High efficiency, there's a heatsink bump under the chip, which could be mounted on something with a bit of mass, if needed. Effective delivery of high power can be done with tiny bits of hardware - the DIY chip amp I did had its important bits in as tiny a space - all the bulk of the amplifier was in the power supply, the heatsinks, and the smoothing capacitors surrounding the amp chip. Spreading the working bits around the place is asking for trouble - squash everything in tight, and then get rid of heat as efficiently as possible.
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Thoughts on power conditioners?
- Thread starter Keith_W
- Start date
High efficiency, there's a heatsink bump under the chip, which could be mounted on something with a bit of mass, if needed. Effective delivery of high power can be done with tiny bits of hardware - the DIY chip amp I did had its important bits in as tiny a space - all the bulk of the amplifier was in the power supply, the heatsinks, and the smoothing capacitors surrounding the amp chip. Spreading the working bits around the place is asking for trouble - squash everything in tight, and then get rid of heat as efficiently as possible.
Speedskater
Major Contributor
The virtue of a big permanently installed isolation transformer, is that it can be wired as a 'separately derived system'. This means that the Safety Ground/Protective Earth path to the Neutral is short and low impedance. So the noise/interference currents don't need to go all the way back to the main breaker panel to get to their voltage source.
You can see the ground plane spreading out above and below the chip; that is the main thermal conduction path. At 90 % efficiency and 2x50 W then the package dissipates about 10 W, but only at full power, so they get away without a heat sink. Average power dissipation is probably under a Watt. I'd probably add one but there may be a sink on the back I am not seeing (part of the board mounting system), and/or I may be overly conservative (flight hardware has to work and we built in pretty good margin). The regulators on our boards are switchers, can (and do) drive 10 - 30 A at around 1 V continuously, and require no heat sinks but do depend upon the ground pour (plane) to help dissipate heat.
Tx = transformer? Highly variable, natch, but 40 dB is pretty achievable, then the circuits themselves add another 60 dB or so of rejection. The catch is that the transformer probably has sufficient bandwidth to pass some line distortion and it does not know any better (signal is signal, no feedback loop for error compensation in most transformers). I have measured 20 dB or less across some transformers, sometimes essentially none (0 dB) for LF noise, whereas something like a SOLA (self-resonant circuit that helps reject harmonics) can push 60 dB. In most cases the real rejection is from the power supply after the transformer, which yields 40 to 60 dB pretty easily. On a 100 V rail (e.g. a power amp) a signal 60 dB down is 100 mV, which would be a pretty noisy low-level signal but add another 40 dB of rejection and you're at 1 mV so power noise to the speaker is around 100 dB down. I don't think that's atypical. Regulated low-voltage supplies do even (much) better, of course. Where rejection typically falls short is in sustaining high-level signals of long duration from the power amplifiers, and you must include good high-frequency decoupling to filter out RF noise that can blow through the transformer.
Based on foggy memories of days gone by... - Don
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So, iv had to take out my balanced TX due to issues with tinting or ringing from my amplifiers and go back to bog standard mains..
I'm thinking of putting a isolation TX (5kv) in its stead, the company who make them also offer this(see picture bellow) . Any suggestions or musings as to just what it does? They put them on their balanced TX but I'm needing a regular TX so might ask them to install this device in one of the regulars isolation transformers .
Maybe a few questions I should ask or a spec I should inquire about? Any contributions will be appreciated
I'm thinking of putting a isolation TX (5kv) in its stead, the company who make them also offer this(see picture bellow) . Any suggestions or musings as to just what it does? They put them on their balanced TX but I'm needing a regular TX so might ask them to install this device in one of the regulars isolation transformers .
Maybe a few questions I should ask or a spec I should inquire about? Any contributions will be appreciated
watchnerd
Grand Contributor
Wow, life would be so much easier if room acoustics sorted themselves out by ignoring them!
watchnerd
Grand Contributor
Half of a Krell Master Reference Amplifier (monoblock) Output Channel board:
The Heat Sink would bolt on top of that.
Driver:
Road Testing:
It's like a steam locomotive.
Big. Manly. Lots of metal. Obsolete.
Which is what happens when the SQ is good enough - the mind does the sorting out then ... lets say you invite someone, highly proficient, to play acoustic guitar in your home - do you run around madly beforehand, re-organising the room, doing measurements galore, to make sure the room is a "perfect" listening environment - otherwise, your ability to enjoy the event will be severely impeded?
Yea but not balanced as that does weird things to my amps..
Sheesh. I thought I was away from the balanced section.
http://www.airlinktransformers.com/...sed_isolating_industrial_transformers/WM5002/
That but with the filter board I posted...they don't make one with the filters but they will if I ask.. I wanted to know if it will increase performance, or at least what it will do in terms of the electrical supply.
Are there any down sides to using it, theoretical or practical.
Amateur eyeball:
It appears to have devices on it to do two things:
Overvoltage protection - blue and black varistors on the left
High Frequency noise attenuation - copper chokes and gray bypass capacitors (if that's what they are). Chokes wound for common-mode noise rejection between L and N.
Plastic box at the top and little circuit at the top - don't know. Maybe a shut-off relay.
Black varistor - can't see how it is wired.
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I think the black thing is a thermistor, not a varistor. They are often used to control surges; they are high(er) resistance when cold, then as current flows through them they heat up and their resistance decreases. (You can buy them with the opposite tempco but that is for a different application.) Helps prevent large in-rush current (turn-on surges). The bad thing about them is that, since they are thermal, a short power glitch is not controlled if it is shorter than it takes for the thermistor to cool down ("reset").
The circuit on top has "9V IN" with some components then a relay. The relay appears to be in series with the "MAINS IN". Looks like a remote turn-on/off (trigger) circuit to me. I cannot tell if it is to shunt the thermistor (which could reduce the series resistance and take the heat off the thermistor).
Other than that, my guess matches RayDunzl's; looks like a noise filter.
Things to check include the current capacity (best to operate inductors, especially iron-core types, well below their maximum rating as they produce very ugly waveforms when those limits are exceeded) and the filter's bandwidth for voltage and current.
The circuit on top has "9V IN" with some components then a relay. The relay appears to be in series with the "MAINS IN". Looks like a remote turn-on/off (trigger) circuit to me. I cannot tell if it is to shunt the thermistor (which could reduce the series resistance and take the heat off the thermistor).
Other than that, my guess matches RayDunzl's; looks like a noise filter.
Things to check include the current capacity (best to operate inductors, especially iron-core types, well below their maximum rating as they produce very ugly waveforms when those limits are exceeded) and the filter's bandwidth for voltage and current.
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Thanks the big black thing is a thermistor.. It's a current in rush limiter for when the transformer is switched on. Thanks for your help
I wouldn't use that Thomas. Those MOVs (blue components) must be fused and have some kind of containment around them. The way they work is that the create a short when their voltage is reached. That voltage is above nominal mains voltage. That is fine except that the voltage keeps going down every time the get hit. Over time this can go low enough to become equiv. to mains voltage. At that point, they become a dead short and blow up catastrophically. The shrapnel can then cause secondary shorts elsewhere.
The proper design calls for fuses in line with each MOV. Without it, this is what happens in milder situations:
On positive side notice the cages around the MOVs on the left.
And this when everything hits the fan:
Here is an example of a better designed product with (wire) fuses:
On filtering your equipment has similar design internally so you would not notice any difference.
The proper design calls for fuses in line with each MOV. Without it, this is what happens in milder situations:
On positive side notice the cages around the MOVs on the left.
And this when everything hits the fan:
Here is an example of a better designed product with (wire) fuses:
On filtering your equipment has similar design internally so you would not notice any difference.
Knowing my luck it would all catch fire
What about a plain isolation TX? Any gain hardwiring one in between my circuit breaker and wall outlet?
What about a plain isolation TX? Any gain hardwiring one in between my circuit breaker and wall outlet?
Some varistors are internally fused...
http://www.littelfuse.com/~/media/e...stors_in_spd_and_ac_line_application_note.pdf
http://www.littelfuse.com/~/media/e...stors_in_spd_and_ac_line_application_note.pdf
Thanks ray, I will inquire when Airlink come back from Christmas shut down
I'd be interested to know why your amps don't like balanced power...
