What Is The diyAudio Forums purpose
This forms existance is for the exchange of information between people with common interests. If this forum did not exist I would not have been able to make the class of amplifier that I have done, yes I have made the current work I am doing on the Aleph J-X public in this Forum, mostly the choice of components because the working of the amplifiers circuits are explained in detail in Nelson Pass's Projects, and other assembly papers created by hobiest like Grey and others, you know all of this, so why would you say I should not be communicating in this Forum, when I am currently its largest contributer of comunication directly related to the building of two Aleph J-X mono amps.
Getting back to the fuse problem, is it posible that my amps are drawing over 30amps when started with a 750VA transformer, or is it actually 18volts X 41.67amps equals 750VA, could I be getting a surge of 41.67amps ?
Thank You For Your Help
Ian
This forms existance is for the exchange of information between people with common interests. If this forum did not exist I would not have been able to make the class of amplifier that I have done, yes I have made the current work I am doing on the Aleph J-X public in this Forum, mostly the choice of components because the working of the amplifiers circuits are explained in detail in Nelson Pass's Projects, and other assembly papers created by hobiest like Grey and others, you know all of this, so why would you say I should not be communicating in this Forum, when I am currently its largest contributer of comunication directly related to the building of two Aleph J-X mono amps.
Getting back to the fuse problem, is it posible that my amps are drawing over 30amps when started with a 750VA transformer, or is it actually 18volts X 41.67amps equals 750VA, could I be getting a surge of 41.67amps ?
Thank You For Your Help
Ian
SCAIFF001:
You're welcome in the forum. We just don't want you diluting *this* thread with information that *isn't relevant to the Aleph J-X*. Nobody else here needs to read about sizing PSU fuses because we all would have known well before we attempted this amp.
I just ask that you open a thread of your own. Also there is a seperate forum in fact for power supply issues.
You're welcome in the forum. We just don't want you diluting *this* thread with information that *isn't relevant to the Aleph J-X*. Nobody else here needs to read about sizing PSU fuses because we all would have known well before we attempted this amp.
I just ask that you open a thread of your own. Also there is a seperate forum in fact for power supply issues.
these general psu queries have been covered many times, I would suggest even before starting a thread in the PSU forum that you use the search function to search for similar threads and solutions. the basic issues under discussion are not specific to this amp and too much space has been devoted to it in this thread.
I'm not telling you to **** off in general =) it just gets a little frustrating when I get continual email updates for off topic posts in the thread (just as this post is). your build appears to be pretty epic so I would like you to succeed and see build pics, but please keep the posts in here limited to AJ/AJX related inquiries.
I would recommend checking out Duncans PSUD psu calculator, modelling software and spice. I gather your PSU is total overkill as far as caps, provided you dont have a short, perhaps the inrush current is tripping your fuse and you should look into a soft start, otherwise you may need to size the fuse too large and it will not be useful under fault conditions. You could also place additional inline fuses in the DC lines, or on the secondary AC side. Adjust these secondary side fuses after you work out what the normal peak operating current of the amp is in your system.
I would also recommend you test out the PSU with the amp disconnected and if you have one, at least initially troubleshoot with a lower voltage, lower power transformer, a variac would be ideal. build yourself a bulb tester too,
I'm not telling you to **** off in general =) it just gets a little frustrating when I get continual email updates for off topic posts in the thread (just as this post is). your build appears to be pretty epic so I would like you to succeed and see build pics, but please keep the posts in here limited to AJ/AJX related inquiries.
I would recommend checking out Duncans PSUD psu calculator, modelling software and spice. I gather your PSU is total overkill as far as caps, provided you dont have a short, perhaps the inrush current is tripping your fuse and you should look into a soft start, otherwise you may need to size the fuse too large and it will not be useful under fault conditions. You could also place additional inline fuses in the DC lines, or on the secondary AC side. Adjust these secondary side fuses after you work out what the normal peak operating current of the amp is in your system.
I would also recommend you test out the PSU with the amp disconnected and if you have one, at least initially troubleshoot with a lower voltage, lower power transformer, a variac would be ideal. build yourself a bulb tester too,
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start up current
Hi,
Thank you for the communication, I need it even though we are all aware of what you have said, it migt seem to uncomplicated for some people, but being a professional scientist I am all to aware that the uncomplicated looking problems are easy to fix when looking at them from outside, scientists are capable of making the stupidest errors in calculations and unable to see the errors no matter how many times they have reviewed them, that is why we have research teams, without this forum I stand alone and unable to pass through the small details while thinking of the whole picture.
I have made an error when communicating my power supply components, I have a 600VA transformer not a 750VA, I have been useing a Nelson Pass A75 Part2 project schematic for a model of my power supply and it has a 750VA transformer, so a 30amp slow blow fuse should be logical, because 18volts by 33.33amps equals 600VA, the manufacure states that the lagest current it will output is 31.6amps(see attachment "Antek AN-6218" parallel coils test specifications for this current of 31.6amps at 17.9volts). This current of 31.6amps is not what I have been naturally calculating with, but insted I have been useing 8.3amps at 18volts as also stated by the manufacturer at the following site:
Antek - AN-6218
Sorry for talking so much about an easy calculation that should have been performed early in the project, and everything I talk about here is the Aleph J-X amplifier I am constructing, I have way over $2,000.00 invested so far in my components for two mono amps.
Hi,
Thank you for the communication, I need it even though we are all aware of what you have said, it migt seem to uncomplicated for some people, but being a professional scientist I am all to aware that the uncomplicated looking problems are easy to fix when looking at them from outside, scientists are capable of making the stupidest errors in calculations and unable to see the errors no matter how many times they have reviewed them, that is why we have research teams, without this forum I stand alone and unable to pass through the small details while thinking of the whole picture.
I have made an error when communicating my power supply components, I have a 600VA transformer not a 750VA, I have been useing a Nelson Pass A75 Part2 project schematic for a model of my power supply and it has a 750VA transformer, so a 30amp slow blow fuse should be logical, because 18volts by 33.33amps equals 600VA, the manufacure states that the lagest current it will output is 31.6amps(see attachment "Antek AN-6218" parallel coils test specifications for this current of 31.6amps at 17.9volts). This current of 31.6amps is not what I have been naturally calculating with, but insted I have been useing 8.3amps at 18volts as also stated by the manufacturer at the following site:
Antek - AN-6218
Sorry for talking so much about an easy calculation that should have been performed early in the project, and everything I talk about here is the Aleph J-X amplifier I am constructing, I have way over $2,000.00 invested so far in my components for two mono amps.
haha wow good catch, I didnt even register that, my brain assumed that he, like Antek was talking about secondary current rating. but honestly I didnt read it that closely, I was just trying to avoid this convo in here.
scaff, as i'm sure you are aware, the large current is on the secondary side, high voltage, lower current on the primary side, lower voltage, higher current on the secondary. 115vac at 30A is 3.45kVA (disregarding copper losses etc), what good is your fuse? the TX will be a molten puddle of copper and lead before it trips from over-current. the fact you are still popping it means short circuit, theres no way the fuse isnt big enough and no amount of inrush current is going to pop that sucker either =)
but, just to check that we arent talking about such a simple mistake, i'm baffled, are you actually blowing a fuse of that rating? where is it? on the rail or on the IEC? I would have thought the amp would vaporize before that happened, no magic blue smoke?
sorry I really dont have time for this though, i'm going to have to just leave you with it, good luck. after blowing that much on the amp and no small amount of it on the PSU, I would definitely try and get a variac, or start with a low voltage transformer and make up a bulb tester
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Picture of my 1of2 mono amp, not working yet
Hi,
I understand that peple want to see what my amps look like, I am having trouble making a photo that I can load into this forum, I have Photoshop but have not been able to make a smaller data size image without loss of to much detail or size, I am open to any ideas of how to create a better image for you.
Ian
Hi,
I understand that peple want to see what my amps look like, I am having trouble making a photo that I can load into this forum, I have Photoshop but have not been able to make a smaller data size image without loss of to much detail or size, I am open to any ideas of how to create a better image for you.
Ian
better pickture 1of2 mono Aleph J-X, not working yet
Hi everyone,
This is a clearer photo of my amp, I will try to creat many better photos, my amps have alot of AC processing before it gets to the transformer: 2 AC lines DC filter, soft start, thermal shutdown, 4 AC fan controlers, I ahve bypassed all of the AC line circuits untill I can get the amp working without them.
Thank You
Ian
Hi everyone,
This is a clearer photo of my amp, I will try to creat many better photos, my amps have alot of AC processing before it gets to the transformer: 2 AC lines DC filter, soft start, thermal shutdown, 4 AC fan controlers, I ahve bypassed all of the AC line circuits untill I can get the amp working without them.
Thank You
Ian
Attachments
fuse placement location
Hi,
I was not aware of putting the fuses after the cap bank, I was worried that I might blow the capacitors I am useing because they cost $45.00 each and I use 18 of them per mono Aleph J-X.
The output of my transformer tests ok so I will try this placeing of the fuses after the capacitor&coil bank.
Thank You
Ian
Hi,
I was not aware of putting the fuses after the cap bank, I was worried that I might blow the capacitors I am useing because they cost $45.00 each and I use 18 of them per mono Aleph J-X.
The output of my transformer tests ok so I will try this placeing of the fuses after the capacitor&coil bank.
Thank You
Ian
possible short circuit
Hi,
Your comments are usefull for me, the possible short circuit I thought I have avoided because of the layout of my amps(see photo on an other thred), I will test for this with a small power supply I have while isolating the capacitor-coil banks from the rest of the amplifier.
Thank You
Ian
Hi,
Your comments are usefull for me, the possible short circuit I thought I have avoided because of the layout of my amps(see photo on an other thred), I will test for this with a small power supply I have while isolating the capacitor-coil banks from the rest of the amplifier.
Thank You
Ian
mains breaker
Hi,
I am aware that some of the fuse values I have stated are a way out of wack, that is why I am talking to you now so that I dont make an expensive mistake by not properly thinking this problem I am having alone, I require everyones help for developing a step by step solution to the problem I have created.
Thank You
Ian
Hi,
I am aware that some of the fuse values I have stated are a way out of wack, that is why I am talking to you now so that I dont make an expensive mistake by not properly thinking this problem I am having alone, I require everyones help for developing a step by step solution to the problem I have created.
Thank You
Ian
power supply research
Hi,
I dont know what type of image I have created of myself, I am very well read on power supply design, and mine was designed using Spice , and component values are all taken from known operating class A amplifiers, that is why I have to get back to basic testing and analyses that has been encouraged to me in this forum.
Thank You For Your Input
Ian
Hi,
I dont know what type of image I have created of myself, I am very well read on power supply design, and mine was designed using Spice , and component values are all taken from known operating class A amplifiers, that is why I have to get back to basic testing and analyses that has been encouraged to me in this forum.
Thank You For Your Input
Ian
Aleph J-X amp layout options
I did not plan to assemble the amp like I did, the heat sinks I am using do not require any fans but I have used four of them just for the layout of the wood box, I will put the amp in a metal box when I have them working so I know prcisely what I am dealing with, then again I will probibly never build metal boxs once the amps are working properly because I have the 2 ballanced DA converters to build next, one for each channel to take advantage of the ballanced Aleph J-X .
Ian
Hi,
I did not plan to assemble the amp like I did, the heat sinks I am using do not require any fans but I have used four of them just for the layout of the wood box, I will put the amp in a metal box when I have them working so I know prcisely what I am dealing with, then again I will probibly never build metal boxs once the amps are working properly because I have the 2 ballanced DA converters to build next, one for each channel to take advantage of the ballanced Aleph J-X .
Ian
Well, you should really go to the beginning and test with the actual amp disconnected and only one cap as reservoir - and work from here.
To your original post - it is unclear to my why one would put fuses right after the bridges before the actual caps, as that is the high current highway. Uncharged caps are almost perfect shorts if only for milliseconds.
Fusing is done on the primary and usually combined with thermistors to handle inrush current and avoid tripping the main breaker. Some also fuse the rail from the caps to the actual amp to avoid killing the amp in case of a short at the output. However, I would certainly use a bleeder resistor for the caps in this case to ensure that the caps can sufficiently quickly discharge when the fuse blows. Also keep in mind that your speakers might not be happy with the signal they'll get when the fuse blows, so I would use them with caution.
Also, the standard fuses are not much of a practical use; they're more of a 'don't burn my house down' sort of safety feature.
if you read in detail about their ratings you will find that an 8 A fuse does not blow at 8.1A, but more like at 16 A after 10 seconds or so. In practice if used to close to their rating they will fail sometimes even if there was no overcurrent.
Finally, the transformer ratings are generally continous values with the internal heating used as limit. In practice they can give much larger currents for short whiles (as they typically do when recharging the caps), don't forget that the caps are only charged at the top of the rectified sine, so one can easily see 100A for a few milliseconds.
I would use thermistors+fuses for the primary and CRC filtering to get the inrush down if necessary.
I hope this helps a bit.
Hannes
PS: this is something more for the PSU forum, you would likely get also more response there.
fixed power supply problem, amp still not working
Hi everyone,
I am glasd to say that I have fixed the power supply problem, it was the stupidest mistake, now I have 26.4volts positive and negitive, when I connect it to the circuit boards it goes down to 21.6 volts positive and negitive, but the amplifier still dose not work.
I have a mp3 player hooked up to the input, when I turn on the power I hear nothing but when I turn the amplifier off I hear the music for two seconds, then nothing.
The voltage seems to be correct now but I cannot get any current reading on my volt multi-meter.
Dose anyone have any ideas on what might be my current problem ?
Thank You For Any Help
Ian
Hi everyone,
I am glasd to say that I have fixed the power supply problem, it was the stupidest mistake, now I have 26.4volts positive and negitive, when I connect it to the circuit boards it goes down to 21.6 volts positive and negitive, but the amplifier still dose not work.
I have a mp3 player hooked up to the input, when I turn on the power I hear nothing but when I turn the amplifier off I hear the music for two seconds, then nothing.
The voltage seems to be correct now but I cannot get any current reading on my volt multi-meter.
Dose anyone have any ideas on what might be my current problem ?
Thank You For Any Help
Ian