POLYFUSEPOLYFUSEA RESETTABLE FUSE

-PRESENTED BY -PRESENTED BYKUSHAL AGARWALEN

OVERCURRENT OVERCURRENT PROBLEMS PROBLEMS

PPTC FUSEPPTC FUSE

qPolymeric Positive Temperature Coefficient Device

qBasically a THERMISTORqA Series Element In A CircuitqSelf Resettable

FUNCTIONS OF PPTCFUNCTIONS OF PPTC

ØOVERCURRENT PROTECTION

ØAUTOMATIC RESTORATION

CONSTRUCTION & OPERATIONCONSTRUCTION & OPERATION

OPERATING PARAMETERSOPERATING PARAMETERS

q INITIAL

RESISTANCE

qOPERATING

VOLTAGE

qHOLDING

CURRENT

qTRIP CURRENT

qTIME TO TRIP

qLEAKAGE

CURRENT

qTRIP CYCLE

qTRIP ENDURANCE

qTHERMAL

DURATION

qHYSTERESIS

OPERATING CURVESOPERATING CURVES

OPERATINGCURVE

OPERATINGCHARACTERISTICS

ADVANTAGES OVER OTHER ADVANTAGES OVER OTHER FUSESFUSES

PPTC CPTC Bi-metal Conventional

Resettable Yes Yes Yes No

Size Small Medium Large Large

Resistance Low High Low Low

Power loss Low High Low Low

Cost Low Medium High High

APPLICATIONSAPPLICATIONS

qBATTERY PROTECTION

qI C PROTECTION

qPROTECTION OF

ELECTRICAL EQUIPMENTS

qPROTECTION DEVICE

INSIDE CONSUMER

ELECTRONICS

qPROTECTION OF

COMPUTER PERIPHERALS

q

POLYFUSE

CONCLUSIONCONCLUSION

üSELF RESETTABLE DEVICE

üCOMPACT

üLOW RESISTANCE

üIDEAL FOR LOW VOLTAGE A.C. & D.C.

REFERENCESREFERENCES

• Electronics For You, Edition- September, 2004

• Raychem circuit protection products- Tyco Electronics

• http://www.circuitprotection.com • http://www.wikipedia.com• http://www.inter-technical.com

QUERIES???