NTC Thermistor Inrush Current limiter MF72

Introduction to NTC Thermistor Inrush Current limiter MF72

The NTC Thermistor MF72 series Power Type Thermistor Inrush Current limiter are specifically designed for surge suppression, offering reliable protection for electronic equipment. This NTC Thermistors for Inrush Current Limiting are made from specially formulated metal oxide ceramic materials. 

This NTC Thermistor is radial resin-coated and effectively limits high surge currents. Integrating an MF72 into the power supply loop is a straightforward and efficient method to mitigate switch-on surge currents, thereby protecting sensitive electronic equipment.

Applications of NTC Thermistor MF72 for Inrush Current Limiting

Versatile Use of NTC Thermistor Inrush Current Limiter

• Power Supplies:NTC Thermistors for Inrush Current Limiting are widely used in conversion power supplies, switch-mode power supplies, and UPS systems to prevent overcurrent issues..
• Electronic Circuits: This NTC thermistor ensures stable operation in power supply circuits, making them vital for various electronic equipment.
• Heating Elements: The MF72 thermistor is commonly found in electric heaters, offering protection against surges in thermal heating applications.
• Electronic ballasts and Lighting: Thermistor Inrush Current limiter protects Electronic ballasts, filaments in bulbs, electronic energy-saving lamps,and other lighting equipment.
• Display and Oscillation Systems: In display units, the NTC Thermistor ensures reliable operation, safeguarding against power surges.

• Application Example of MF72 NTC Thermistors for Inrush Current Limiting

   

  

Advantages of Using NTC Thermistor MF72

1. 1.Extended Service Life: Thermistor Inrush Current limiter designed for longevity and reliability in various applications.
2. 2.Compact size: Small size with substantial power surge handling capabilities
3. 3.Rapid response:NTC Thermistors for Inrush Current Limiting fast response to surge currents
4. 4.Strong Surge Protection: Effectively limits inrush current, preventing potential damage to circuits.
5. 5.High Efficiency: High material constant (Thermistor B Value) and low residual resistance
6. 6.Wide Range of Electrical Characteristics: Customizable to meet diverse application needs.
7. 7.Minimal Power Consumption: Minimal power loss during steady-state operation (typically 1W or less).
8. 8.Superior Reliability: Excellent thermal and electrical reliability.
9. 9.Diverse Electrical Options: Wide selection of electrical characteristics
10. 10.Wide Temperature Range: MF72 with wide operating temperature -55~+200 ℃.
11. 11.RoHS compliant

12. Comparison without and with MF72 Thermistor Inrush Current limiter

    

     

Main Features of MF72 NTC Thermistors for Inrush Current Limiting

NTC Thermistor Main Technical Parameters

Dimensions of NTC Thermistors for Inrush Current Limiting

The dimensions and appearance of the MF72 series thermistors are as follows:

(Unit: mm):

Selection Guide of NTC Thermistor MF72

When selecting an NTC thermistors for surge suppression, consider the following:

1. Maximum operating current > Actual operating current in the power loop
2. Rated zero power resistance at 25C of which,

E: loop voltage, Im: Surge current
For conversion power, reversion power, switch power, UPS power, Im=100 times operating current
For filament, heater, Im =30 times the operating current

Working Principle of Thermistor Inrush Current limiter

NTC Thermistors for Inrush Current Limiting

When turning on electrical equipment, a significant surge current occurs immediately. This surge can be effectively restrained by using a power MF72 NTC thermistor connected in series with the power circuit, which may include components like capacitors, heaters, or motors. This inrush current lasts short, but its peak current is prodigious. It can even exceed 100 times of operating current in conversion power, switch power and UPS power.

Importance of NTC Thermistor for Limiting Surge Current

To effectively manage this surge current, an NTC thermistor is crucial. When current is applied to the thermistor, its resistance decreases rapidly as it heats up.A power-type MF72 thermistor has a specified zero power resistance. When placed in series with the circuit, it effectively restrains the switch-on surge current. Once the surge current limiting function is completed, the thermistor's resistance drops to a negligible level, allowing normal operation without significant power consumption.

Benefits of Thermistor Inrush Current limiter

Applying a power NTC thermistor in the power supply loop is a most effectively and most brief measure to restrain surge current,protecting electrical equipment from destruction.Be noticed, the NTC Thermistors for Inrush Current Limiting can not be used in parallel in the circuit since one unit will tend to conduct all the current available nearly.Therefore,thermistor may be used in the AC(position A1 or A2) or the DC(position D1 or D2) locations in the circuit(see Fig A).

Part Number Marking of MF72 NTC Thermistor 

MF72	-----	10	D	11
1		2	3	4

• 1.Series: MF72 - NTC Thermistor for surge suppression
• 2.R25 Resistance: 10-10Ω
• 3.Dimension:D-Diameter of the Thermistor Inrush Current limiter
• 4.Chip Diameter: 11-Φ11mm

Model List of NTC Thermistors for Inrush Current Limiting

• MF72 D5 Series
• MF72 D8 Series
• MF72 D10 Series
• MF72 D13 Series
• MF72 D15 Series
• MF72 D20 Series
• Etc.
  Product Coating color: black or green

MF72 NTC Thermistor Specifications and Part No.:

Expore the Specifications and Part No. of Power NTC thermistors for limmiting surge current at the bottom of this page.

Note：
1.Unless particular indication,the allowable tolerance of the R25 Resistance is ±20%
2.Encapsulation mode can be made per customer’s requirement.
3.Wire shape kinked form can be selected.
4.Can be custom-made per customer's requirement.

a. S shows straight lead wire;
b. 17/5:17 shows the long bend lead wire; 5 shows the short bend lead wire.

User Reviews and Summary of MF72 NTC thermistor

User Reviews of Thermistor Inrush Current limiter

Users consistently commend the MF72 series NTC Thermistor for its reliability and effectiveness in protecting electronic circuits from surge currents. The MF72 Thermistor's fast response time and minimal power consumption are often highlighted as key benefits.

Summary of NTC Thermistors for Inrush Current Limiting

The MF72 series NTC Thermistor is an excellent choice for applications requiring robust surge suppression. Its combination of high reliability, wide operational range, and efficient performance makes it a valuable component in safeguarding electronic devices and circuits.