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Capacitor help

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Felto1

New Member
Can someone help me with a capacitor that's on board that I cannot identify. It is clear with strips on it.
It is not a resistor. It does not have any markings on it. it has a green and an orange strip going across it.

Does anyone know what the value would be for this capacitor? thanks in advance.
 

MikeMl

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Can you post a picture?
 

MikeMl

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I have some that look like that in my junkbox (different colors). I have never figured out how to read them...
 

ronsimpson

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How do you know it is a capacitor?
Have you remove one and tried to measure the capacitance?
upload_2017-2-23_19-49-43.png
 
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vtech

Active Member
Not sure but I don't believe it is a capacitor?
I used to see something almost identical on many of the Phone line related equipment. It was meant for protection against lightning/surge on the signal lines. --also known as arrestor/sidactor..etc. The color bands denoted rating but I do not exactly recall.

If that is the device, it should not measure anything on a meter either way since it is an open crowbar.
Another giveaway is to look at the odd numbering nomenclature if mounted on a PCB. such as cx,sc,tc etc.
Pix attachedpart.jpg
 

kubeek

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Why do you think that is a capacitor? It looks more like a diode would look like, guessing a zenere diode by the color stripes.
 

EvilGenius

Member
Why do you think that is a capacitor? It looks more like a diode would look like, guessing a zenere diode by the color stripes.
Looking at it twice, I believe you are right Kubeek. It looks like a zener diode. Or a surge arrester.

Edit: After a bit of research, the color bands follow something similar to resistors. The wider band is your start color (anode). In this case you have orange, blank, green, black.
I believe the numbers will read: 1N3051
If it is the case, it is a Zener diode, Microsemi, Vz=200V, Iz=4.6, Resistance 1500 Ohms.
Place your voltmeter on the Orange pin to positive and black to negative and see what you read?
Also if you have a photo of PCB from the above, it might give us additional clues.
Regards,
EG
 
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ronsimpson

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Not sure but I don't believe it is a capacitor?
I think it is a spark gap / ark arrestor /voltage limiting/ thing.
I find them on telephone equipment to limit voltage (lightning).
This type is used on small TV sets (CRT) and small monitors (CRT).
 

ronsimpson

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Here is a picture of a spiral cut film resistor. The resistive mater is cut to make a long thin piece.

A ark arrestor is made just like the resistor BUT the cut(s) are all the way around. This way not current will flow. The width of the cut sets the breakdown voltage. When the voltage is too high current flows. Usually found in a clear glass enclose, so you can see if it is burned out.

It will measure very high resistance. You probably will see open circuit.
The capacitance is very low. 5pF at most.
 

Chris Edwards

New Member
A capacitor is a passive two-terminal electrical component that stores electrical energy in an electric field. Capacitor is an electronic component that stores electric charge. The capacitor is made of 2 close conductors (usually plates) that are separated by a dielectric material. One of the advantages of the capacitor is that there is very little change of capacitance with time and voltage applied. This type of capacitor is also used for low frequencies, with 100 kHz or so being the upper limit.
 

kubeek

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A capacitor is a passive two-terminal electrical component that stores electrical energy in an electric field. Capacitor is an electronic component that stores electric charge. The capacitor is made of 2 close conductors (usually plates) that are separated by a dielectric material. One of the advantages of the capacitor is that there is very little change of capacitance with time and voltage applied. This type of capacitor is also used for low frequencies, with 100 kHz or so being the upper limit.
Yeah, we all know wikipedia. The point being?
 

Rich D.

Active Member
I don't know much about much, but that ain't no capacitor. Since the Lyden jar lost its popularity, who makes capacitors in glass envelopes?
 
Good Morning ! I agree with Kubeek, it looks more like a diode (possibly a signal diode) e.g., 1N34, etc.. It is possible also that it is in the circuit for surge protection (e.g., crowbar device). If you can tell us what is silkscreened onto the circuit board for it's designation, that would be very helpful in identification. What is the circuit board, that this component is on, from ? That may help identify it as well, at least it will be a possible hint..
 
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