|
 (MF72)Thermistors |
·Introduction:
Power type thermistor is the semiconductor ceramic components manufactured mainly by transition metal oxide, belonging to the negative temperature coefficient thermistor. When current is added directly to the power type NTC thermister, its resistance will decrease rapidly with the heating of resistor. As the power type NTC thermistor has a rated zero-power resistance, it can effectively inhibit the surge current upon startup when it is connected in series in the circuit. After it inhibits the surge current, due to the continuous effect of the current passing through it, the resistance of power type NTC thermistor will decrease to a very small degree. As its dissipation power can be neglected, it will not cause very large impact to the normal operating current.
·Application:
It is used for inhibiting the surge current of converted power supply, UPS power supply and other equipments.
It is used for inhibiting the surge current of CRT, LCD, power of various electronic devices, and color kinescope.
It is used for controlling the current of motor, various heaters, bulb voltage stabilizer, electronic energy-saving lamp, electronic rectifier and other electronic installations.
·Features:
Safe, reliable, stable, with wide range of over-current control
Small size, large power, with strong capacity to inhibit surge current
Large material constant (B value), with small residual resistance
Thermal shock resistance, with wide range of operating temperature
·Selection principle of power type NTC thermistors:
Max. working current of resistor ＞ working current of actual loop
Nominal resistance of power type NTC resistor:
For converted power supply, inverted power supply, switch power supply and UPS power supply, Im shall be 100 times of working current.
For reheater loop, Im is taken 30 times of working current. When B value is larger, residual resistance is smaller, and the temperature rising during operation is smaller.
·Sign description:
·Structure dimension :
|
Specification |
Dimension（mm） |
|
Dmax |
Lmax |
C± 1 |
Tmax |
d±0.5 |
|
Φ 5 |
6.5 |
31 |
5 |
4 |
0.55 |
|
Φ 7 |
8.0 |
31 |
5 |
4 |
0.55 |
|
Φ 8 |
9.0 |
31 |
5 |
5 |
0.7 |
|
Φ 9 |
10 |
31 |
7.5 |
5 |
0.7 |
|
Φ 10 |
11 |
31 |
7.5 |
5 |
0.8 |
|
Φ 11 |
12 |
31 |
7.5 |
5 |
0.8 |
|
Φ 13 |
14.5 |
30 |
7.5 |
6 |
0.8 |
|
Φ 15 |
16.4 |
30 |
7.5 |
6 |
1.0 |
|
Φ 20 |
22 |
29 |
7.5/10 |
7 |
1.0 |
Note: X is determined according to user’s requirements
·Power type NTC thermistors product list IN Data Download |
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