averaging maybe once a hour, the AC line voltage sags in my house enough to make the lights dim noticably, and then about half a second to a second later it rises back up. Have not really found anything in the house that's the cause so it must be the power company. Unfortunately (i assume) this is also making my B+ sag as my volume goes down and then back to normal again closely following the lights. only solution for that would be a massive capacitor bank? or is there a different, simpler solution
I do not see any country info in your profile, but if you were in the US you could contact your utility and complain of consistent sags - they are normally good about checking the quality, and in fact the Public Service Commission often requires them to respond to a customer complaint.
Beyond that, if it truly occurs once per hour it is likely a problematic regulator or a parallel load starting up. Are you rural or urban? Tree branches tend to do this, but not on a regular basis.
Beyond that, if it truly occurs once per hour it is likely a problematic regulator or a parallel load starting up. Are you rural or urban? Tree branches tend to do this, but not on a regular basis.
You could try an uninterruptable Power supply like those used on PC servers.
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You would need to find one that matched the wattage input of your amp too.
This will solve the problem completely but my feeling is that you would be far better off seeking the root cause of the power dips rather than "black-boxing" the problem.
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You would need to find one that matched the wattage input of your amp too.
This will solve the problem completely but my feeling is that you would be far better off seeking the root cause of the power dips rather than "black-boxing" the problem.
I live in the boston suburbs. Ill investigate home appliances a little more and if I find nothing I'll give them a call
I currently am using a tube rectifier to avoid as much switching noise as possible. But you do have a very good point
I would simply regulate B+. With my tube regulated supplies I can flick the power switch on my amp, and the amp continues working for several seconds like nothing happened, then it slowly starts to die out. If the power dip is longer than the regulator can deal with continuing normal operation, at least the change in volume would be very slow compared to unregulated.
Of course there are also sonic benefits from regulating B+. You essentially separate the PSU from the signal parts, eliminating any sonic penalties from caps etc.
Of course there are also sonic benefits from regulating B+. You essentially separate the PSU from the signal parts, eliminating any sonic penalties from caps etc.
Get on to your power company and complain.
How rural are you? if you are at the end of a long line with someone else they may be pulling enough current to drop the voltage.
I dont know too much about the US distribution system but I guess you have a transformer for your house or a couple of houses. If this is the case then it is almost certainly either a bad connection on a pole (pretty likely) or one of your neighbours is into firing up a welder/compressor/large cooler or AC every hour or so.
If you put on a large load does the voltage drop?
Cheers Matt.
How rural are you? if you are at the end of a long line with someone else they may be pulling enough current to drop the voltage.
I dont know too much about the US distribution system but I guess you have a transformer for your house or a couple of houses. If this is the case then it is almost certainly either a bad connection on a pole (pretty likely) or one of your neighbours is into firing up a welder/compressor/large cooler or AC every hour or so.
If you put on a large load does the voltage drop?
Cheers Matt.
yea large loads drops the voltage, plugging in my pc for instance dims the lights momentarily. so does turning on my amp. and a vacuum cleaner will keep the voltage low until you turn it back off. on the other hand, my amp uses a 400 VA transformer, my pc power supply is 1kw rated, and a vacuum cleaner all have large inductance so voltage drop is expected?
i believe i am pretty much at the end of the line wire wise, im right on the down boarder (no houses for about 1000 feet past my house) and as far as i can tell the transformer has 3 or so houses before me and perhaps a whole circle worth of houses in addition... when i moved here many years ago there was only a max of 7 people on the circuit even in the worst case of the circle being on that transformer, now there is 11 or so with circle included 7 without
i could sit here with the meter plugged into my outlet if it matters how low it goes. i notice it the most during ~4-9pm and i dont think i've ever noticed it during the am/noon time without an explanation in the house
i believe i am pretty much at the end of the line wire wise, im right on the down boarder (no houses for about 1000 feet past my house) and as far as i can tell the transformer has 3 or so houses before me and perhaps a whole circle worth of houses in addition... when i moved here many years ago there was only a max of 7 people on the circuit even in the worst case of the circle being on that transformer, now there is 11 or so with circle included 7 without
i could sit here with the meter plugged into my outlet if it matters how low it goes. i notice it the most during ~4-9pm and i dont think i've ever noticed it during the am/noon time without an explanation in the house
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only for the duration of the voltage drop, i run in class A so any change in voltage will probably be noticable. my final capacitor stage only has a time constant of around 0.21 seconds, so a second or two of lowered line is enough to drop the voltage on my B+
If you go back to my first comment i did make note that i could increase my filter capacitance greatly to compensate. but im presently at 188 uF,
needing 300~330 mA at presently 380 volts is a lot of power. I would need about 800 uF to get 1 second, which would be sufficient to 'eat' the voltage drop, i suppose, but i think that is hitting absurdity. especially for the sake of inrush
i would run a regulated supply but unfortunately regulator tubes can only handle about 40mA
If you go back to my first comment i did make note that i could increase my filter capacitance greatly to compensate. but im presently at 188 uF,
needing 300~330 mA at presently 380 volts is a lot of power. I would need about 800 uF to get 1 second, which would be sufficient to 'eat' the voltage drop, i suppose, but i think that is hitting absurdity. especially for the sake of inrush
i would run a regulated supply but unfortunately regulator tubes can only handle about 40mA
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The 240V distribution you are on is undersized, so regardless of who or what is responsible, the tiny little transformer they are feeding you with isn't going to cut the mustard. The utility will certainly correct the issue if you contact them. Same thing happened to me. They thanked me for the call, since they were not aware this remote location was being overloaded. Within three days I had a nice big transformer mounted on a pole, serving 4 houses instead of 11.
A regulator would handle overvoltage well, but I doubt if it would handle undervoltage as effectively. Unless the pre-regulator voltages are so high that what ever voltage sag, still remains in the regulation range.
You can build a simple AC line regulator. It requires a small transformer with the primary across the AC line and the secondary in series with it.
One method is to use a tapped secondary and triacs to select which tap is used. The other method is to use a diode bridge in series with one of the input conductors and place a power MOSFET inside from + to - a photo voltaic converter drives the power semiconductor based on the out put voltage.
One method is to use a tapped secondary and triacs to select which tap is used. The other method is to use a diode bridge in series with one of the input conductors and place a power MOSFET inside from + to - a photo voltaic converter drives the power semiconductor based on the out put voltage.
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