MF-VS170SS-0 application field and working principle

PTC resettable fuse is a current-limiting protective device applied in electronic circuits, especially in the secondary side of electronic transformer for household appliances. In the market, this kind of fuse is mainly represented by Polymeric Positive Temperature Coefficient Resettable Fuse (PPTC) and Resettable Fuse (RTF). The MF-VS170SS-0is a representative and popular product in the MF series PTC resettable fuses.

MF-VS170SS-0 is specifically designed to protect the secondary side of electronic transformer from any unexpected over-current. It can limit the over-current automatically within the whole range of 0.1A~17A, and will shut off automatically once the over-current detected. The unique electronic construction of MFS170SS-0 enables it to reset the circuit automatically when the current drops back to normal.

FF-V170SS-0 is based on the switching-off principle. When the current rises higher than the max current (Ihold)value which is defined as the max current the fuse can sustain, the melting alloy wire (or bimetal) inside the PTC resettable fuse is set off, and then fuses off to achieve the protection purpose. Then the circuit enter the standby state. When the PTC fuse is set off, the circuit isolated and the VCO element is put into action, and then activates the RD element, to further force the circuit to enter the standby state for safety.

In order to reset the fuse, the current needs to be brought back to normal level (Itrip level). The Itrip value of MF-VS170SS-0 is more or less 10%-20%of IHold value. Once the current reach back to the noraml operational value, the RD element will be switched off and then RD element release the resordonce to control to VCO element to reset the PTC element. The process of resetting is usually less than 2 seconds.

Advantages

Compared to traditional fuses, PTC resettable fuse MF-VS170SS-0 has the following advantages:

• Easy to be reset: The most obvious advantage of PTC resettable fuses is that it can reset automatically when the current back to the original level. This allows us to avoid any unnecessary shutdown of the device.
• Lower cold resistance: The cold resistance of MF-VS170SS-0 is really low, merely 0.3mΩ, less than half of traditional 0.5A-6A fuse.
• Large current setting range: The current setting range of MF-VS170SS-0 extends from 0.1A to 17A, which enable it to fit into a wide range of applications.
• Strong overload protection: The current limiting protection of MF-VS170SS-0 can prevent the system from any damage by over-currents.

Conclusion

In short, MF-VS170SS-0 PTC Resettable Fuse has a wide range of applications in the secondary side of electronic transformer and an extensive set of advantages. The fuse can effectively protect the circuit from any over-current, and provide a stable output power. The current setting range and cold resistance make it suitable for a variety of electronic products. All of these, makes MF-VS170SS-0 a really competitive product in the field of PTC resettable fuses.