• Inrush Current Limiting Power NTC Thermistors For Switch Mode Power Supply
Inrush Current Limiting Power NTC Thermistors For Switch Mode Power Supply

Inrush Current Limiting Power NTC Thermistors For Switch Mode Power Supply

Product Details:

Place of Origin: Dongguan,Guangdong,China
Brand Name: UCHI
Certification: UL.VDE.SGS.
Model Number: MF72

Payment & Shipping Terms:

Minimum Order Quantity: 5000PCS
Price: Negotiable
Packaging Details: Bulk/Ammo/Reel
Delivery Time: 3~5 working days
Payment Terms: T/T,Paypal,Western Union,Money gram
Supply Ability: 8000,000,000PCS Per Month
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Detail Information

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power ntc thermistor

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ntc thermistor assembly

Product Description

Inrush Current Limiting Power NTC Thermistors For Switch Mode Power Supply

 

Quick Detail:

 

·Low cost solid state device for inrush current supression.
·Minimise line current distortion and radio noise.
·Protect switches, rectifier diodes and smoothing capacitors against premature failures. 
·Prevent fuse from blowing in error.

 

 

Description:

 

Power NTC thermistor can be a cost effective device to limit the amount of inrush current in a switching power supply or other devices when the power is first turned on. Power NTC thermistor limits surge current by functioning as a power resistor which drops from a high cold resistance to a low hot resistance when heated by the current flowing through it. 
Inrush-current limiters power NTC thermistor protect circuits from undesirably high currents, suppressing high inrush current surges, while its resistance remains negligible low during continuous operation. Thanks to their low resistance in the operating state, Power thermistor have a considerably lower power dissipation than the fixed resistors frequently used for this application.

 

 

Applications:

 

Limiting surge current, suitable for the protection of switch mode power supply, UPS power, transformers, motors, various electric heating utensil, energy saving lights, ballast, various power circuit, amplifiers, colored displayer, monitors, color TV, filament protection, etc.
Power thermistor components can also be used for the soft starting of motors, for example in vacuum cleaners with continuous currents of up to 20 A.

 

 

Specifications:

 

 

Inrush Current Limiting Power NTC Thermistor Features:

·Resin coated disk thermistor with uninsulated lead-wires.
·Suitable for both AC and DC circuits up to a voltage of 265 V(rms). 
·Wide range of resistance, current and dimension. 
·Excellent mechanical strength. 
·Suitable for PCB mounting.

 

 

Comparison curve with and without Inrush Current Limiting Power NTC thermistor application

Comparison curve with and without Inrush Current Limiting power NTC thermistor

Inrush Current Limiting Power NTC thermistor Load-temperature characteristics

Inrush Current Limiting Power NTC thermistor 
Load-temperature characteristics
Typical Application of Inrush Current Limiting Power NTC thermistors for Circuit Protection

Basic circuit diagram NTC thermistor for diode protection

Basic circuit diagram NTC thermistor for diode protection

NTC Thermistor for inrush current protection circuit

 

Possible locations of NTC Thermistors inrush current limiters

Typical power supply circuit

 

Typical power supply circuit

Power thermistor application circuits

 

Power NTC thermistors application circuits

Inrush Current Limiting Power NTC thermistor for Circuit Protection application

 

Another example NTC Thermistor for inrush current protection circuit

Inrush Current Limiting Power NTC Thermistors For Switch Mode Power Supply 7

 

Inrush Current Limiting Power NTC Thermistors Dimensions (mm)

Inrush Current Limiting Power NTC Thermistor Outlook

Inrush Current Limiting Power NTC Thermistors Data Sheet

 

 

Part No.

R25 
(ohm)

Max 
Stable 
Current
(A)

Approx.
Resistance 
value at
max current
(Ω)

Dissipation 
Factor 
(mW/oC)

Thermal 
Time 
Constant 
(sec)

Dimensions (mm)

Dmax

Tmax

H

H 0

d±1

MF72-3D9

3 ohm

4A

0.120

11

34

11

5.5

13.5

20.5

7.5 /5

MF72-5D9

5 ohm

3A

0.210

11

34

11

5.5

13.5

20.5

7.5 /5

MF72-8D9

8 ohm

2A

0.400

11

32

11

5.5

13.5

20.5

7.5 /5

MF72-10D9

10 ohm

2A

0.458

11

32

11

5.5

13.5

20.5

7.5 /5

MF72-16D9

16 ohm

1A

0.802

11

31

11

5.5

13.5

20.5

7.5 /5

MF72-22D9

22 ohm

1A

0.950

11

30

11

5.5

13.5

20.5

7.5 /5

MF72-33D9

33 ohm

1A

1.124

11

30

11

5.5

13.5

20.5

7.5 /5

MF72-50D9

50 ohm

1A

1.252

11

30

11

5.5

13.5

20.5

7.5 /5

MF72-80D9

80 ohm

0.8A

2.010

11

30

11

5.5

13.5

20.5

7.5 /5

MF72-3D11

3 ohm

5A

0.100

13

43

13

5.5

15.5

22.5

7.5 /5

MF72-5D11

5 ohm

4A

0.156

13

45

13

5.5

15.5

22.5

7.5 /5

MF72-8D11

8 ohm

3A

0.255

14

47

13

5.5

15.5

22.5

7.5 /5

MF72-10D11

10 ohm

3A

0.275

14

47

13

5.5

15.5

22.5

7.5 /5

MF72-12D11

12 ohm

2A

0.462

14

48

13

5.5

15.5

22.5

7.5 /5

MF72-16D11

16 ohm

2A

0.470

14

50

13

5.5

15.5

22.5

7.5 /5

MF72-20D11

20 ohm

2A

0.512

15

52

13

5.5

15.5

22.5

7.5 /5

MF72-22D11

22 ohm

2A

0.563

15

52

13

5.5

15.5

22.5

7.5 /5

MF72-33D11

33 ohm

1.5A

0.734

15

52

13

5.5

15.5

22.5

7.5 /5

MF72-50D11

50 ohm

1.5A

1.021

15

52

13

5.5

15.5

22.5

7.5 /5

MF72-60D11

60 ohm

1.5A

1.215

15

52

13

5.5

15.5

22.5

7.5 /5

MF72-1.3D13

1.3 ohm

7A

0.062

13

60

15.5

6

17.5

24.5

7.5

MF72-3D13

3 ohm

6A

0.092

14

60

15.5

6

17.5

24.5

7.5

MF72-5D13

5 ohm

5A

0.125

15

68

15.5

6

17.5

24.5

7.5

MF72-10D13

10 ohm

4A

0.206

15

65

15.5

6

17.5

24.5

7.5

MF72-15D13

15 ohm

3A

0.335

16

60

15.5

6

17.5

24.5

7.5

MF72-30D13

30 ohm

2.5A

0.517

16

65

15.5

6

17.5

24.5

7.5

MF72-47D13

47 ohm

2A

0.810

17

65

15.5

6

17.5

24.5

7.5

MF72-1.3D15

1.3 ohm

8A

0.048

18

68

17.5

6

19.5

26.5

10/7.5

MF72-1.5D15

1.5 ohm

8A

0.052

18

69

17.5

6

19.5

26.5

10/7.5

MF72-3D15

3 ohm

7A

0.075

18

76

17.5

6

19.5

26.5

10/7.5

MF72-5D15

5 ohm

6A

0.112

20

76

17.5

6

19.5

26.5

10/7.5

MF72-8D15

8 ohm

5A

0.178

20

80

17.5

6

19.5

26.5

10/7.5

MF72-10D15

10 ohm

5A

0.180

21

85

17.5

6

19.5

26.5

10/7.5

MF72-15D15

15 ohm

4A

0.268

20

75

17.5

6

19.5

26.5

10/7.5

MF72-30D15

30 ohm

3.5A

0.438

18

75

17.5

6

19.5

26.5

10/7.5

MF72-47D15

47 ohm

3A

0.680

21

86

17.5

6

19.5

26.5

10/7.5

MF72-0.7D20

0.7 ohm

12A

0.018

25

89

22.5

7

24.5

31.5

10/7.5

MF72-1.3D20

1.3 ohm

9A

0.037

24

88

22.5

7

24.5

31.5

10/7.5

MF72-3D20

3 ohm

8A

0.055

24

88

22.5

7

24.5

31.5

10/7.5

MF72-5D20

5 ohm

7A

0.087

23

87

22.5

7

24.5

31.5

10/7.5

MF72-8D20

8 ohm

6A

0.142

25

105

22.5

7

24.5

31.5

10/7.5

MF72-10D20

10 ohm

6A

0.162

24

102

22.5

7

24.5

31.5

10/7.5

newly developed inrush current limiting power NTC thermistor increased max. operating current.

Part No.

R25

(ohm)

Max Stable Current

(A)

Approx.

Resistance

Value at

Maximum Current (Ω)

Max Rated Power Pmax.

(W)

Dissipation Factor

(mW/oC)

Thermal Time Constant (s)

Dimensions (mm)

Dmax

Tmax

H

H 0

d

Pin

form

D15mm

2.5ohm/9.5A

2.5 ohm

9.5A

0.044

3.5W

22 min

75 max

17.5

6

19.5

26.5

7.5

inner kinked

D15mm

5 ohm/8A

5 ohm

8A

0.058

3.5W

22 min

75 max

17.5

6

19.5

26.5

7.5

inner kinked

D15mm,

10 ohm/7A

10 ohm

7A

0.098

3.5W

22 min

75 max

17.5

6

19.5

26.5

7.5

inner kinked

D20mm

1 ohm/16A

1 ohm

16A

0.027

5W

28 min

110 max

22.5

7

24.7

/

10

straight

D20mm

5 ohm/12A

5 ohm

12A

0.047

5W

28 min

110 max

22.5

7

24.7

/

10

straight

D20mm,

10 ohm/8A

10 ohm

8A

0.085

5W

28 min

110 max

22.5

7

24.7

/

10

straight

D25mm,

1 ohm/20A

1 ohm

20A

0.021

7W

30 min

130 max

29

8

33

/

10

straight

D25mm

, 5 ohm/14A

5 ohm

14A

0.047

7W

30 min

130 max

29

8

33

/

10

straight

D25mm,

10 ohm/10A

10 ohm

10A

0.084

7W

30 min

130 max

29

8

33

/

10

straight

D30mm,

1 ohm/30A

1ohm

30A

0.014

8W

40 min

190 max

36

8.5

40

/

18

straight

D30mm,

10 ohm/13A

10 ohm

13A

0.056

8W

40 min

190 max

36

8.5

40

/

18

straight

Inrush Current Limiting Power NTC thermistor Reliability Data
Test
Standard
Test Conditions
ΔR25/R25 (typical)
Remarks

Storage in dry heat

IEC 60068-2-2

Storage at upper category temperature Temperature: 125oC Time: 1000h

<10%

No visible damage

Storage in damp heat, steady state

IEC 60068-2-3

Temperature of air: 40oC Relative humidity of air: 93% Duration: 21 days

<5%

No visible damage

Rapid temperature cycling

IEC 60068-2-14

Lower test temperature: -55oC Upper test temperature: 125oC Number of cycles: 10

<10%

No visible damage

Endurance

 

I=Imax t: 1000h

<10%

No visible damage

Cyclic endurance

 

I=Imax, 1000 cycles On-time=1 min Cooling time=6 min

<10%

 

Transient load

 

Capacitance=CT Number of cycles: 1000

<5%

No visible damage

Reference information for selecting inrush current limiting power NTC thermistor

1) Maximum operating current > Actual operating current in the power loop
2) Rated zero power resistance at 25C
<img data-cke-saved-src="http://www.amwei.com/pima/Resistance%20calculation.gif" src="http://www.amwei.com/pima/Resistance%20calculation.gif" "alt="Resistance calculation"> 
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 operating current
3) The larger Beta value, the smaller residual resistance, the smaller operating temperature rising.
4) Generally, the larger product of time constant and dissipation coefficient, the larger NTC thermal capacity, the more powerful NTC thermistor surge current restraining capacity.

 

 

Inrush Current Limiting Power NTC Thermistor Application Precautions

1) For inrush current limiting, the NTC thermistor must be connected in series with the load circuit. Several inrush current limiters can also be connected in series for higher damping. Inrush current limiters must not be connected in parallel.
2) In general inrush current limiters require time to get back to cold state, in which they can provide adequate inrush current limiting due to their high resistance. The cooling down time depends on ambient conditions.
3) It should be considered that the surrounding area of NTC Thermistor may become quite hot.Ensure the adjacent components are placed at sufficient distance from a thermistor to allow for proper cooling time of the thermistor.
4) Make sure that adjacent materials are designed for operation at temperatures comparable to the surface temperature of the thermistor. Make sure that surrounding parts and materials can withstand this temperature.
5) Make sure that thermistors are adequately ventilated to avoid overheating.
6) Avoid comtamination of the thermistor surface. 
7) Avoid contact of NTC thermistors with any liquids and solvents. Ensure that no water enters an NTC thermistor. 

 

 

Competitive Advantage:

 

  1. Factory supply directly

  2. Completed certificates such as UL,VDE,SGS,etc and high quality available

  3.  Quick delivery

  4. Best after-sales services

  5. OEM & ODM available

Inrush Current Limiting Power NTC Thermistors For Switch Mode Power Supply 9

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