Really not, about this subject i talk all i know
But i heard somewhere, someday, that those resistors inductance can create some problem.
That's the reason i was oppening to comments, and asking people to came in. and put their ideas.
I do not know, if we can consider this small inductance or not.
Exausted, mine knowledge memory department, related to emitter resistors, because now, i also include new informations, and ideas, from forum friends too.
Waiting more ideas, some new idea to increase our understanding related this subject.
regards,
Carlos
But i heard somewhere, someday, that those resistors inductance can create some problem.
That's the reason i was oppening to comments, and asking people to came in. and put their ideas.
I do not know, if we can consider this small inductance or not.
Exausted, mine knowledge memory department, related to emitter resistors, because now, i also include new informations, and ideas, from forum friends too.
Waiting more ideas, some new idea to increase our understanding related this subject.
regards,
Carlos
inductive resistors
Hi Carlos,
The box type resistors (5W & 10W type) are wire wound. They do have inductance and can cause some amps to become unstable or oscillate. There are also some standard-looking types that are wire wound.
Some other resistors also have inductance. The helical cut types may have a high enough inductance to affect the impedance within the passband of an amplifier. More trouble.
I am lucky enough to have an HP LCR meter (4263A). Expensive toy but very useful. I generally test the impedance of a resistor at 100, 1,000 and 100,000 Hz if needed. That is not often.
If you need to test, make a voltage divider with a carbon composition and the test resistor. Use a 'scope or wide band meter to measure the drop at different frequencies. Remember to check the oscillator output level at each frequency.
-Chris
Hi Carlos,
The box type resistors (5W & 10W type) are wire wound. They do have inductance and can cause some amps to become unstable or oscillate. There are also some standard-looking types that are wire wound.
Some other resistors also have inductance. The helical cut types may have a high enough inductance to affect the impedance within the passband of an amplifier. More trouble.
I am lucky enough to have an HP LCR meter (4263A). Expensive toy but very useful. I generally test the impedance of a resistor at 100, 1,000 and 100,000 Hz if needed. That is not often.
If you need to test, make a voltage divider with a carbon composition and the test resistor. Use a 'scope or wide band meter to measure the drop at different frequencies. Remember to check the oscillator output level at each frequency.
-Chris
Carbon Composition?
Hi Carlos,
I have to agree with Bricolo. You can find decent carbon film and metal film resistors that have a low enough inductance to not matter. Carbon composition tend to be noisy and change value with time.
If in doubt, just test your resistors of choice at different values. Circuit placement is what makes your choice important.
-Chris
Hi Carlos,
I have to agree with Bricolo. You can find decent carbon film and metal film resistors that have a low enough inductance to not matter. Carbon composition tend to be noisy and change value with time.
If in doubt, just test your resistors of choice at different values. Circuit placement is what makes your choice important.
-Chris
Hi Carlos,
Actually, the only way to be sure is to test them. "Flameproof" resistors can be good. The inductance varies by brand and type. What I am saying is that buying a particular type, like metal film, may not be safe in all cases.
Basically, test them. That way, if you have trouble with your resistors, it will be your fault and yours alone. Places in a circuit that only"see" DC with no ac component or spikes can use inductive resistors normally. So you don't have to throw any out either.
That's another way of saying that you can't always trust what you read or hear.
I'd say the same for capacitors or anything else.
-Chris
Actually, the only way to be sure is to test them. "Flameproof" resistors can be good. The inductance varies by brand and type. What I am saying is that buying a particular type, like metal film, may not be safe in all cases.
Basically, test them. That way, if you have trouble with your resistors, it will be your fault and yours alone. Places in a circuit that only"see" DC with no ac component or spikes can use inductive resistors normally. So you don't have to throw any out either.
That's another way of saying that you can't always trust what you read or hear.
I'd say the same for capacitors or anything else.
-Chris
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