Hi, probably a really stupid question but are the led's in this circuit purely for indication purposes or do they serve another purpose. Also why would there be 1 green and one red, is it just to differentiate between + rail and - rail?
[url=https://flic.kr/p/2jq85jw]
s-l1600 by matt Franklin, on Flickr[/URL]
Thanks
Matt
[url=https://flic.kr/p/2jq85jw]
s-l1600 by matt Franklin, on Flickr[/URL]Thanks
Matt
LEDs are about as cheap as resistors now, so some use them liberally on pcbs,
if the extra current draw is not a problem. In a power amp, it wouldn't be.
if the extra current draw is not a problem. In a power amp, it wouldn't be.
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There are two independent secondaries, each with a FWB (full wave bridge) rectifier,
each circuit generating one DC voltage. Then the two output voltages are connected
in series, with the common connection "grounded" to form a bipolar supply.
If the two secondaries were connected in series to form a center tap, then only four diodes
would be needed to form a bipolar supply.
Bridge Rectifier Circuit - Design Details & Tips >> Electronics Notes
each circuit generating one DC voltage. Then the two output voltages are connected
in series, with the common connection "grounded" to form a bipolar supply.
If the two secondaries were connected in series to form a center tap, then only four diodes
would be needed to form a bipolar supply.
Bridge Rectifier Circuit - Design Details & Tips >> Electronics Notes
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Ah ok, is it just an example of more than one way to skin a cat or are there advantages to this particular design like higher current capabilities? This power supply is for one channel of le-monstre.
The two circuit types require different secondary voltages, to have the same output voltages.
If you have a single CT secondary, the decision is made. If you have two secondaries,
you could go either way if you have a choice of secondary voltages. For higher currents
I'd go with two secondaries and two FWB rectifiers. The two supply outputs would be connected
together at one point which is taken as the common. That one is the schematic that you have.
If you have a single CT secondary, the decision is made. If you have two secondaries,
you could go either way if you have a choice of secondary voltages. For higher currents
I'd go with two secondaries and two FWB rectifiers. The two supply outputs would be connected
together at one point which is taken as the common. That one is the schematic that you have.
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There can be some "upmarket reasons " although just one full-wave rectifier would do but this question was put on a professional electronics website forum (USA ) and one of the older "heavy hitters " wasn't so nice about it saying-
Yes, you could also use separate bridge rectifiers on each of the secondaries, and then wire the outputs into a dual rail, +15 and -15V output arrangement. There are some "audiophool" circuits that use that topology. They think that having MORE components somehow makes the circuit "better". Of course there is no merit in that fantasy, but audiophools are very stubborn and dislike facts.
The above aren't my words but a pretty sarcastic sounding guy with an obvious chip on his shoulder.
Yes, you could also use separate bridge rectifiers on each of the secondaries, and then wire the outputs into a dual rail, +15 and -15V output arrangement. There are some "audiophool" circuits that use that topology. They think that having MORE components somehow makes the circuit "better". Of course there is no merit in that fantasy, but audiophools are very stubborn and dislike facts.
The above aren't my words but a pretty sarcastic sounding guy with an obvious chip on his shoulder.
The "fool" circuits will usually have less hum and noise, since there's no center tap
with charging pulses going through it.
with charging pulses going through it.
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Looking at those diagrams then this particular supply is a resistive load? so I require a 230V 2 X 15V sec probably around 160-225VA. Or have I got that completely wrong?
Have to decide first how much output voltage, and how much DC load current, is required.
Seems the amp uses +/- 12VDC supplies. The 4A fuses would imply around an amp or so.
If you do want 12V supplies, the secondaries should be more like 10VAC each, but it depends.
The 15VAC secondaries would definitely be too high for an unregulated 12V supply like this.
Since this is same as the diyAudio power supply board, you could use that board.
Universal Power Supply – diyAudio Store
Seems the amp uses +/- 12VDC supplies. The 4A fuses would imply around an amp or so.
If you do want 12V supplies, the secondaries should be more like 10VAC each, but it depends.
The 15VAC secondaries would definitely be too high for an unregulated 12V supply like this.
Since this is same as the diyAudio power supply board, you could use that board.
Universal Power Supply – diyAudio Store
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@ the old time heavy hitters of the other website. If we were only concerned with what would do the job there would no need for this forum! We would all simply buy the first hi-fi we saw as they all do the same job! Hell lots of people would argue there is simply no need for so many large Capacitors in this type of circuit but I and many other people bought them anyway.
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Yes Two different color LEDs are good for debug - tell which rail or circuit consumer is under stress.
In my case, one blew up as soon as I switched on, sometimes. This helped.
In my case, one blew up as soon as I switched on, sometimes. This helped.
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As a tech, I see no real reason to design such a complicated supply.
Besides, either way, the grounds come to a common point.
And I've never come across a properly designed "common ground" PS that had hum or noise.
But, some like to nitpick themselves to death over the complexity and alleged benefits of such things.
I think there's only one diyAudio power supply board. It has two independent FWB supplies on it, like your schematic.
Not sure how you could use 15VAC secondaries for the amplifier that needs 12VDC supplies.
Adding regulators to the supply outputs could drop the voltages, but that would dissipate some power.
Depends on the current draw of the amplifier what you could do.