WRE-130 WRE-131 WRE-132 WRE-133 WRE-123 assembly thermocouple, fully sealed film variable resistors are also called solid variable resistors. The resistor body is made of carbon black, quartz powder, organic binder and other materials, and then pressed into the base of plastic or epoxy resin. , And then heated and polymerized. The movable contacts use carbon contacts and the adjustment parts are made of plastic. The resistor body and the movable contact are sealed by a metal casing (there is an adjustment hole above the metal casing). Its advantage is that it has good dustproof performance and rarely has bad contact failure.
The manufacturing process of the resistor body of the semi-sealed film variable resistor is basically the same as that of the fully sealed variable resistor body. The movable contact piece adopts a metal reed, and the outer plastic cover is sealed. When the plastic cover is rotated, the movable contact piece also rotates with it. This variable resistor is easy to adjust, but its dust resistance is not as good as a fully sealed film type variable resistor.
Non-sealed film variable resistors are also called chip adjustable resistors. The resistor body is made of carbon black, graphite, quartz powder, organic binder, etc. to form a suspension, which is coated on glass fiber board or bakelite. Into. The movable contact piece uses a metal reed, and the reed has an adjustment hole, and no separate adjustment component is provided. Its disadvantages are poor dust-proof performance, the contacts are susceptible to oxidation, and prone to failure due to poor contact with the synthetic carbon film.