Through Hole Power NTC Thermistor Chip MF72 10D-5 10Ohm 5mm 0.7A Pitch 5mm 6mW Negative Temperature Coefficient Resistor
OUTLINE
This is a Negative Temperature Coefficient Resistor Whose resistance changes with ambient temperature changes. Thermistor comprises 2 or 4 kinds of metal oxides of iron, nickel,cobalt, manganese and copper, being shaped and Sintered at high temperature(1200 to 1500 )
Applications
Conversion power supply, switch power, UPS power, Kinds of electric heter, electronic energy-saving lamps, electronic ballast etc all kinds of power cicuit proterction of electronic equipments, filament proterction of CRT, bulb and other lighting lamps.
Dimension and Performances
| Type |
Rated Resistance |
(A) | D | L | F |
Dimensions (Unit:mm) |
|
|
Max. Steady State Current |
Dmax | Lmin | F±1 | Tmax | d | ||
| 5D-5 | 5 | 1 | 6.5 | 25 | 5.0/2.5 | 5 | 0.55/0.45 |
| 10D-5 | 10 | 0.7 | 6.5 | 25 | 5.0/2.5 | 5 | 0.55/0.45 |
| 20D-5 | 20 | 0.5 | 6.5 | 25 | 5.0/2.5 | 5 | 0.55/0.45 |
What is an NTC thermistor?
A thermistor is essentially a resistor that changes its electrical resistance at varying temperatures. The name is derived from a mix of thermal and resistor. They are used in washing machines, tumble dryers and even fridges and freezers as thermostats or temperature sensitive safety cut out devices. Because their electrical resistance at various temperatures is known, it’s easy for the appliance to monitor a thermistor and detect when certain temperatures are reached.
How to test an NTC thermistor
Unless you can see a wire has come loose you are unlikely to see anything physically wrong. Diagnosis is done by measuring the resistance with a continuity (or multi) meter. I can’t give readings for all thermistors because they vary, especially in different types of appliance, but you should be able to get a reading across both terminals. If it’s completely open circuit it’s likely to be faulty.
Readings on a washing machine’s NTC thermistor for example may be something like 12000 Ohm at 25°C or 3243 Ohm at 60 ° C. The resistance at 0 ° C may be more like 36000 Ohm. However, it may be possible for readings to be present but incorrect. For example, the resistance figures I can see in an old Hotpoint washing machine manual qualify the resistance readings by saying plus or minus 6% for the resistance at 0° down to plus or minus 2% for the resistance at 60° implying that readings outside these parameters are incorrect. Therefore without the exact reading expected for any individual thermistor you can’t be sure if it is correct or not.
If you get no resistance reading at all (open circuit) then it’s probably faulty but you should at least check it at different temperatures by placing one in a saucer of warm water for example and carefully adding freshly boiled. The hotter the temperature the less resistance should be measured.
What does NTC stand for?
NTC stands for Negative Temperature Coefficient which basically means that their electrical resistance decreases with increasing temperature.
