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#1
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In article ,
Richard Harrison wrote: Off topic, but you can`t power an antenna without power to the transmitter. I`m looking for a d-c to d-c converter that takes 28 volts on the input and supplies 12 volts on the output. Up to 8 amperes may regularly be drawn from the supply. That`s about 100 watts. I need it now. That`s why I`m imposing on this group. There is no more knowledgeable group to ask that I know of. I don`t have time to build anything, though I`ve built such inverters and converters. Check with Vicor (www.vicr.com). They make a whole range of DC-to-DC converter modules. Example: their V24B12C200B converter module takes 18-36 volts in, 12 volts out (programmable from 10% to 11% of this, so you could get 13.2 out), efficiency 85%, 200 watts output. Current limit is 17 amps minimum, 19.2 amps typical. They do have a 100-watt module, but I suspect you'd be running it right at the ragged edge of its specs. There are other manufacturers playing in this market space... Datel is one. A simple voltage divider or regulator is too lossy for high utilization. I need lossless resistance. You won't get 100% efficiency out of anything like this. 80-90% seems to be achievable with commercial products. I would like rugged, reliable, efficient, replaceable, and cheap. I think you can get the first four if you look around. The fifth is likely to be the hardest, if you want the first four. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#2
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"Dave Platt" wrote in message ... In article , Richard Harrison wrote: Off topic, but you can`t power an antenna without power to the transmitter. I`m looking for a d-c to d-c converter that takes 28 volts on the input and supplies 12 volts on the output. Up to 8 amperes may regularly be drawn from the supply. That`s about 100 watts. I need it now. That`s why I`m imposing on this group. There is no more knowledgeable group to ask that I know of. I don`t have time to build anything, though I`ve built such inverters and converters. Check with Vicor (www.vicr.com). They make a whole range of DC-to-DC converter modules. Example: their V24B12C200B converter module takes 18-36 volts in, 12 volts out (programmable from 10% to 11% of this, so you could get 13.2 out), efficiency 85%, 200 watts output. Current limit is 17 amps minimum, 19.2 amps typical. I suspect, since 'up to 8 amperes may be drawn', that he'll have a hard time meeting the '17 amps minimum' spec... __ Steve KI5YG .. |
#3
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In article om,
Stephen Cowell wrote: Example: their V24B12C200B converter module takes 18-36 volts in, 12 volts out (programmable from 10% to 11% of this, so you could get 13.2 out), efficiency 85%, 200 watts output. Current limit is 17 amps minimum, 19.2 amps typical. I suspect, since 'up to 8 amperes may be drawn', that he'll have a hard time meeting the '17 amps minimum' spec... Sorry, I was unclear. What the phraseology means is "The converter's maximum current output is limited to a value which might, in some cases, be as low as 17 amperes, but is typically around 19.2 amperes." I didn't mean to imply that you _must_ draw 17 amperes from the converter in order for it to work. There doesn't appear to be a significant lower limit - load reguulation is given as 0.2% typical "no load to full load, nominal input" as long as you haven't trimmed the converter to a lower output voltage. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#4
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Sorry, I was unclear. What the phraseology means is "The converter's
maximum current output is limited to a value which might, in some cases, be as low as 17 amperes, but is typically around 19.2 amperes." I didn't mean to imply that you _must_ draw 17 amperes from the converter in order for it to work. There doesn't appear to be a significant lower limit - load reguulation is given as 0.2% typical "no load to full load, nominal input" as long as you haven't trimmed the converter to a lower output voltage. -- Dave Platt AE6EO Dave, Even though you may have been unclear, REAL radio amateurs knew exactly what you meant - ignore wise-ass comments from those trying to be a bit more clever than others - it illustrates various weaknesses ..... Nick |
#5
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"nick smith" wrote in message ... Sorry, I was unclear. What the phraseology means is "The converter's maximum current output is limited to a value which might, in some cases, be as low as 17 amperes, but is typically around 19.2 amperes." I didn't mean to imply that you _must_ draw 17 amperes from the converter in order for it to work. There doesn't appear to be a significant lower limit - load reguulation is given as 0.2% typical "no load to full load, nominal input" as long as you haven't trimmed the converter to a lower output voltage. -- Dave Platt AE6EO Dave, Even though you may have been unclear, REAL radio amateurs knew exactly what you meant - ignore wise-ass comments from those trying to be a bit more clever than others - it illustrates various weaknesses ..... Hey Nick... chupe' mis huevos. It was *not* clear, and Dave knew it, and copped to it. __ Steve KI5YG .. |
#6
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Steve wrote:
"Chupe` mis huevos." During the "Tio Paco" (Franco) era in Spain, the story goes that the Madrid newspaper printed the picture of a single egg on the front page. Underneath was printed: "Donde esta el otro?" Franco`s officials didn`t think it funny and levied heavy penalties on the paper and everyone concerned. Best regards, Richard Harrison, KB5WZI |
#7
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"Richard Harrison" wrote in message ... Steve wrote: "Chupe` mis huevos." During the "Tio Paco" (Franco) era in Spain, the story goes that the Madrid newspaper printed the picture of a single egg on the front page. Underneath was printed: "Donde esta el otro?" Franco`s officials didn`t think it funny and levied heavy penalties on the paper and everyone concerned. Oh, was Franco like Hitler in that regard, as well? __ Steve KI5YG .. |
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