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#1
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1.5 kva transformer
I'm having a lot of trouble finding the transformer I think I need on the
internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#2
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1.5 kva transformer
Dave Ryman wrote:
Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. |
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#3
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1.5 kva transformer
Dave Ryman wrote:
Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. |
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#4
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1.5 kva transformer
Dave Ryman wrote:
Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. |
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#5
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1.5 kva transformer
henryf wrote in news:46tzb.2795$Qd6.2117
@newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#6
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1.5 kva transformer
henryf wrote in news:46tzb.2795$Qd6.2117
@newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#7
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1.5 kva transformer
henryf wrote in news:46tzb.2795$Qd6.2117
@newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#8
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1.5 kva transformer
Dave Ryman wrote in
. 4: henryf wrote in news:46tzb.2795$Qd6.2117 @newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#9
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1.5 kva transformer
Dave Ryman wrote in
. 4: henryf wrote in news:46tzb.2795$Qd6.2117 @newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#10
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1.5 kva transformer
Dave Ryman wrote in
. 4: henryf wrote in news:46tzb.2795$Qd6.2117 @newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#11
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1.5 kva transformer
On 3 Dec 2003 18:47:32 GMT, Dave Ryman
wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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#12
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1.5 kva transformer
On 3 Dec 2003 18:47:32 GMT, Dave Ryman
wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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#13
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1.5 kva transformer
On 3 Dec 2003 18:47:32 GMT, Dave Ryman
wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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#14
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1.5 kva transformer
Dave Ryman wrote:
Dave Ryman wrote in . 4: henryf wrote in news:46tzb.2795$Qd6.2117 : Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. Check this out: http://www.toroid.com/standard_trans...amplifiers.htm |
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#15
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1.5 kva transformer
Dave Ryman wrote:
Dave Ryman wrote in . 4: henryf wrote in news:46tzb.2795$Qd6.2117 : Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. Check this out: http://www.toroid.com/standard_trans...amplifiers.htm |
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#16
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1.5 kva transformer
Dave Ryman wrote:
Dave Ryman wrote in . 4: henryf wrote in news:46tzb.2795$Qd6.2117 : Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. Check this out: http://www.toroid.com/standard_trans...amplifiers.htm |
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#18
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1.5 kva transformer
(Stewart Pinkerton) wrote in
: On 3 Dec 2003 18:47:32 GMT, Dave Ryman wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! Oh goody! Thanks v.much. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#19
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1.5 kva transformer
(Stewart Pinkerton) wrote in
: On 3 Dec 2003 18:47:32 GMT, Dave Ryman wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! Oh goody! Thanks v.much. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#20
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1.5 kva transformer
henryf wrote in
ink.net: http://www.toroid.com/standard_trans...nsformers/soli d_state_amplifiers.htm Thanks v.much for the link - greatly appreciated. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#21
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1.5 kva transformer
henryf wrote in
ink.net: http://www.toroid.com/standard_trans...nsformers/soli d_state_amplifiers.htm Thanks v.much for the link - greatly appreciated. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#22
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1.5 kva transformer
henryf wrote in
ink.net: http://www.toroid.com/standard_trans...nsformers/soli d_state_amplifiers.htm Thanks v.much for the link - greatly appreciated. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#23
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1.5 kva transformer
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#24
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1.5 kva transformer
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#26
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1.5 kva transformer
"Dave Ryman" wrote in message .4... I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one are you building a stadium amplifier system? |
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#27
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1.5 kva transformer
"Dave Ryman" wrote in message .4... I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one are you building a stadium amplifier system? |
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#28
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1.5 kva transformer
"Dave Ryman" wrote in message .4... I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one are you building a stadium amplifier system? |
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#29
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1.5 kva transformer
In article 32yAb.451954$Fm2.447256@attbi_s04, "malcolm" wrote:
"Dave Ryman" wrote in message . 1.4... I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one are you building a stadium amplifier system? I was interested in stadium power requirments. Maybe 25 to 75 KW. greg |
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#30
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1.5 kva transformer
In article 32yAb.451954$Fm2.447256@attbi_s04, "malcolm" wrote:
"Dave Ryman" wrote in message . 1.4... I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one are you building a stadium amplifier system? I was interested in stadium power requirments. Maybe 25 to 75 KW. greg |
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#31
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1.5 kva transformer
In article 32yAb.451954$Fm2.447256@attbi_s04, "malcolm" wrote:
"Dave Ryman" wrote in message . 1.4... I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. -- Thanks, Dave http://welcome.to/daves.website http://travel.to/formula.one are you building a stadium amplifier system? I was interested in stadium power requirments. Maybe 25 to 75 KW. greg |
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#32
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1.5 kva transformer
"Dave Ryman" wrote in message .4... Dave Ryman wrote in . 4: henryf wrote in news:46tzb.2795$Qd6.2117 @newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one plenty of toroidal transformers availible, try http://www.partsexpress.com/pe/showd...St=2352&St2=-5 4511875&St3=-80298645&DS_ID=3&Product_ID=123271&DID=7 http://www.partsexpress.com/pdf/avelspecs.pdf 500VA twin primarys of 0-110 Vac and twin secondarys of 0-25 Vac you will get 35-0-35 Vdc from the output if using full bridge rectification, and then have plenty of headroom to regulate down to 23.5 Vdc. Parts Express in the USA are good and quick from what I have found, and Maplin, Rapid, RS, Farnell in the UK. regards malcolm |
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#33
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1.5 kva transformer
"Dave Ryman" wrote in message .4... Dave Ryman wrote in . 4: henryf wrote in news:46tzb.2795$Qd6.2117 @newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one plenty of toroidal transformers availible, try http://www.partsexpress.com/pe/showd...St=2352&St2=-5 4511875&St3=-80298645&DS_ID=3&Product_ID=123271&DID=7 http://www.partsexpress.com/pdf/avelspecs.pdf 500VA twin primarys of 0-110 Vac and twin secondarys of 0-25 Vac you will get 35-0-35 Vdc from the output if using full bridge rectification, and then have plenty of headroom to regulate down to 23.5 Vdc. Parts Express in the USA are good and quick from what I have found, and Maplin, Rapid, RS, Farnell in the UK. regards malcolm |
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#34
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1.5 kva transformer
"Dave Ryman" wrote in message .4... Dave Ryman wrote in . 4: henryf wrote in news:46tzb.2795$Qd6.2117 @newsread1.news.atl.earthlink.net: Dave Ryman wrote: Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Your amplifiers want DC power, not AC, so directly connecting them to transformers won't work. I was intended to include rectifiers and voltage regulators, too! I've revised my figures after reading http://www.dckits.com/app1.htm I'm going to used a max voltage of +23.5 and -23.5 vdc. I am assuming that a 50w output will consume no more than 75w (1.5*50). Therefore, each amplifier will be protected by 2A fuses (not 5A as previously imagined). Supplying a pd of 47v at 5x1.6A gives me a transformer requirement of 376VA in total: Still a tall order given the range of transformers normally available. I am therefore considering five separate transformers of 100va capacity each, these should be more easily available - hopefully cheaper. I may even go for separate boxes for each amp, and work it round a modular basis. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one plenty of toroidal transformers availible, try http://www.partsexpress.com/pe/showd...St=2352&St2=-5 4511875&St3=-80298645&DS_ID=3&Product_ID=123271&DID=7 http://www.partsexpress.com/pdf/avelspecs.pdf 500VA twin primarys of 0-110 Vac and twin secondarys of 0-25 Vac you will get 35-0-35 Vdc from the output if using full bridge rectification, and then have plenty of headroom to regulate down to 23.5 Vdc. Parts Express in the USA are good and quick from what I have found, and Maplin, Rapid, RS, Farnell in the UK. regards malcolm |
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#35
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1.5 kva transformer
"gregs" wrote in message t... In article , (Stewart Pinkerton) wrote: On 3 Dec 2003 18:47:32 GMT, Dave Ryman wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! I guess he wants 240 input. If anybody needs a torroid transformer core of 15 lbs, for 120vac, probably good for 1200 to 1800 watts, let me know. I got it out of a variac some time ago planning on doing a home brew, but I don't plan on doing that now. Got too many amps as it is. Its relatively easy to wind secondaries on top of the core. greg NOT SHORTED ONES  |
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#36
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1.5 kva transformer
"gregs" wrote in message t... In article , (Stewart Pinkerton) wrote: On 3 Dec 2003 18:47:32 GMT, Dave Ryman wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! I guess he wants 240 input. If anybody needs a torroid transformer core of 15 lbs, for 120vac, probably good for 1200 to 1800 watts, let me know. I got it out of a variac some time ago planning on doing a home brew, but I don't plan on doing that now. Got too many amps as it is. Its relatively easy to wind secondaries on top of the core. greg NOT SHORTED ONES |
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#37
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1.5 kva transformer
"gregs" wrote in message t... In article , (Stewart Pinkerton) wrote: On 3 Dec 2003 18:47:32 GMT, Dave Ryman wrote: I'm having a lot of trouble finding the transformer I think I need on the internet, or instructions for building one from a kit. First, I BELIEVE I need a 1.5 kva transformer (or in that ballpark). Each amplifier circuit I'm building wants +30v, 0v and -30v (60v transformer with centre tap). Each circuit is to be protected by a 5A fuse. There are to be five such circuits running from one supply. I am therefore assuming that I need a step-down transformer to provide 60v from a 240v supply, and that this needs to be rated at 1.5kva. I may have my sums wrong - please correct me if I do! I could conceivably use 5 300va transformers, but these seem just as hard to find. What can I do? Any advice warmly appreciated. Building your system as five monobloc amps with independent 250-300VA trannies will give excellent results - and lots of audiophile 'street cred'! I guess he wants 240 input. If anybody needs a torroid transformer core of 15 lbs, for 120vac, probably good for 1200 to 1800 watts, let me know. I got it out of a variac some time ago planning on doing a home brew, but I don't plan on doing that now. Got too many amps as it is. Its relatively easy to wind secondaries on top of the core. greg NOT SHORTED ONES |
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#38
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1.5 kva transformer
"malcolm" wrote in
news:VdyAb.251651$Dw6.871099@attbi_s02: (snip) http://welcome.to/daves.website http://travel.to/formula.one plenty of toroidal transformers availible, try http://www.partsexpress.com/pe/showd...3842&St=2352&S t2=-5 4511875&St3=-80298645&DS_ID=3&Product_ID=123271&DID=7 http://www.partsexpress.com/pdf/avelspecs.pdf 500VA twin primarys of 0-110 Vac and twin secondarys of 0-25 Vac you will get 35-0-35 Vdc from the output if using full bridge rectification, and then have plenty of headroom to regulate down to 23.5 Vdc. Parts Express in the USA are good and quick from what I have found, and Maplin, Rapid, RS, Farnell in the UK. regards malcolm Found a 25v transformer on RS - I'm switching my allegence from Maplin - RS seem to have a better range available. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#39
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1.5 kva transformer
"malcolm" wrote in
news:VdyAb.251651$Dw6.871099@attbi_s02: (snip) http://welcome.to/daves.website http://travel.to/formula.one plenty of toroidal transformers availible, try http://www.partsexpress.com/pe/showd...3842&St=2352&S t2=-5 4511875&St3=-80298645&DS_ID=3&Product_ID=123271&DID=7 http://www.partsexpress.com/pdf/avelspecs.pdf 500VA twin primarys of 0-110 Vac and twin secondarys of 0-25 Vac you will get 35-0-35 Vdc from the output if using full bridge rectification, and then have plenty of headroom to regulate down to 23.5 Vdc. Parts Express in the USA are good and quick from what I have found, and Maplin, Rapid, RS, Farnell in the UK. regards malcolm Found a 25v transformer on RS - I'm switching my allegence from Maplin - RS seem to have a better range available. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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#40
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1.5 kva transformer
"malcolm" wrote in
news:VdyAb.251651$Dw6.871099@attbi_s02: (snip) http://welcome.to/daves.website http://travel.to/formula.one plenty of toroidal transformers availible, try http://www.partsexpress.com/pe/showd...3842&St=2352&S t2=-5 4511875&St3=-80298645&DS_ID=3&Product_ID=123271&DID=7 http://www.partsexpress.com/pdf/avelspecs.pdf 500VA twin primarys of 0-110 Vac and twin secondarys of 0-25 Vac you will get 35-0-35 Vdc from the output if using full bridge rectification, and then have plenty of headroom to regulate down to 23.5 Vdc. Parts Express in the USA are good and quick from what I have found, and Maplin, Rapid, RS, Farnell in the UK. regards malcolm Found a 25v transformer on RS - I'm switching my allegence from Maplin - RS seem to have a better range available. -- Regards, Dave http://welcome.to/daves.website http://travel.to/formula.one |
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