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Ametherm Ampron Panasonic Alternative Power NTC Thermistor 5 Ohm 40A For Limiting Inrush Current
Overview Of The Power NTC Thermistor 5 Ohm 40A
R25(Ω): 0.2~20 Imax(A): 90A
[Product Features] Large current, long life, high reliability
[Product use] High-power switching power supply, conversion power
supply, UPS power supply
Inrush current is the momentary surge of current created when power
is turned on to motors,transformers,power suppliers and heating
elements. The more power required by industrial equipment,the
larger the inrush current. It can effectively quench the inrush
current by means of in series with power NTC thermistor in return
circuit of power supply. The thermistor’s resistance decreases
dramatically following the inrush,allowing the steady state curent
to flow with very little resistance.This effect provides inrush
current protection, yet allows efficiency during normal
operation.The power NTC Thermistor produced by Dongguan Ampfort
Electronics Co.,Ltd. with large scale,especially
MF73T,MF73,MF74,MF75 serial products with big size,which can be
applied in such inrush protection with industrial level as
industrial robots and automation.
Features Of The Power NTC Thermistor 5 Ohm 40A
● High power, strong ability to suppress inrush current.
● The material constant (B value) is large, the residual resistance is small, and its own power consumption is small.
● Large current, long life, high reliability.
● Easy to install the circuit board, complete series and wide application range.
Application Of The Power NTC Thermistor 5 Ohm 40A
Nuclear magnetic resonance equipment, high-power audio power
amplifier, high-power toroidal transformer.
Solar panel array of high-capacity power inverter.
Industrial robot driven by high voltage power supply.
Dimension Of The Power NTC Thermistor 5 Ohm 40A (mm)
Body size | Φ40 | Φ45 | Φ50 |
Thickness(Tmax) | 46 | 46 | 46 |
Pitch(F±1.5) | 30 | 30 | 30 |
Lead length(L±2) | 40 | 40 | 40 |
Height (Ho max) | 110 | 110 | 110 |
Lead width(W±0.2) | 12 | 12 | 12 |
Lead thickness(H±0.1) | 1.2 | 1.2 | 1.2 |
Body size | Φ40 | Φ45 | Φ50 |
Thickness | 46 | 46 | 46 |
Pitch(F±1.5) | 30 | 30 | 30 |
Lead length(L±2) | 40 | 40 | 40 |
Height (Ho max) | 110 | 110 | 110 |
Lead width(W±0.2) | 12 | 12 | 12 |
Lead thickness(H±0.1) | 1.2 | 1.2 | 1.2 |
Width of low lead(W1±0.2) | 8 | 8 | 8 |
Specificational Data Of The Power NTC Thermistor 5 Ohm 40A
Body diameter Φ40mm
P/N | R25 ±20%(Ω) | Thermal sensitive index B±10%(K) | Max steady state current Imax(A) | Approx R of Max current Rmax(Ω) | Max power dissipation Pmax(W) | Dissipation factor (mW/C) | Thermal time constant (s) | Max impulse capacitance (uF)240VAC |
MF75-0.2/55 | 0.2 | 2600 | 55 | 0.007 | 30 | ≥55 | ≤350 | 8000 |
MF75-0.5/50 | 0.5 | 2600 | 50 | 0.008 | 6800 | |||
MF75-1/45 | 1 | 2600 | 45 | 0.01 | 6800 | |||
MF75-1.5/40 | 1.5 | 2600 | 40 | 0.012 | 6800 | |||
MF75-2/35 | 2 | 2600 | 35 | 0.014 | 6800 | |||
MF75-2.5/33 | 2.5 | 2800 | 33 | 0.018 | 6800 | |||
MF75-3/32 | 3 | 2800 | 32 | 0.02 | 6800 | |||
MF75-4/30 | 4 | 2800 | 30 | 0.022 | 4700 | |||
MF75-4.7/28 | 4.7 | 3000 | 28 | 0.023 | 4700 | |||
MF75-5/27 | 5 | 3000 | 27 | 0.028 | 4700 | |||
MF75-6.8/25 | 6.8 | 3000 | 25 | 0.03 | 4700 | |||
MF75-8/22 | 8 | 3200 | 22 | 0.034 | 3300 | |||
MF75-10/21 | 10 | 3200 | 21 | 0.038 | 3300 | |||
MF75-12/20 | 12 | 3200 | 20 | 0.04 | 3300 | |||
MF75-15/18 | 15 | 3200 | 18 | 0.05 | 3300 | |||
MF75-18/16 | 18 | 3200 | 16 | 0.062 | 3300 | |||
MF75-20/15 | 20 | 3200 | 15 | 0.075 | 3300 |
Body diameter Φ45mm
P/N | R25 ±20%(Ω) | Thermal sensitive index B±10%(K) | Max steady state current Imax(A) | Approx R of Max current Rmax(Ω) | Max power dissipation Pmax(W) | Dissipation factor (mW/C) | Thermal time constant (s) | Max impulse capacitance (uF)240VAC |
MF75-0.2/70 | 0.2 | 2600 | 70 | 0.006 | 45 | ≥70 | ≤480 | 11500 |
MF75-0.5/55 | 0.5 | 2600 | 55 | 0.007 | 8000 | |||
MF75-1/52 | 1 | 2600 | 52 | 0.009 | 8000 | |||
MF75-1.5/50 | 1.5 | 2600 | 50 | 0.011 | 8000 | |||
MF75-2/45 | 2 | 2600 | 45 | 0.012 | 8000 | |||
MF75-2.5/40 | 2.5 | 2800 | 40 | 0.015 | 8000 | |||
MF75-3/38 | 3 | 2800 | 38 | 0.018 | 8000 | |||
MF75-4/36 | 4 | 2800 | 36 | 0.02 | 6800 | |||
MF75-4.7/35 | 4.7 | 3000 | 35 | 0.022 | 6800 | |||
MF75-5/35 | 5 | 3000 | 35 | 0.025 | 6800 | |||
MF75-6.8/32 | 6.8 | 3000 | 32 | 0.028 | 6800 | |||
MF75-8/30 | 8 | 3000 | 30 | 0.03 | 4700 | |||
MF75-10/28 | 10 | 3200 | 28 | 0.032 | 4700 | |||
MF75-12/25 | 12 | 3200 | 25 | 0.034 | 4700 | |||
MF75-15/23 | 15 | 3200 | 23 | 0.042 | 4700 | |||
MF75-18/20 | 18 | 3200 | 20 | 0.061 | 4700 | |||
MF75-20/18 | 20 | 3200 | 18 | 0.07 | 4700 |
Body diameter Φ50mm
P/N | R25 ±20%(Ω) | Thermal sensitive index B±10%(K) | Max steady state current Imax(A) | Approx R of Max current Rmax(Ω) | Max power dissipation Pmax(W) | Dissipation factor (mW/C) | Thermal time constant (s) | Max impulse capacitance (uF)240VAC |
MF75-0.2/90 | 0.2 | 2600 | 90 | 0.004 | 55 | ≥90 | ≤650 | 15000 |
MF75-0.5/65 | 0.5 | 2600 | 65 | 0.006 | 11500 | |||
MF75-1/60 | 1 | 2600 | 60 | 0.008 | 11500 | |||
MF75-1.5/55 | 1.5 | 2600 | 55 | 0.01 | 11500 | |||
MF75-2/50 | 2 | 2600 | 50 | 0.011 | 11500 | |||
MF75-2.5/46 | 2.5 | 2800 | 46 | 0.012 | 11500 | |||
MF75-3/44 | 3 | 2800 | 44 | 0.015 | 11500 | |||
MF75-4/42 | 4 | 2800 | 42 | 0.018 | 8000 | |||
MF75-4.7/40 | 4.7 | 3000 | 40 | 0.021 | 9000 | |||
MF75-5/40 | 5 | 3000 | 40 | 0.022 | 8000 | |||
MF75-6.8/35 | 6.8 | 3200 | 35 | 0.025 | 8000 | |||
MF75-8/32 | 8 | 3200 | 32 | 0.028 | 6800 | |||
MF75-10/30 | 10 | 3200 | 30 | 0.03 | 6800 | |||
MF75-12/28 | 12 | 3200 | 28 | 0.033 | 6800 | |||
MF75-15/25 | 12 | 3200 | 25 | 0.04 | 6800 | |||
MF75-18/22 | 18 | 3200 | 22 | 0.055 | 6800 | |||
MF75-20/20 | 20 | 3200 | 20 | 0.065 | 6800 |
What is the detection method of NTC thermistor?
NTC is a thermistor with a negative temperature coefficient, that
is, the resistance becomes smaller as the temperature rises (in an
exponential relationship).
When testing, use the multimeter ohm level (depending on the
nominal resistance value to determine the level, generally R×1
level), the specific operation can be divided into two steps:
first, the room temperature test (the indoor temperature is close
to 25℃), and the alligator clip is used instead of the test pen to
clamp. The actual resistance of the two pins of the PTC thermistor
is measured and compared with the nominal resistance. The
difference between the two is within ±2Ω, which is normal. If the
actual resistance value differs too much from the nominal
resistance value, it means that its performance is poor or damaged.
Secondly, heating test. On the basis of normal temperature test,
the second step of test—heating test can be performed. Place a heat
source (such as an electric soldering iron) close to the thermistor
to heat it, and observe the universal indicator. Seeing that the
universal indicator changes with the increase of temperature, it
indicates that the resistance value is gradually changing (the
resistance of NTC thermistor with negative temperature coefficient
will become smaller, and the resistance of PTC thermistor with
positive temperature coefficient will become larger) , When the
resistance value changes to a certain value, the displayed data
will gradually stabilize, indicating that the thermistor is normal.
If the resistance value does not change, it indicates that its
performance has deteriorated and cannot be used continuously.
Pay attention to the following points when testing:
(1) Rt is measured by the manufacturer when the ambient temperature
is 25℃, so when measuring Rt with a multimeter, it should also be
carried out when the ambient temperature is close to 25℃ to ensure
the reliability of the test.
(2) The measured power shall not exceed the specified value, so as
to avoid the measurement error caused by the heating effect of the
current. (3) Pay attention to correct operation. During the test,
do not pinch the thermistor body with your hands to prevent the
body temperature from affecting the test.
(4) Be careful not to put the heat source too close to the PTC
thermistor or directly touch the thermistor to prevent it from
being burned.