Electromechanical relays are recognized as reliable, robust low-cost devices. The amount of manufacturing of relays is increasing day by day, and it has been successfully used in myriad applications for signal and energy distribution. Even in the harshest environmental conditions, it still has good robustness and reliability. Various relay types cover a wide range of switching loads, from μV and μA to hundreds of A and up to 500V. Moreover, the relay has a very low resistance (mΩ) in the energized state and a very high insulation resistance (GΩ) in the de-energized state, both of which are suitable for load circuits and control circuits as well as open-circuit switching paths.

The relay has a large overload capacity in terms of allowable voltage, current or temperature. Although the relay has very good physical characteristics, there are some additional requirements. The PCB footprint must be as small as possible and the relay should be splash-proof (wash-proof or weather-proof), or even completely sealed. The new design can not only meet all these requirements, but also improve reliability. Future innovations in relay technology will further enable smaller designs without changing the switching characteristics.

Material cost relays require the use of many raw materials, such as copper for the manufacture of coils or current-carrying parts, noble metals for the production of switching contacts (eg gold, silver and palladium), iron for magnetic circuits, And the plastic used to create the insulation system. The cost of these raw materials has risen significantly in recent years, and the cost of some materials has increased several times. The increase in the cost of silver is particularly serious because there is currently no practical material that can replace silver in switchgear.

One of the main reasons for the great success of miniaturized electromechanical relays is that the relay industry can meet the needs of the electronics industry, telecommunications and automotive electronics equipment through new, miniaturized design innovations (Figure 1). The situation of general-purpose and power relays is more troublesome. The standardized pin layout and necessary air and leakage current paths make the miniaturization design of these relays more difficult, and even hinder the development of miniaturization to some extent. The main challenge in the miniaturization design of relays is to increase the switching capability while reducing the physical size.
Fig. 1: Miniaturization of signal relays in the past 40 years (Generation 1 to 4).

In relay miniaturization design, many constantly changing factors must be considered: maintaining contact reliability in the event of reduced contact force and breaking force; protection of relays from internal and external contamination; material change and contact corrosion The resulting closing force is reduced; in spite of the reduction in physical size, the insulation performance still improves; thermal performance, self-heating and performance at elevated ambient temperatures; longer service life and higher switching capacity; higher Reliability requirements; limitations imposed by manufacturing technology.

New technologies and new concepts will also lead to great innovation in relay technology in the future.

Table 1 shows that the size of the signal relay is continuously shrinking. Although the size is significantly reduced, coil power consumption and switching capacity are almost the same, dielectric characteristics have been improved, switching time has also been significantly shortened, but the thermal resistance has increased.
Table 1: Key characteristics of 2nd to 4th generation signal relays.

The following are some of the factors that can be used to improve the characteristics while reducing the size of the relay.

Design: All miniature relays use polarized magnetic circuits. This feature allows the physical size to be reduced while also supporting bistable switching characteristics. Coil coating allows significantly reduced relay gap and leakage current paths. The use of an airtight enclosure is another advantage, which is to optimally protect the interior of the relay from external contamination, thereby reducing the minimum contact force required.

Materials: In the miniaturization design process, the ratio of volume to surface area will deteriorate, which will lead to increased thermal resistance. In this case, if you still want to maintain good contact reliability, you need to improve the characteristics of the insulation material used. In order to be able to provide the same or even higher reliability, it is necessary to significantly improve the thermal stability and the exhaust characteristics of the insulating material.

The use of copper material is also very important. The higher the conductivity, the more it is allowed to reduce the necessary cross-section and the smaller the physical shape. For the spring material used, the relaxation at high temperatures is very important.

Process: The miniaturization design puts forward higher requirements on the accuracy of the components used in the relay and the precision of the assembly process. Only when both are controlled can the smaller physical size be effectively achieved. Smaller tolerances in the manufacturing process also result in less dispersion of switching characteristics. The smaller physical dimensions require fully automated production to systematically eliminate human factors during assembly and testing.

The larger dielectric strength design can increase the dielectric strength. This sounds reasonable, but it is not necessarily correct in every situation. As shown in Figure 2, compared to the 3rd generation relay, the dielectric strength of the 4th generation product has significantly increased. This improvement in coil-to-contact and in the open switch path can be achieved first by coating the coils, separating the drive from the switching chamber, using an airtight enclosure and a suitable inert gas.
Figure 2: Comparison of dielectric strength of 3rd and 4th generation signal relays.

With these measures, although the physical size is reduced by 2/3, the dielectric properties can still be enhanced by 50%.

Switching Capability Many people believe that larger designs can handle larger switching loads and, therefore, longer service life. As the example shown in Figure 3, the fact is not necessarily the case. As can be seen from Figure 3, the 4th-generation relay, which is much smaller than the 3rd-generation relay, can achieve much higher switching performance. The 3rd-generation relays can only achieve just over 200,000 switching operations, while the 4th generation relays can still operate normally after more than 600,000 switching operations. The miniaturization design can improve the switching characteristics because it has a smaller moving mass, less energetic bouncing, a generally faster switching process, and a shorter arc duration resulting therefrom.
Figure 3: Switching capability of the 3rd and 4th generation signal relays (AC voltage 24V, energizing current 5A, off-current sensing current 1A). The contact voltage is limited to 80V by a varistor.

Switching Noise In many applications, especially in automotive or residential environments, acoustic switching noise will be perceived as interference. The miniaturized design has much lighter moving mass and therefore can greatly reduce switching noise. The average noise level generated by the 2nd generation signal relay is 53.5dB (Figure 4), and it can be reduced to 39.6dB for the 3rd generation product, while the noise of the 4th generation relay can be reduced to 28.2dB. Noise levels below 30dB are generally not noticeable even in quiet rooms such as bedrooms.
Figure 4: The average and maximum values ​​of the switching noise from the 2nd generation to the 4th generation relays show a decreasing trend.

Prospects Electromechanical relays have been successfully marketed for several decades and will continue to be with us faithfully in the future. This relay is highly reliable, robust, and very cost-effective, and it is very easy to use. In modern electronic devices, they are used more and more widely. Contrary to some predictions, it has not been replaced by semiconductor devices so far, but it has coexisted with it peacefully.

Laser Cutting Machine

Overview of the UTECH CO2 Laser Cutter


Product Description:

CO2 laser engraver is special for some vertical materials, it mainly used in the vertical tomb industry, this machine can be fixed onto the tomb for some engraving work, also can do some normal cutting and engraving work.

Applicable materials:
Rubber, Marble, granite, jeans, fabric, acrylic, MDF, wood, bamboo, organic glass, crystal, plastic, garments, paper, leather, rubber, ceramic, glass and other non-metal materials, etc.

Applicable industries:

Advertisement, gift, shoes, toys, computers, garments, model cutting, building, packaging, paper industry, etc.

laser cutting machine for wood acrylic MDF


wood laser cutting machine

jeans laser cutting machine





Advantages of UTECH Laser Cutting Machine:


1. Ball screw transmission
Compared with belt transmission , high precision with fast speed.
2. Stepper motor and river
Standard machine equipped with stepper motor and driver, also can choose hybrid or other servo motor and driver.
3. Ruida 6332M control system Controller
1) Original new version Ruida 6332M control system, support DSP control.
2) High speed USB data transmission interface, download speed is up to 500kb/s
3) The control panel has 12 language for optional,such as Chinese,English,French, Portuguese, Spanish, Russian, German, Korean,Japanese and so on.
4) It supports multiple graphic formats, such as PLT / DXF / BMP / JPG / GIF / PGN / TIF and so on.
5) This machine is equipped with Control System for CorelDraw/AutoCAD and other advance software.
6) Very easy-operating control board and you can also see the engraving path from the control board.
4. Professional Laser headJust one year time,we have improve the laser head three times ,many factory is still use the first
or second one.
At present the latest generation is the most perfect of laser head, compared to the previous two generations, it has many advantages ,such as higher precision, better stability,more convenient to adjust.
And it is also the most popular design for customers.
5. Co2 Laser Tube ( Original Reci laser tube , Best brand in china )
Using life :8000-10000 hours
Global Warranty 12 months
6. Bracket of co2 laser tube
We not only use the best brand laser tube, in order to make the laser tube to play the best results ,for the auxiliary components ,we have also made constantly improvements, such as laser tube bracket, lens bracket, etc.
7. Laser supplier matched with the laser tube
Laser power supplier installed Independent , compared with the general install together with other Electrical Equipment, it can reduce interference of other
Electrical Equipment this can ensure the better performance of the laser power.
8. 550W exhaust fan
9. Water pump or Water chiller CW3000/5000/5200
To Cool Laser tube and Longer the lifetime of Laser tube.
Supporting upgradation to CW6000 with extra payment.


laser cutter

laser cutting machine

Package:
Every machine is packed with great care and tough material.
It is packed with cling films first and then film bags.
At last, it is packed with wooden case which is reinforced with the iron bar on the top and bottom.
With this kind machine, all our laser machine can protect well during long trip by sea or by train.
We can transport machine by boat or by training, according to your requirement.


laser machine for engraving glass

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Model UTECH Laser cutting machine
Working area 1300*900mm/1300mmx2500mm, etc
Laser Types Seal CO2 LaserTube
Laser power 130W/150W/180W/260W
Engraving speed 100-600mm/s
Cutting speed 0-30mm/s
Location precision ≤0.01mm
Resetting positioning accuracy 0.01mm
Power supply AC110- 220V/50-60HZ
Controlling software RDCAM
Operating temperature 0 - 45°
Operating humidity 5-95%
Minimum shaping character English 1 x 1mm
360°slope engrave Yes
Driving system Stepper
Cooling mode Water-cooling and protection system
Auxiliary Devices Exhauster and the Exhaust Pipe
Software RDCAM V6.0
Graphic format supported BMP, CIF, JPEG, TGA, TIFF, PLT, AI, DXF, DWG,etc
Optional Atuomatic feeding system, rotary axis, auto-focus

Laser Cutting Machine,Laser Cutter,Mini Laser Cutting Machine,Co2 Laser Cutting Machine

Shandong U-May CNC Technology Co., Ltd. , https://www.sesamecnc.com