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Notes on the use of relays

2020-01-10
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1.Transportation and installation
The relay is a precision machine, so it is more sensitive to abusive transportation methods. Many methods have been adopted in the manufacturing process to ensure that the relay is well protected during transportation. Therefore, during the inspection of the factory and the users subsequent installation, do not damage The initial performance of the relay should also pay attention to the following points: In order to prevent the terminal surface from being contaminated, the terminal should not be directly contacted, otherwise the solderability may be reduced. The position of the lead-out end should match the hole position of the printed board. Improper cooperation may cause dangerous stress to the relay and damage its performance. Please refer to the punching diagram in the sample to punch holes. Care should be taken to monitor storage temperature and to avoid relay storage for as long as possible (recommended not to exceed three months). The relay should be stored and installed in a clean environment.

2.Flux coating
Unplasticized relays are susceptible to flux contamination. It is recommended to use solder-resistant or plastic-sealed relays to prevent the intrusion of flux gas from the terminal and the gap between the base and the housing. This type of relay is suitable for multi-bubble flux or spray flux processes. If the anti-flux type relay adopts preheating and drying, it can further prevent the intrusion of the flux.

3. Welding process
When using flux or automatic welding, care should be taken not to damage the relay performance. Flux-resistant relays or plastic-sealed relays can be suitable for dip soldering or wave soldering processes, but the maximum soldering temperature and time should be controlled according to the selected relay.

4.Cleaning process
The overall cleaning of non-plastic-sealed relays should be avoided. The plastic-sealed relays should be cleaned with an appropriate cleaning agent. Freon or alcohol is recommended. Ultrasonic cleaning should be avoided as much as possible because the harmonics of the ultrasonic frequency will cause contact friction Welding (cold welding) and may cause the contacts to jam. After cleaning and drying, ventilate immediately to reduce the relay to room temperature.

5.Installation direction
The correct installation direction is important to achieve better relay performance.
1) The ideal installation direction for impact resistance is to make the contact and movable parts (armature part) perpendicular to the vibration or impact direction with the moving direction. When the normally open contact is not excited, its vibration and impact resistance is largely Affected by the relay installation direction.
2) The installation direction of the contact reliability relay should be such that the contact surface is vertical to prevent pollution and dust from falling on the contact surface, and it is not suitable to switch large loads and low-level loads on one relay at the same time, otherwise it will affect each other .
3) Adjacent installation When many relays are required to be installed next to each other, due to the superposition of the generated heat, abnormal high temperatures may be caused. Therefore, there should be sufficient clearance between each other (typically> 5mm) to prevent Heat buildup. In any case, make sure that the ambient temperature of the relay does not exceed the sample specification.
4) Use of sockets When using sockets, ensure that the sockets are installed securely, that the relay pins are in reliable contact with the sockets, that the mounting holes and sockets are well matched, and that the sockets and relay mounting brackets are used properly.
5) Selection of connecting leads. If you need to connect the relay with a lead wire, you should select a lead wire with an appropriate cross-sectional area according to its load.

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