[MOVED] Please help on identifying a part

[danieljava]

Hi,

Does anyone know what this part is? It only has J marking on it. It has an impedances of about 60 Ohm that seems to go to 70 Ohm if I cool it down with an icepack and goes to around 50 Ohm when I use a hair drying to warm it up! I need to know what to order as a replacement.

Thanks in advance.

 

[betwixt]

.... well.... its a thermistor!

Your best bet is to note the resistance at two temperatures then search catalogs/data sheets for one with matching size and resistances.

Brian.

 

[FvM]

NTC disc diameter and thickness is also a criterion to select similar devices. The photo doesn't clarify if it's a sensor device (e.g. 5 mm diameter) or a power NTC, used e.g. as inrush current limiter.

 

[Calm down]

Judging from its appearance and features, this should be a thermistor, but the resistance value of 50-60 ohms is a bit strange. If it is used for temperature measurement, the resistance value is too small. If it is for surge suppression, the resistance value is too large. From the appearance, it is more likely to be for surge suppression. In this case, it has already been damaged.

 

[FvM]

50 - 60 ohm is well in range for inrush surrent supression of smaller power supplies up to a few 100 W. The NTC is hot in operation and resistance reduces to a few ohms.

 

[Calm down]

The working current of MF72 power type thermistor with a resistance of 50-60 ohms is relatively small because its thermal residual resistance is relatively large. Its diameter cannot be seen from the appearance, and it should not exceed 11mm diameter by visual inspection. Assuming it is not broken, the power supply it is suitable for should be below 100W and have good heat dissipation. Therefore, the thermistor can be heated with electricity to determine its residual resistance and whether it is damaged. The residual resistance and other parameters can be referred to in the attachment. Of course, it cannot be ruled out that there are other uncommon thermistors.

 

[FvM]

Why MF72? Obviously not the part shown in post #1.

 

[Calm down]

This is the closest model I can think of, but it seems that NTC cannot help 1 # find what he needs. If there is a closer answer to the truth, I am willing to learn.

 

[FvM]

I'd at least wait for dimension info before selecting possible candidates. Also rated current of the respective instrument in case it's mains inrush limiter.