{1269} PolySwitch Resettable PPTC Fuse скачать в хорошем качестве

{1269} PolySwitch Resettable PPTC Fuse

In this video number {1269} PolySwitch Resettable PPTC Fuse. I explained what is PolySwitch Resettable PPTC Fuse. Resettable fuse or polymeric positive temperature coefficient device (PPTC) is a passive electronic component, used to protect against over-current faults in electronic circuits. It is also named as a multifuse or polyfuse or polyswitch. Its function is similar to PTC thermistors in certain situations. These are made by non-conductive crystalline organic polymer matrix that is loaded with carbon black particles to make it conductive. While cold it allows to flow rated current . If current exceeds than its rated vlaues, it begins to heat. As the device heats up, the polymer will expand, changing from a crystalline into an amorphous state. The expansion separates the carbon particles and breaks the conductive pathways, causing the device to heat faster and expand more, further raising the resistance. This increase in resistance substantially reduces the current in the circuit. A small (leakage) current still flows through the device and is sufficient to maintain the temperature at a level which will keep it in the high resistance state. Leakage current can range from less than a hundred mA at rated voltage up to a few hundred mA at lower voltages. The device can be said to have latching functionality. The hold current is the maximum current at which the device is guaranteed not to trip. The trip current is the current at which the device is guaranteed to trip. When power is removed, the heating due to the leakage current will stop and the PPTC device will cool. As the device cools, it regains its original crystalline structure and returns to a low resistance state where it can hold the current as specified for the device. This cooling usually takes a few seconds, though a tripped device will retain a slightly higher resistance for hours, unless the power in it is weaker, or has been often used, slowly approaching the initial resistance value. The resetting will often not take place even if the fault alone has been removed with the power still flowing as the operating current may be above the holding current of the PPTC. The device may not return to its original resistance value; it will most likely stabilize at a significantly higher resistance (up to 4 times initial value). It could take hours, days, weeks or even years for the device to return to a resistance value similar to its original value, if at all protection for applications where space is at a premium and resettable protection is desired. You are Invited to Join Haseeb Electronics    / @haseebelectronics   You can Follow me on :- Instagram:   / haseebelect   Facebook: https://web.facebook.com/profile.php?... Please check other videos :- Replacing Heating Element in WELLER DSX80 Desoldering Gun    • {1213} Replacing Heating Element in WELLER...   Vestel Power supply working and troubleshooting    • {1216} Vestel Power supply working and tro...   Electric steam iron repair    • {1218} Please Write your opinion for this ...   Reverse polarity & Overvoltage effect on Polarized capacitor    • {1207} Reverse polarity & Overvoltage effe...   SMD zener diode Identification    • {1210} SMD zener diode Identification   measure Low value resistor Using NULL / RELATIVE function    • {1217} Use NULL / REL function to measure ...   Reverse polarity & Overvoltage effect on Polarized capacitor    • {1207} Reverse polarity & Overvoltage effe...   Electric Room heater fan repair - not providing hot air    • {1202} Room heater fan not providing hot air   Testing Darlington transistor    • {1195} Testing 2N6283 Darlington transistor   Inercomp PT300 Truck weight scale repair    • {1186} Truck weight scale repair   You can Follow me on :- Instagram:   / haseebelect   Facebook: https://web.facebook.com/profile.php?... #pptc #resettablefuse #electronics