choosing a thermistor ?

[floyd]

How do I decide what value , etc. when choosing a thermistor , ( inrush current limiter ) to simulate the slow warm-up of a GZ34 for instance ? ... Weber uses these in their Copper Caps.

[kagliostro]

Are you sure Weber uses thermistors ?

I see nothing or resistors, not thermistors







Other thing will be to find a substitute for the old Brimistor (like the CZ4 used in the Vox AC50)

http://www.el34world.com/charts/Schematics/files/Vox/ac50_1.pdf

K

[floyd]

I'm looking at the guts right now.... diodes, followed by thermistor, followed by dropping resistors. But , of course , the thermistor value is obscured .

[kagliostro]

I'm looking at the guts right now.... diodes, followed by thermistor, followed by dropping resistors.

Which guts ?

K

[floyd]

I'm looking at the guts right now.... diodes, followed by thermistor, followed by dropping resistors.

Which guts ?

K

A weber GZ34 Copper cap module.

[kagliostro]

So you are saying that they sell something that is different from what they show in their's Kit reference pages ?

---

If you see the thermistor, can't you detect the model of the same by the label on the component ?

EDIT: May be you can find something of your interest here

http://www.ge-mcs.com/en/temperature/inrush-current-limiting/inrush-current-limiter.html

http://www.ge-mcs.com/download/temperature/920-325D-LR.pdf

http://www.ge-mcs.com/download/temperature/GE-THM_Curves.pdf

K

[floyd]

copper cap

[kagliostro]

I see, deleted label on the component

and more, that didn't seems the substitute for the GZ34 tube I was thinking



May be that is a substitute for the CZ4 Brimistor ??

I see only 3 diodes, can  you draw a (pencil) schematic ?

K

[floyd]

There are 4 diodes... one is hidden behind the thermistor. Weber makes , or made two Copper cap types... one is a plug in, and one is hard wired, like mine.

[kagliostro]

OK, sorry, I didn't know the existance of that version of the component

if the value is obscured using some kind of paint you can try to remove using solvent

if the label is abraded you can measure the resistance at cold and when warm

than you must read the explanation on the GE pdf I posted and try to recognize which

can be the right component to be used, you have the great luck that you can measure

the component

if you post here the cold and warm resistance values, may be some more experienced (than I'm)

member of the forum can give you a specific indication about what to use

K

[floyd]

another pic

[HotBluePlates]

Can you take a picture of the other side of the board?

The position of the component almost implies a varistor instead of a thermistor.

[floyd]

The components are in this order... from AC- rectifier diodes , then thermistor, then dropping/sag resistors.