82r and 100/120Vac are not compatible.
I repeat how I arrive at the required added resistance.
power = 800VA
Mains = 115Vac
Current at maximum operating power = 800/115 = 6.96Aac
Fit a close rated fuse of 6.96A, or slightly less. Use a 6.15A slow blow fuse.
This fuse can pass a short term peak of double it's rating and do so repeatedly over a few years of operation. That brings us to a 12.3A maximum start up current.
Using 115Vac and 12.3Aac of current you need a total resistance of 115/12.3 = 9.35ohms.
Subtract the primary resistance from that total and you arrive at an added resistance of ~8.5ohms to 9ohms
Power resistors totalling 8r8 could be formed from 4 off 5W 2r2 ceramic cased wirewound radial. Or use a 10ohms Power Thermistor.
82r of added resistance would be suitable for soft starting a 60VA 115Vac transformer fitted with a 500mA slow blow fuse.
I repeat how I arrive at the required added resistance.
power = 800VA
Mains = 115Vac
Current at maximum operating power = 800/115 = 6.96Aac
Fit a close rated fuse of 6.96A, or slightly less. Use a 6.15A slow blow fuse.
This fuse can pass a short term peak of double it's rating and do so repeatedly over a few years of operation. That brings us to a 12.3A maximum start up current.
Using 115Vac and 12.3Aac of current you need a total resistance of 115/12.3 = 9.35ohms.
Subtract the primary resistance from that total and you arrive at an added resistance of ~8.5ohms to 9ohms
Power resistors totalling 8r8 could be formed from 4 off 5W 2r2 ceramic cased wirewound radial. Or use a 10ohms Power Thermistor.
82r of added resistance would be suitable for soft starting a 60VA 115Vac transformer fitted with a 500mA slow blow fuse.
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If the switch is allowing/blocking the live voltage to the board, why do you need to run from mains to board, to switch, back to board? Couldn't you just run mains to switch, to board? I guess I'm not understanding this layout. It seems like, the way it is in the diagram, that you're not actually switching the live, that it's always going to that board, with only that tiny little cap in the way. What am I missing? Apologies for my naivete.
Yes, but can it carry a tune?
With a mains now uncoupled from the neutral and running by itself to/from the switch, couldn't that cause hum issues?
One other really dumb question. With the keystone connectors, do you just put the wires under and crimp them down to the board or are you supposed to attach the wires to a ring terminal and clamp that between the block and the set-screw on the connector? I always see pics of the board populated but never any good ones with wires connected. Surely 6L6 has action shots of the wires and how they should be corrected, no?
With a mains now uncoupled from the neutral and running by itself to/from the switch, couldn't that cause hum issues?
One other really dumb question. With the keystone connectors, do you just put the wires under and crimp them down to the board or are you supposed to attach the wires to a ring terminal and clamp that between the block and the set-screw on the connector? I always see pics of the board populated but never any good ones with wires connected. Surely 6L6 has action shots of the wires and how they should be corrected, no?
Nothing with wire, but here are the action shots - (post #54 of this thread)
http://www.diyaudio.com/forums/diya...supply-soft-start-board-v3-2.html#post3832887
I used a ring terminal to connect to the screws.
Yes, I seem to remember him pointing that out a few times.
Any reason not to twist the power leads to/from the switch?Regarding the keystone... maybe that's why I can never find pics of how to use the darn things, no one can come to a consensus!
Two core mains cable is double insulated.
The two cores are close couple but not twisted.
The outer insulation prevents twisting of the cores.
Three core mains cable is also double insulated. But here the three cores are usually twisted.
If you were to use adequately insulated single core cable and twist the two wires, then you could have a twisted mains cable. but you are only allowed to use this internally where users have no access.
I usually do this twisting of mains single cores and add on the double insulation so that I am protected while the equipment is powered on with the cover off to enable measurements.
The two cores are close couple but not twisted.
The outer insulation prevents twisting of the cores.
Three core mains cable is also double insulated. But here the three cores are usually twisted.
If you were to use adequately insulated single core cable and twist the two wires, then you could have a twisted mains cable. but you are only allowed to use this internally where users have no access.
I usually do this twisting of mains single cores and add on the double insulation so that I am protected while the equipment is powered on with the cover off to enable measurements.
In the first half, are you speaking about the mains cable that plugs into the IEC jack on the back of the amp?
In the second half, regarding double insulation, what is adequate? Just heat-shrink over the twisted cables (insulated wire itself, to and from the switch).
I know you're trying to be helpful and I appreciate anyone's advice who cares to answer my questions, but your post reads like a riddle and I'm not sure I'm understanding what you're trying to get across.
In the second half, regarding double insulation, what is adequate? Just heat-shrink over the twisted cables (insulated wire itself, to and from the switch).
I know you're trying to be helpful and I appreciate anyone's advice who cares to answer my questions, but your post reads like a riddle and I'm not sure I'm understanding what you're trying to get across.
You asked this question
I am only referring to the internal cabling inside the enclosure, in direct response to your question.
There is mains cable taking current to the transformer and possibly some other components (switch, fuse etc.)
This mains cable can be a two core cable. It is better to twist it.
But as stated in post218
I replied with why twisting is not easy/possible.
I am only referring to the internal cabling inside the enclosure, in direct response to your question.
There is mains cable taking current to the transformer and possibly some other components (switch, fuse etc.)
This mains cable can be a two core cable. It is better to twist it.
But as stated in post218
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