Switching teams for a moment. I can see how a blown fuse would reduce ripple (if the fuse was after the de-ripplers. The next big thing, those). While a perfect fuse, would allow maximum flow, thus offer a higher ripple potential. Thus, max ripple may come from the good fuse, and any fuse degradation takes us towards less ripple. When measured at the reservoir caps.
This sort of thing probably can't be denied. Perhaps the quickest thing/fuse we could scope out, would be the anti surge fuse, with it's pigtail construction
https://res.cloudinary.com/rsc/imag...0,f_auto,q_auto,w_700/c_pad,w_700/F5412969-01
This sort of thing probably can't be denied. Perhaps the quickest thing/fuse we could scope out, would be the anti surge fuse, with it's pigtail construction
https://res.cloudinary.com/rsc/imag...0,f_auto,q_auto,w_700/c_pad,w_700/F5412969-01
This raises the next question to me. In Western Europe the share of wind/solar power is increasing. On some days, the total energy consumption of a country like Germany or the Netherlands is provided by wind and/or solar. Closer to home, your grid consumption can be zero when using solar or a home battery.
Wouldn't the sort of energy used for powering you audio system be audible? I mean a fuse causes only an ever so slight voltage drop in the power chain. But all of the power you use for your audio system is coming from the grid. That influence must be much greater, shouldn't it?
Wouldn't the sort of energy used for powering you audio system be audible? I mean a fuse causes only an ever so slight voltage drop in the power chain. But all of the power you use for your audio system is coming from the grid. That influence must be much greater, shouldn't it?
Audio does not care much where the energy comes from as long as it is relatively clean. The grids main suppliers are still generators driven by turbines. Sinusoid voltage created by devices that are really inductive so "real sinus". Solar and wind turbines create sinusoid voltage by means of electronic inverters. BTW no solar inverter or wind turbine is stronger than the grid. Even large Diesel generators used as backup (really) or for peak shaving do not "win" from the grid. Even if the generator is coupled erroneously at the wrong moment so unsynchronized the grid will quickly let the generator know who is boss.
It is important to build audio that can withstand higher grid voltages (253V due to either solar or windturbines) and filter out pollution regardless where that came from. It will not hurt to know which energy source has dirtiest voltage. Also pollution added by the person in front of the audio. Bluetooth, wireless, cell phone, LED lighting etc.
The voltage drop of a main fuse is negligable and of another league as for instance the voltage regulators inside a device. That same regulators that compensate the fluctuating mains voltage to a steady & clean DC 🙂 The audio circuits work on DC so if one invests in having a low noise ripple and pollution free DC that is where the gains are. So the simplest way to achieve results is to focus on having clean(er) DC and give less attention to AC as that is a factor one can not control except filtering. Not even with audiophile fuses 😀
It is important to build audio that can withstand higher grid voltages (253V due to either solar or windturbines) and filter out pollution regardless where that came from. It will not hurt to know which energy source has dirtiest voltage. Also pollution added by the person in front of the audio. Bluetooth, wireless, cell phone, LED lighting etc.
The voltage drop of a main fuse is negligable and of another league as for instance the voltage regulators inside a device. That same regulators that compensate the fluctuating mains voltage to a steady & clean DC 🙂 The audio circuits work on DC so if one invests in having a low noise ripple and pollution free DC that is where the gains are. So the simplest way to achieve results is to focus on having clean(er) DC and give less attention to AC as that is a factor one can not control except filtering. Not even with audiophile fuses 😀
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If we understand how a class AB works, we see that rail fuses have very little influence on output.
Considering the classic emitter follower stage output, voltage variations at the collector (VCB/VCE) pratically don't affect the output unless the amp aproaches clipping condition (VCE ---> 0).
Let's quantify:
Suppose a 0.5V variation on positive power supply rail due to fuse resistance (that's a lot) (2kHz AC supply in series in my simulation).
In a very simple, almost didatic, class AB power amp, shown below, that would reflect 200uV at the output.
More enhancements could be easily done in this circuit.
Considering 25V max output, that would be 0.0002/25=0.0008%
Very unlikely a human would be able to hear that.
Considering the classic emitter follower stage output, voltage variations at the collector (VCB/VCE) pratically don't affect the output unless the amp aproaches clipping condition (VCE ---> 0).
Let's quantify:
Suppose a 0.5V variation on positive power supply rail due to fuse resistance (that's a lot) (2kHz AC supply in series in my simulation).
In a very simple, almost didatic, class AB power amp, shown below, that would reflect 200uV at the output.
More enhancements could be easily done in this circuit.
Considering 25V max output, that would be 0.0002/25=0.0008%
Very unlikely a human would be able to hear that.
In rails they may do a good job doing what they are designed to do, they possibly also cost a woofer in DC coupled amplifiers when either one of them blows. Since the semis are shot anyway it pays off to not use DC fuses and include DC protection. Probably not in all amplifiers but usually the AC fuse will blow if things go wrong.
Just opinion based on experiences. I have had boutique brand amplifiers (so no DC protection) blowing just 1 of the rail fuses at power on. Medicine worse than the disease.
Just opinion based on experiences. I have had boutique brand amplifiers (so no DC protection) blowing just 1 of the rail fuses at power on. Medicine worse than the disease.
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There are many ways of mitigating the effects of a rail fuse failure, but the designer must implement them (not always true).
The power supply for the VAS can be made fully separate from the main rail, using a low power transformer, which I like for 2 other reasons:
-higher voltage to compensate voltages losses on output stage
-independency from the main power supply, which removes the load voltage variations, voltage ripple and any other spurious voltage variations, including the eventually fuse influence. This way, if a fuse blows, the VAS is still under control of the output voltage. Half wave would still go through, but an electronic DC sensor would mute the amp since average voltage would be non zero.
On top of that, we can add independent relay DC circuit protection on the output. If the user doesn't want the relay in series with the speaker, the relay can act in the transformer AC to shut the amp down completely. Contact resistence is <100mOhm and will follow the same analysis of the fuse influence (none).
And sure, AC fuse is a must.
The power supply for the VAS can be made fully separate from the main rail, using a low power transformer, which I like for 2 other reasons:
-higher voltage to compensate voltages losses on output stage
-independency from the main power supply, which removes the load voltage variations, voltage ripple and any other spurious voltage variations, including the eventually fuse influence. This way, if a fuse blows, the VAS is still under control of the output voltage. Half wave would still go through, but an electronic DC sensor would mute the amp since average voltage would be non zero.
On top of that, we can add independent relay DC circuit protection on the output. If the user doesn't want the relay in series with the speaker, the relay can act in the transformer AC to shut the amp down completely. Contact resistence is <100mOhm and will follow the same analysis of the fuse influence (none).
And sure, AC fuse is a must.
It used to cost only 2 cents for an opinion, and now it's 5 cents??? Damm inflation.
I wonder how much my thoughts are worth these days? Surely more than a penny.
Your thoughts are worth the cost of a fuse… It may blow your mind!
Regards, Gerrit
Regards, Gerrit