In your daily life, you use many electronic appliances. Maximum appliances used at home consist of an electric component known as a resistor. These resistors are mostly used in heaters, light bulbs, microwaves, electric stoves, toasters, and other heating appliances. In an electronic circuit, the flow of the current or limits of current is done by a resistor. To provide a particular voltage range for an active device, resistors are used as transistors.
You will get efficient and thoughtful service from Xieyuan Electronic.
Resistors are classified into two types. These types of resistors are further divided into subcategories. The types of resistors are as follows:
The current in the linear resistor will be directly proportional to the voltage applied to the resistor. The resultant graph of the linear resistor will be between the current (I) and voltage (V). The linear resistor graph will have a straight I-V curve.
Linear resistors are further divided into two types:
Fixed resistors have specific values, and these specific values cannot be changed. These fixed resistors are used for the appliance which never needs to change their value.
Variable resistors have values that can be varied or changed, and these variable values can be changed using a dial, screw, button, or knob. These variable resistors are used for appliances like radios with knobs, lights with switches, and television.
The current in the non-linear resistor will be indirectly proportional to the voltage applied to the resistor. Current In the resistor changes with the exchange in the temperature or voltage exchange. Values of non-linear resistors aren&#;t changed according to Ohm&#;s law. The resultant graph of the non-linear resistor will be between the current (I) and voltage (V). The non-linear resistor graph will have a non-linear I-V curve.
Non-linear resistors are further divided into three types:
Thermistors resistors are a kind of variable resistors. Thermistors identify the temperature change. These thermistor resistors have two terminals, and it is sensitive to temperature. The resistance value of the thermistor resistor is inversely proportional to the temperature.
A non-linear varistor resistor is made of semiconductors. The current through the varistor depends non-linearly on the voltage applied across the resistor. The most commonly used form for the varistor resistor is MOV or metal oxide varistor.
Photo resistors are also called LDR (light-dependent resistors). The other names of the photo resistors are photoconductive cells and light-controlled variable resistors. The photoresistor&#;s resistance decreases with an increase in the intensity of the incident light. So, the photoresistor&#;s resistance is inversely proportional to the intensity of the incident light.
The fixed and variable resistors are types of resistors called linear resistors. These fixed and variable resistors are further classified into sub-categories.
There are seven types of resistor, including the fixed resistor, which are as follows:
A form of a passive component is called a wire-wound resistor. A wire wound resistor is created by wrapping metal wire around a metal core. The metal wire serves as the electric current&#;s resistive component. Thus, the metal wire restricts a specific level of electric current. As a non-conductive substance, the metal core is placed. As a result, it blocks the flow of electric current.
The most precise and reliable parts to employ to limit the flow of electric current to a specific level are foil resistors. Compared to other types of resistors, foil resistors generate little noise. The TCR (Temperature Coefficient of Resistance) of foil resistors is low.
A passive component that limits the flow of electric current to a set level is a resistor made of carbon called a carbon composition resistor. The cylindrical resistive element used to create the carbon composition resistors has integrated metal end caps. The ceramic and carbon powder combination is used to create the cylindrical resistive element of the carbon composition resistor. The carbon powder effectively conducts electric current.
The carbon film resistor is the most common type of resistor used in electrical circuits. The carbon film is applied to a ceramic substrate to create the carbon film resistors. The ceramic substrate serves as an electrical current insulator, while the carbon sheet functions as a resistive element to the current.
A form of a passive component known as a metal film resistor uses metal film to limit the flow of electric current to a specific level. In contrast to metal film resistors, which use chromium, nickel, tin, and antimony to create their films, carbon is used to create the film in carbon film resistors. The TCR (temperature coefficient of resistance) of metal film resistors is low.
The metal glaze resistor is a passive component used to limit the flow of electric current to a certain level by combining glass powder with metal particles. Low TCR (temperature coefficient of resistance) for metal glaze resistors.
A form of a passive component known as a metal oxide film resistor uses metal oxide film as the resistive element to limit the flow of electric current to a specific level. Metal oxide film resistor construction is virtually identical to metal film resistors.
There are seven types of the resistor of variable resistor, which are as follows:
Three terminals make up the potentiometer, two fixed and one movable. The track&#;s two resistive ends are linked to the potentiometer&#;s two fixed terminals, while the third terminal is connected to the slider or sliding wiper. The current flow in the potentiometer decreases when the resistance of the potentiometer is increased.
Humistor name is the combination of humidity and resistor. Humidity affects humistors quite strongly. Resistive humidity sensors and humidity-sensitive resistors are other names for humidistats.
Rheostats are built in a manner that is virtually identical to potentiometers. However, we utilize two terminals of a rheostat to act. The length of the resistive element or track through which the electric current flows determines the rheostat&#;s resistance.
Resistance of Thermistors depends on the surrounding temperature change. Positive temperature coefficient (PTC) and negative temperature coefficient (NTC) thermistors are the two types of thermometers. While PTC thermistors experience an increase in resistance as the temperature rises, NTC thermistors experience a reduction in resistance as the temperature rises.
The resistance of the magneto resistor varies when a magnetic field is supplied to the magneto resistor. Similarly, the magneto resistor&#;s resistance dropped as the magnetic field&#;s strength increased.
The word photoresistor is the combination of the terms photon and resistor. The photoresistor experiences a change in resistance when light energy is applied. As the applied light intensity rises, the photo resistor&#;s resistance falls.
As the name indicates, the force-sensitive resistors are extremely sensitive to the applied force. Force sensors, pressure sensors, force-sensing resistors, or FSR are other names for force-sensitive resistors.
Things to Consider When Using Various Types of Resistors
Power dissipation and temperature coefficients are the two factors to be mindful of when using a type of resistor.
Power Dissipation: Power dissipation is an important consideration when selecting a resistor. Always select a resistor with a lower power rating than the current being passed through it. So, choose a resistor with a power rating at least twice as high.
Temperature Coefficients: The most important thing to remember when working with resistors is that they must be used at high temperatures or else the resistance will flow dramatically. The temperature coefficient of a resistor is classified as either negative or positive (PTC).
The value of the resistor isn&#;t displayed outside. Through the color pattern, the resistance of the resistor can be calculated. The (PTH) plated-through-hole resistors use the color coding system; these colors add flair to the circuit when connected. In the case of (SMD) surface mount device resistors, they have their value marking system.
The color codes of the resistors are as follows:
ColorColor codeBlack
0
Brown
1
Red
2
Orange
3
Yellow
4
Green
5
Blue
6
Violet
7
Gray
8
White
9
The value of the resistor of the deviation from the nominal value is known as the tolerance of resistors. This value is expressed with the ±% symbol. The resistor&#;s tolerance is used to identify the resistor, giving a more accurate resistance reading.
Tolerance of the resistor according to the color:
ColorToleranceBrown
±1%
Red
±2 %
Gold
±5%
Silver
±10%
Wire applications wrapped resistors kind of include shunt with ampere meters which essentially used for accurate measurement, high sensitivity very balanced current regulation in a generally major way.
Photo resistors are used in various products, including photography equipment, burglar alarms, and flame detectors in a pretty big way.
Voltmeter and temperature control generally is controlled by resistors, contrary to popular belief.
Amplifiers, telephony, oscillators, and digital multimeters all need resistors, which is particularly significant. They are also utilized in transmitters, demodulators, and modulators, which are particularly fairly significant.
Resistors are part of appliances used in daily life. These resistors are used in circuits. Practical work with resistors will help to know the usage and working of the resistor in the circuit. In physics, resistors are to know the behavior of different resistors, i.e., the flow of the current, voltage flow, etc.
There are many different types of resistors. Each type of resistor is used in different circuits according to their behavior. To know which type of resistor should be used in the circuit, the color of the type of resistor table should be referred to.
A. There are many types of resistors. The main classification of resistors is two types that are linear and nonlinear. These are further divided into subcategories. The linear resistors are divided into fixed and variable resistors. The nonlinear resistors are divided into a thermistor, photoresistor, varistor, and surface mount resistor.
A. Flameproof wire wound resistors are used in the chargers as chargers are the input devices. The limited current should supply from the charger as a wire wound resistor is created by wrapping metal wire around a metal core. The metal wire serves as the electric current&#;s resistive component. Thus, the metal wire restricts a specific level of electric current. As a non-conductive substance, the metal core is placed. As a result, it blocks the flow of electric current. So the chargers will be working without any high voltages.
Ans. The type of resistor used in a bulb is tungsten. The filament in the bulb doesn&#;t have a specific resistance level, so when the voltage through the bulb has increased, the current is also increased. The increase in current results in the temperature of the bulb. As a result, the bulb glows.
bill williams
#
I am currently rebuilding some old test gear, and one piece in particular is a B&K tube tester from the mid-late 50s. In going through the schematic & parts list, almost all the resistors were identified as 'glass' and almost all the glass resistors had a tolerance of 5%...some had 10%.
In all my dealings with electronics, I haven't come across this description of a resistor. Can someone shed some light on what exactly a glass resistor is and its major characteristics? (pointers to correct descriptions?) Are they WW? carbon film? etc.
My initial reaction was a resistor encased in a glass tube to shield the resistor from effects of moisture, but I am not sure about that because with a tolerance of 5%, changes in resistance due to moisture would be small in comparison to any variation due to 5% tolerance. Perhaps long term stability is of concern?
It is not clear that I need to replace any of these glass resistors, but if I do, I don't know the appropriate material to use, e.g. metal film, etc., without understanding what I'll be trading off.
With much appreciation,-John
[Non-text portions of this message have been removed]
Want more information on glass glaze resistor? Feel free to contact us.
tronix_cal
#
I am currently rebuilding some old test gear, and one piece in
particular is a B&K tube tester from the mid-late 50s. In going
through the schematic & parts list, almost all the resistors were
identified as 'glass' and almost all the glass resistors had a
tolerance of 5%...some had 10%.
In all my dealings with electronics, I haven't come across this
description of a resistor. Can someone shed some light on what
exactly a glass resistor is and its major characteristics? (pointers
to correct descriptions?) Are they WW? carbon film? etc.
My initial reaction was a resistor encased in a glass tube to shield
the resistor from effects of moisture, but I am not sure about that
because with a tolerance of 5%, changes in resistance due to moisture
would be small in comparison to any variation due to 5% tolerance.
Perhaps long term stability is of concern?
It is not clear that I need to replace any of these glass resistors,
but if I do, I don't know the appropriate material to use, e.g. metal
film, etc., without understanding what I'll be trading off.
With much appreciation,-John
Corning made a metal film over glass resistor, and Richey also made aglass encased metal film resistor. I've seen them used in aircraft UHFtransmitters, only time I've seen one - low capacity?. The Corningunits are usually grey enamel over the film, which is on the glassrod/substrate "core" and usually have the Corning "CGW" printed on them...On 03/06/ 04:49 PM, bill williams uniquelogin@...[TekScopes] wrote:
Bruce Griffiths
#
Victoreen used to make glass encapsulated high value carbon film resistors.
Bruce
toggle quoted message
Show quoted textOn 07 March at 10:49 "bill williams uniquelogin@... [TekScopes]" <TekScopes@...> wrote:
I am currently rebuilding some old test gear, and one piece in particular is a B&K tube tester from the mid-late 50s. In going through the schematic & parts list, almost all the resistors were identified as 'glass' and almost all the glass resistors had a tolerance of 5%...some had 10%.
In all my dealings with electronics, I haven't come across this description of a resistor. Can someone shed some light on what exactly a glass resistor is and its major characteristics? (pointers to correct descriptions?) Are they WW? carbon film? etc.
My initial reaction was a resistor encased in a glass tube to shield the resistor from effects of moisture, but I am not sure about that because with a tolerance of 5%, changes in resistance due to moisture would be small in comparison to any variation due to 5% tolerance. Perhaps long term stability is of concern?
It is not clear that I need to replace any of these glass resistors, but if I do, I don't know the appropriate material to use, e.g. metal film, etc., without understanding what I'll be trading off.
With much appreciation,-John
#
The modern hermetically sealed glass resistors I have seen are
extremely high values with tight tolerances where contamination would
be a serious problem.
If the resistors are used at high voltages, then high voltage thin or
thick film resistors are probably suitable replacements.
toggle quoted message
Show quoted textI am currently rebuilding some old test gear, and one piece in particular is a B&K tube tester from the mid-late 50s. In going through the schematic & parts list, almost all the resistors were identified as 'glass' and almost all the glass resistors had a tolerance of 5%...some had 10%.
In all my dealings with electronics, I haven't come across this description of a resistor. Can someone shed some light on what exactly a glass resistor is and its major characteristics? (pointers to correct descriptions?) Are they WW? carbon film? etc.
My initial reaction was a resistor encased in a glass tube to shield the resistor from effects of moisture, but I am not sure about that because with a tolerance of 5%, changes in resistance due to moisture would be small in comparison to any variation due to 5% tolerance. Perhaps long term stability is of concern?
It is not clear that I need to replace any of these glass resistors, but if I do, I don't know the appropriate material to use, e.g. metal film, etc., without understanding what I'll be trading off.
With much appreciation,-John
On Mon, 6 Mar 21:49:20 + (UTC), you wrote:
Fabio Trevisan#
The modern hermetically sealed glass resistors I have seen are
extremely high values with tight tolerances where contamination would
be a serious problem.
If the resistors are used at high voltages, then high voltage thin or
thick film resistors are probably suitable replacements.
On Mon, 6 Mar 21:49:20 + (UTC), you wrote:I am currently rebuilding some old test gear, and one piece in particularis a B&K tube tester from the mid-late 50s. In going through the schematic
& parts list, almost all the resistors were identified as 'glass' and
almost all the glass resistors had a tolerance of 5%...some had 10%.In all my dealings with electronics, I haven't come across thisdescription of a resistor. Can someone shed some light on what exactly a
glass resistor is and its major characteristics? (pointers to correct
descriptions?) Are they WW? carbon film? etc.resistor from effects of moisture, but I am not sure about that because
My initial reaction was a resistor encased in a glass tube to shield the
with a tolerance of 5%, changes in resistance due to moisture would be
small in comparison to any variation due to 5% tolerance. Perhaps long
term stability is of concern?if I do, I don't know the appropriate material to use, e.g. metal film,
It is not clear that I need to replace any of these glass resistors, but
etc., without understanding what I'll be trading off.With much appreciation,-John
Hi Bill,I think the term is not very used anymore but I think it refers to theresistors' insulation material and, being glass (instead of lacquer), it'scapable of withstanding higher voltage.For relatively high value resistors, for which voltage is not limited byits power rating, a regular lacquer coated resistor is rated at around 300Vwhile a "not so special" glass coated resistor can withstand 3kV (again, aslong it's not being limited by the dissipated power).In Brazil is still common, if you go to a parts store and ask the salesmanfor a high voltage rating resistor, they refer to it as "glass" resistors.Nowadays, it's much more about the ratings and the different brands'classes / categories and one is no longer much more concerned as of whatmaterial the darn thing is made of, as long as it meets the specs... Butback when that particular quality was introduced (e.g. such as being ableto stand 3kV) the term was coined relating that particular outstanding specto the material that it was made of.I'm not sure, today, if all resistors capable to stand 3kV are necessarilycoated with glass, or if there maybe new materials that do as as good as.Brgrds,FabioOn Mar 6, 6:50 PM, "bill williams uniquelogin@...[TekScopes]" wrote:[Non-text portions of this message have been removed]
David Holland
#
The modern hermetically sealed glass resistors I have seen are
extremely high values with tight tolerances where contamination would
be a serious problem.
If the resistors are used at high voltages, then high voltage thin or
thick film resistors are probably suitable replacements.
On Mon, 6 Mar 21:49:20 + (UTC), you wrote:I am currently rebuilding some old test gear, and one piece in particular is a B&K tube tester from the mid-late 50s. In going through the schematic & parts list, almost all the resistors were identified as 'glass' and almost all the glass resistors had a tolerance of 5%...some had 10%.
In all my dealings with electronics, I haven't come across this description of a resistor. Can someone shed some light on what exactly a glass resistor is and its major characteristics? (pointers to correct descriptions?) Are they WW? carbon film? etc.
My initial reaction was a resistor encased in a glass tube to shield the resistor from effects of moisture, but I am not sure about that because with a tolerance of 5%, changes in resistance due to moisture would be small in comparison to any variation due to 5% tolerance. Perhaps long term stability is of concern?
It is not clear that I need to replace any of these glass resistors, but if I do, I don't know the appropriate material to use, e.g. metal film, etc., without understanding what I'll be trading off.
With much appreciation,-John
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Posted by: David <davidwhess@...>
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Yahoo Groups Links
I'd consider neither criteria applicable in a standard service gradetube tester from B&K in the 50's. 300V resistors might be a littlelow on the voltage rating, but 450V's would likely be more thansufficient.All I've ever seen in a service grade tube tester is standard carboncomp's, an occasional power resistor, and *maybe* a precision wirewound buried away in the meter. Service grade testers aren'texactly precision equipment. Perhaps the wiz-bang Hickok's arebetter, but I wouldn't hold my breath.What make and model of B&K tester?On Mon, Mar 6, at 7:00 PM, David davidwhess@... [TekScopes] wrote:
Dennis Tillman W7pF
#
Tube testers do not use unusually high voltages. 200V volts is more than enough to test all of the + tube types used in common appliances (radios, TVs, stereo's, etc). Many tube testers test at much lower voltages.
You can tell most of what you need to know about the quality of a tube at lower plate voltages (under 100V). One exception are gas filled tubes like voltage regulators which need at least 80 to 100V to start the gas conducting current.
Dennis Tillman W7PF
toggle quoted message
Show quoted textThe modern hermetically sealed glass resistors I have seen are
extremely high values with tight tolerances where contamination would
be a serious problem.
If the resistors are used at high voltages, then high voltage thin or
thick film resistors are probably suitable replacements.
On Mon, 6 Mar 21:49:20 + (UTC), you wrote:I am currently rebuilding some old test gear, and one piece in particular is a B&K tube tester from the mid-late 50s. In going through the schematic & parts list, almost all the resistors were identified as 'glass' and almost all the glass resistors had a tolerance of 5%...some had 10%.
In all my dealings with electronics, I haven't come across this description of a resistor. Can someone shed some light on what exactly a glass resistor is and its major characteristics? (pointers to correct descriptions?) Are they WW? carbon film? etc.
My initial reaction was a resistor encased in a glass tube to shield the resistor from effects of moisture, but I am not sure about that because with a tolerance of 5%, changes in resistance due to moisture would be small in comparison to any variation due to 5% tolerance. Perhaps long term stability is of concern?
It is not clear that I need to replace any of these glass resistors, but if I do, I don't know the appropriate material to use, e.g. metal film, etc., without understanding what I'll be trading off.
With much appreciation,-John
------------------------------------
Posted by: David <davidwhess@...>
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------------------------------------
Yahoo Groups Links
-----Original Message-----From: TekScopes@... [mailto:TekScopes@...]Sent: Monday, March 06, 4:43 PMTo: : Re: [TekScopes] Glass resistors - characteristics?I'd consider neither criteria applicable in a standard service gradetube tester from B&K in the 50's. 300V resistors might be a littlelow on the voltage rating, but 450V's would likely be more than sufficient.All I've ever seen in a service grade tube tester is standard carbon comp's, an occasional power resistor, and *maybe* a precision wirewound buried away in the meter. Service grade testers aren'texactly precision equipment. Perhaps the wiz-bang Hickok's are better, but I wouldn't hold my breath.What make and model of B&K tester?On Mon, Mar 6, at 7:00 PM, David davidwhess@... [TekScopes] wrote:------------------------------------Posted by: David Holland ------------------------------------------------------------------------Yahoo Groups Links
#
It is a model 700. For the curious, the manual can be found here:Looking at the schematic, the highest voltage is approx 400 VDC.I think Favio comment about the insulation quality is somewhat on point. They wanted to achieve a higher breakdown voltage. Still a little strange to me as I had my head in a lot of tube TVs in the mid 60s and don't remember glass resistors - then again, I was (very) young and poking around my dad's shop.Also, Favio comment triggered a long forgotten repair effort. I accidently crushed the resistor in a 30KV HV probe that was used to check cathode voltage on CRTs. Disassembling it resulted in finding a long wire wound resistor on a glass rod (or form-dont recall) all encased in a glass tube. I assume the glass was for insulation/breakdown voltage....So to be safe, I guess I should try to find resistors that have at least a 400v breakdown voltage, and probably 450 v or higher would be better...
David Holland
#
It is a model 700. For the curious, the manual can be found here:
http://bama.edebris.com/manuals/b&k/700/ http://bama.edebris.com/manuals/b&k/700/
Looking at the schematic, the highest voltage is approx 400 VDC.
I think Favio comment about the insulation quality is somewhat on point. They wanted to achieve a higher breakdown voltage. Still a little strange to me as I had my head in a lot of tube TVs in the mid 60s and don't remember glass resistors - then again, I was (very) young and poking around my dad's shop.
Also, Favio comment triggered a long forgotten repair effort. I accidently crushed the resistor in a 30KV HV probe that was used to check cathode voltage on CRTs. Disassembling it resulted in finding a long wire wound resistor on a glass rod (or form-dont recall) all encased in a glass tube. I assume the glass was for insulation/breakdown voltage....
So to be safe, I guess I should try to find resistors that have at least a 400v breakdown voltage, and probably 450 v or higher would be better...
J
[Non-text portions of this message have been removed]
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Posted by: uniquelogin@...
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Yahoo Groups Links
If I read (quickly skim) the parts list right.. (and there isn't amissing decimal point.)..All those "glass" resistors look like 3W, or 7W power resistors to me.If I recall correctly, carbon comps were generally available up toabout 2W, and after that you had to get more esoteric. Butgenerally speaking, beyond power dissipation, higher wattage resistors(usually) have higher voltage ratings as well.I don't think there's much of anything special about those resistorsbeyond their power rating.In your 30KV probe example, in that case, yes, they wanted the highervoltage rating. In this case, I don't think it matters much. Iagree with Dennis, I think the most anything is going to see is about200V.IMHO, YMMV, of course...DavidOn Mon, Mar 6, at 8:25 PM, uniquelogin@... [TekScopes] wrote:
Ed Breya
#
I think Fabio called it right - it's glass coating. There may be some confusion in the terminology used over the years - I'd guess that the original part type is the common vitreous enamel (like a molten glass glaze used in ceramics) coated wirewound power resistor. The wire is wound on a ceramic slug, and the outside is glazed, which makes a good high temperature insulation and seal.
Unless the parts were cooked or otherwise damaged, they should be impervious to most environment factors, and should not need replacement.
Ed
#
That fits with some modern high voltage and high value film resistorsbeing labeled "glazed". Except for thick film resistors, I alwaysconsidered film resistors to be low voltage until I ran across these.(1)Like I have described in the past, Tektronix replaced the carboncomposition resistors in high voltage circuits in the late 22xx serieswith film resistors which seem to be related to the currently producedVR or HVR film resistors (2) and the former are described as "glazed"but I wonder what the difference is between these are and why one isspecified to be glazed and the other is not:Even at 100s of volts, I would use these types of high voltage filmresistors to get enough voltage derating for reliability.(1) Looking up metal glaze resistor reveals what is going on. They*are* thick film resistors made from metal and glass powder fired ontoa substrate.(2) I never found specifications for the Mepco/Centralab resistorsthat Tektronix used to replace the carbon composition resistors inhigh voltage applications but I did find a reference indicating thatthey became or were equivalent to the VR series of high voltage filmresistors.
toggle quoted message
Show quoted textHi Bill,
I think the term is not very used anymore but I think it refers to the
resistors' insulation material and, being glass (instead of lacquer), it's
capable of withstanding higher voltage.
For relatively high value resistors, for which voltage is not limited by
its power rating, a regular lacquer coated resistor is rated at around 300V
while a "not so special" glass coated resistor can withstand 3kV (again, as
long it's not being limited by the dissipated power).
In Brazil is still common, if you go to a parts store and ask the salesman
for a high voltage rating resistor, they refer to it as "glass" resistors.
Nowadays, it's much more about the ratings and the different brands'
classes / categories and one is no longer much more concerned as of what
material the darn thing is made of, as long as it meets the specs... But
back when that particular quality was introduced (e.g. such as being able
to stand 3kV) the term was coined relating that particular outstanding spec
to the material that it was made of.
I'm not sure, today, if all resistors capable to stand 3kV are necessarily
coated with glass, or if there maybe new materials that do as as good as.
Brgrds,
Fabio
On Mar 6, 6:50 PM, "bill williams uniquelogin@...
[TekScopes]" <TekScopes@...> wrote:
The modern hermetically sealed glass resistors I have seen are
extremely high values with tight tolerances where contamination would
be a serious problem.
If the resistors are used at high voltages, then high voltage thin or
thick film resistors are probably suitable replacements.
On Mon, 6 Mar 21:49:20 + (UTC), you wrote:I am currently rebuilding some old test gear, and one piece in particularis a B&K tube tester from the mid-late 50s. In going through the schematic
& parts list, almost all the resistors were identified as 'glass' and
almost all the glass resistors had a tolerance of 5%...some had 10%.In all my dealings with electronics, I haven't come across thisdescription of a resistor. Can someone shed some light on what exactly a
glass resistor is and its major characteristics? (pointers to correct
descriptions?) Are they WW? carbon film? etc.resistor from effects of moisture, but I am not sure about that because
My initial reaction was a resistor encased in a glass tube to shield the
with a tolerance of 5%, changes in resistance due to moisture would be
small in comparison to any variation due to 5% tolerance. Perhaps long
term stability is of concern?if I do, I don't know the appropriate material to use, e.g. metal film,
It is not clear that I need to replace any of these glass resistors, but
etc., without understanding what I'll be trading off.With much appreciation,-John
[Non-text portions of this message have been removed]
On Mon, 6 Mar 21:07:02 -, you wrote: