a dark filter operates at a low light intensity and therefore has a high internal resistance

Motren shunt potentiometer 6 in combination with a high-resistance input of a controlled light filter 1. This design differs at a low cost, sufficient for many purposes, as a regulator.

FIG. Figure 4 shows the construction of a controllable light filter 1 with an optoelectronic converter 2 connected in parallel and the light sensor element 5 turned on after a schematically extended image. Transducer 4 is located just behind UV filter 11 so that, according to its spectral sensitivity, it can optimally

It is energy efficient, while the infrared Ailter 12 is turned on after the filter device for thermal protection of the user.

The infrared filter 12 can also be switched on before the controlled light filter I. Otherwise, the controlled light filter 1 on the liquid crystal contains two rotating liquid crystal cells 13 and 14 connected in succession, as well as the corresponding polarizers 15-17.

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The controlled illumination light has two liquid crystal cells 13 and 14 that are connected one after the other, and the optoelectronic converter 2 is installed after the cell 13 and thus receives a relatively large residual intensity of light in a darkened control state, due to which it works more reliably.

Claims (3)

1. An electro-optical node for welding, containing a controlled light filter on a liquid crystal, comprising a first polarizer, located in front of the light filter, and a second polarizer, located behind the light filter and oriented in the same direction as the first polarizer, as well as the control circuit, the output of which is connected to the control input of the light filter, which is also distinguished by the fact that, for the purpose of increasing / 00696 Reliability and reduction of interference, the control circuit contains an optoelectronic converter, the outputs of which are connected to the power terminals of the control circuit, as well as a light-sensitive element behind the light filter, the first output of which is connected to the control input of the control circuit and the second power terminal . ten 2. Welding unit according to claim 1, which is a fact that it contains a second controlled light filter on a liquid crystal, installed behind the first filter, and the photosensitive element of the optoelectronic converter is installed behind the first and in front of the second filter. 3. Welding unit according to claim 1 or 2, characterized in that it contains additional ultraviolet and infrared light filters located in front of the light filter or the first light filter. // J5 / 3 1B f & Г7 Г2 / J / Л / г