保险丝介绍 - Fuse Technology.ppt

1、Fuse Technology,Present: Kinrex Corp. - WICKMANN By: Chin Huang,1. Basic Theory of Fuse,a) Circuit Protection Current (Ampere) b) Completed & Perfect Protection It protection, short circuit protection & overloading c) UL 248 & IEC60127 Standards 1A (IEC) = 1.35A 1.4A (UL) d) F (quick-acting) & T (Ti

2、me-lag) F not mean fast blow (lower It) T not mean slow blow (higher It),Overloading Protection,a) UL 248 (mainly 0 30A) F - (Irat x 1) 4 H (Irat x 1.35) 12 S (Irat x 5.0) 10 S,b) IEC60127 (250V & test at 70 2) 5*20 mm high breaking (ceramic tube) Irat x 1 2.1 2.75 4 10 F (0.056.3A) 1H 1H 1H 1H 1H 1

3、H 1H 2 min 400ms10S 150ms3S 20150ms,2. Application Guideline,a) Inrush Current Initial Power on stage FF - short circuit protection esp for semiconductor F - short circuit protection M - quickly decreasing inrush currents with low volt drop T - slowly decreasing inrush current TT - slowly decreasing

4、 inrush current (esp for telecom) b) Impulse Quantity of Pulse Life Time (Power on/off) It of fuse / It of pulse = Fp 3 - 5,000 4 - 50,000 4.5 - 100,000 5 500,000 Impulses,c) Amperage Selection I operating max. * Fi * F Inrush/40 * Fi * F Inrush * (5*tp/pulse shape) * Fi 2 for time-lag fuses with 10

5、,000 pulses 5 for time-lag fuses with unlimited of pulses 36 for quick-acting fuses with unlimited of pulses Pulse shape 1 = rectangular pulse 2 = half sin curve pulse 3 = triangular pulse,3. Protection,a) ampere protection Primary & 2nd protection b) voltage will be considered when fuse melted (bac

6、k arcing) c) Insulation resistance Vrat x 2 Related to the varistor specification IEC 0.1 M PSE/JET 0.2 M UL no arc-back 30s after blowing d) Thermal Fuse Main concern is Temperature not Ampere,4. Fuse Process,a) Element (wire) Copper & Silver round, flat (high ampere) tinned & not tinned diagonal,

7、straight, ball blob & wind b) Element soldering c) Encap d) with pigtails (caps),5. Failure Mode Analysis,a) high current with high back voltage b) high current with low back voltage c) low current with high back voltage d) low current with low back voltage e) current meets voltage on element and causes arcing,6. Reliability & Life Test,a) Cold Resistance (Irat x 0.1) b) Voltage Drop (Irat x 1.0) c) Power Dissipation (UL Irat x 1 / IEC Irat x 1.5) d) Based on Irat x 1.5/2.1/2