Andrew - the question was about voltages. I answered that question. Never mentioned the word 'current'.
You quoted only part of my post, I suggest you read the whole post and in context of the question that was asked I did also say that:
Even in single pair F5 the kits supplied by Jack used 5% source resistors and getting a 50mV difference between was not considered to be a problem as long as the offset was acceptable.
You quoted only part of my post, I suggest you read the whole post and in context of the question that was asked I did also say that:
Even in single pair F5 the kits supplied by Jack used 5% source resistors and getting a 50mV difference between was not considered to be a problem as long as the offset was acceptable.
Sangram, I did read your whole post.
I have re-read it in the light of your comment.
Your statement is still wrong.
I have re-read it in the light of your comment.
Your statement is still wrong.
The upper and lower currents are the same. The currents through the source resistors are the same. The voltage drop across the source resistor appears different if the source resistor values are not equal. That difference in voltage drop is due to unequal source resistor values. It is NOT due to mosFET tolerances.
Yes, but is a Zoble not supposed to be an impedance matching device?
Wikki says:
When used to cancel out the reactive portion of loudspeaker impedance, the design is sometimes called a Boucherot cell. In this case, only half the network is implemented as fixed components, the other half being the real and imaginary components of the loudspeaker impedance. This network is more akin to the power factor correction circuits used in electrical power distribution, hence the association with Boucherot's name.
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So I suppose that the Zobel would depend on the speaker?
Wikki says:
When used to cancel out the reactive portion of loudspeaker impedance, the design is sometimes called a Boucherot cell. In this case, only half the network is implemented as fixed components, the other half being the real and imaginary components of the loudspeaker impedance. This network is more akin to the power factor correction circuits used in electrical power distribution, hence the association with Boucherot's name.
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So I suppose that the Zobel would depend on the speaker?
Some amplifiers change gain with the load variation.
Some amplifiers change gain at HF and/or VHF when the load has a very high resistance.
In some situations this change of gain can result in stability margins changing to interfere with the output such that the amp performance is severely degraded.
One method of controlling what load the amplifier sees is to add a Zobel to the output so that the "change" in load at HF/VHF is reduced to what does not change the stability margins.
For the Zobel to work it MUST PASS HF signals and above.
It cannot do this if there is significant impedance @ these very high frequencies.
i.e. the Zobel ROUTE must tap into the output and feed back into the Return such that the total ROUTE inductance is kept VERY LOW.
The Zobel cannot work at very high frequencies if the ROUTE is many inches/centimeters long.
Some amplifiers change gain at HF and/or VHF when the load has a very high resistance.
In some situations this change of gain can result in stability margins changing to interfere with the output such that the amp performance is severely degraded.
One method of controlling what load the amplifier sees is to add a Zobel to the output so that the "change" in load at HF/VHF is reduced to what does not change the stability margins.
For the Zobel to work it MUST PASS HF signals and above.
It cannot do this if there is significant impedance @ these very high frequencies.
i.e. the Zobel ROUTE must tap into the output and feed back into the Return such that the total ROUTE inductance is kept VERY LOW.
The Zobel cannot work at very high frequencies if the ROUTE is many inches/centimeters long.
Yes, an effective Zobel works with high frequency signals.
It must be located in a route that is capable of passing high frequency signals
But, there is another Zobel that comes to our aid.
The speaker cables are interference pick up aerials.
They will inject interference into your amp box.
A Zobel at the chassis speaker terminals can be fitted to attenuate this cable interference.
This is the Pi filter that you see being referred to.
R+C at the amp,
L||R in the cable between amp and terminals.
R+C at the terminals.
It must be located in a route that is capable of passing high frequency signals
But, there is another Zobel that comes to our aid.
The speaker cables are interference pick up aerials.
They will inject interference into your amp box.
A Zobel at the chassis speaker terminals can be fitted to attenuate this cable interference.
This is the Pi filter that you see being referred to.
R+C at the amp,
L||R in the cable between amp and terminals.
R+C at the terminals.
I'm planning to build a First watt f5 V2 amp, with 4 output devices/channel.
Being a cheapskate, i'm wondering if I can use a pair of 600W/2x49V toroid transformers which I have modified by removing half of the secondary turns, so it's now a 2x25 volt transformer?
Is it still a 600W transformer?
Or do I have to replace all secondary windings with thicker wire? (which is very easy to do)
Being a cheapskate, i'm wondering if I can use a pair of 600W/2x49V toroid transformers which I have modified by removing half of the secondary turns, so it's now a 2x25 volt transformer?
Is it still a 600W transformer?
Or do I have to replace all secondary windings with thicker wire? (which is very easy to do)
, I've lived in the misconception that it's the size of the core that predicts the power transfer ability....