Do AC line filters make a difference?

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Nope. Not worth it. Any decent power supply (including those in components like home theater amplifiers) filters all of the power that goes in, so there's no need for an external filter. Besides, AC power from wall outlets is pretty darn clean anyways.
 


Head in sand much? Put oscope on your wall socket, then tell me that it is 'clean'. Or that the OP's power is 'clean' using your crystal ball... You are correct, in that most well built PSU's with PFC will filter out many of the ripples, spikes etc. that your power company produces, but there is no real substite for a good UPS. My UPS starts beeping on 'low power' most every business morning starting around 07:30...
 
Nope, my head isn't in the sand. I just know exactly how much modern power supplies can take before it's a problem. I also know what the power company has to deliver to your house. What kind of "low power" warning is it BTW? Low voltage?
 


Careful, it might be nice where you live, but in Colorado, our power is pretty scary.

Im sure there are also places in the third world this applies as well.
 


My UPS will handle from 250VAC down to about 200 VAC without whinging. Many mornings my power drops to 195VAC, I've seen it as low as 185VAC. I've never gotten an alarm related to overvoltage, unless it was related to a brief surge after a full loss of power.
 

I'm in Colorado, just so you know :)

And yes, I've seen oscilloscope readings of the power coming out of the sockets at my house (of course, it helps that my dad worked for the power company for many years).

As for the voltage - I have never seen the voltage in my house below 114VAC, and never above 122VAC. It's actually fairly impressive how stable it is.
 

Logitech X-230s, and by the rear 3.5mm jack. Then again, it could be the onboard audio; this motherboard is pretty old.
 
That's probably the first thing I would try. The other thing is that the integrated amplifier in many computer speaker sets has a lot of noise at high gain levels. If your onboard audio isn't the problem, make sure that your software volume level is at maximum.
 
The main thing that a line filter, when coupled ahead of a surge suppressor, will do is to slow down and broaden noise impulses to give more time for the transient suppression circuits (generally MOV's, gas tubes, and/or zener diodes) to work.

That receptacle on the PSU that the power plug connects to is a line filter. And switching transients generated by the PSU will be far larger than anything coupled in from outside.

And the line filters provide no protection for out of tolerance supply voltages. For that, you need a UPS or some sort of active voltage regulator.
 
Any one got any opinions on Toronto Hydro's power reliability? And how do I measure it? I'm just concerned that my HDD's platter may start spinning +/- 1rpm, and there will be data write errors... When my mom has the washing machine on, incandescent light bulbs dim for each revolution of the washing machine lol. Is that undervoltage or not enough amps feeding the power grid?
 


thats not an undervoltage issue or not enough amps. That is the fact that the washing machine uses an AC induction motor, and causes a power ripple every time it turns hard. This is why they make motor start capacitors, which reduce that ripple. I guarantee that the washing machine has one in it. As for your hard drive, you probably won't have a problem since:

1: your power supply will filter out almost all ripples in the electricity, and
2: the motor in the HDD is a stepper motor, which means a controller tells it to turn so much in steps. (hence the name stepper motor). So even if the voltage drops quite a bit, it will still turn the same speed, but will draw more current to get the energy it needs.

The best way to measure the "reliability" is to get a hold of an oscillascope and look at the graph. It may come out weird since the AC in the wall is not the true sine wave, its a mix between a square and sine.
 
ok i set you a little crooked with that last post.

the wall outlet is in theory outputting a true sine wave, the normal wave for electricity. However, due to the many different loads that are put on that electricity, the sine wave becomes distorted, and when read by an oscillascope, will be distorted.
 
Ahh ok. Man sounds like you know something about everything lol. So er... anyone know how reliable a 30 year old house's power grid is, using Toronto Hydro?
 
Last Resort - Start Capacitors on AC Motors are just that the Start the motor rotating. They do this by providing a 90 degree phase shift between the two windings. Has noting to do with reducing line noise.

If truely concerned about "brown" out s (The decrease in line voltage - ie lights momentarily dim when fridge compressor comes on or vacuum cleaner is turned on) or ac noise the get a line-voltage-regulator.

Two types (1) the APC with constant REGULATED output and the magnetic Amplifier.

The mag amp is not as common. Basicly it uses a step up transformer on the input and a step down transformer on the output. The amoumt that the voltage is stepped up is controlled by controlling the mag field which is controlled by the output voltage. Much better, but BIG and Heavy and of coarse more expensive. Another disavantage - it does not provide back-up power
 


:heink:

Sorry it's midnight, my brain is fried. Good thing I've got tomorrow off lol.

I get the brown out thing, didn't get that last paragraph about... w/e it is lol. Simple english please 😀 So how bad are brown outs? I get a lot of them, as you described, when my mom turns on the washing machine (I keep telling her not too turn it on when my computer is on, her stupid feminine brain keeps forgetting! I heard that girls have to tie emotions to memorize stuff, maybe I'll emotionally hurt her and she'll remember :lol: ) or when the refrigerator starts up. Do brown outs cause any damage? I've got a Corsair 400CX PSU right now with 99% active pfc or something (at least I know it means 'power factor correction 😀 ), would that smoothen out the brown out? I've been looking at UPSs and power conditioners, but they're pretty expensive... and they're rated in VA or something... say I draw 750watts, how much VA would I need?

Sorry to steal your thread ponchato, thanks for all your professional help, RetiredChief and the last resort :)
 


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Honestly, you are fine. Unless the voltage is dropped below 90V, you're still running within the specified input voltage on your PSU, and nothing should happen to harm anything.
 
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