I have a GK Backline 600 bass amp with some smokey thermistors. I pulled one out and it as the markings 15SP 007. Made by UEI. Now according to my searches, I can find the data sheet by UEI and this shows to be a 7 ohm, 15mm disk. On the schematic, it labels as NTC-1.3/7A This would leave me to believe that I'm looking for a 7A thermistor. But I'm still convinced it should be 7 ohm. Since one of them was completely destroyed, I ordered two replacements, closest I could get was 14.7mm at 7ohm NTC type. They immediately smoked at power up. That's when I finally found the schematic and realized I need two different kind.
NTC-1.3/7A
NTC-4/5A
as printed exactly on the schematic. For the life of me I can't figure out what to order. Any ideas? Keep in mind the clean one I pulled from the amp appears to be a 7 ohm kind, which makes sense with the label but not the schematic. Thanks for the help!
NTC-1.3/7A
NTC-4/5A
as printed exactly on the schematic. For the life of me I can't figure out what to order. Any ideas? Keep in mind the clean one I pulled from the amp appears to be a 7 ohm kind, which makes sense with the label but not the schematic. Thanks for the help!
look at the manufacturer's datasheet.
It shows these as current limiters for charging capacitor input filters.
The big part of any of these current limiters is what energy will be dissipated during first start up.
You need to decide what cold resistance your circuit needs to limit the inital current.
Then you need to select one that can dissipate the energy. That energy will depend on the voltage to the load and how long it lasts.
What is your NTC limiting?
Is it a soft start for a mains transformer?
Is it a slow charge for a capacitor bank (what they are designed to do)?
or something else?
is the load broken? That would cause an overload if it behaves as a short circuit.
It shows these as current limiters for charging capacitor input filters.
The big part of any of these current limiters is what energy will be dissipated during first start up.
You need to decide what cold resistance your circuit needs to limit the inital current.
Then you need to select one that can dissipate the energy. That energy will depend on the voltage to the load and how long it lasts.
What is your NTC limiting?
Is it a soft start for a mains transformer?
Is it a slow charge for a capacitor bank (what they are designed to do)?
or something else?
is the load broken? That would cause an overload if it behaves as a short circuit.
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