Cleaner Signal

T

ThirtySixBelow

Gawd
Joined
Dec 4, 2004
Messages
846
Is there anything that I can purchase that would help me get a cleaner power signal to my computer. I was at best buy a while back and saw something that monster made that helped get a cleaner signal to the tv to improve picture quality. Do they make anything like this for the computer? Would a UPS help with this, or is it just a battery backup? Thanks
 
That monster cable power bar is useless... And unless they've got a full regulating AC->DC->AC system crammed into there (and they don't) there's no way they can claim that it "purifies" the AC signal.

Besides, any TV or computer power supply that's worth anything shouldn't care what sort of noise comes in over the AC... The incoming line filtering should get rid of any high frequency crap, and the regulation loop will take care of low frequency stuff.
 
A ups is always a good idea but I dont know if I would call it cleaning up power. UPS will stop bad fluctuations like power spikes and brown outs but they have to be pretty bad to flip to battery. Mine does 126 to 114. That is the high sensitivity. If you are talking about the dirty like when you run a vacuum cleaner causing variations. I dont think computers are suseptable to that because it converts ac to dc. But not positive.
 
radnads said:
A ups is always a good idea
Click to expand...

and a High quality supply
most supplies will have an AC Ripple on the +3.3V\+5V rail of 50mV and on the +12V rail(s) of 120mV which is spec (and would include that Fortron)

some supplies have ferrite toroids on the some of the leads (just like the monitor cable)
(like the Powerstream on the Video card and HDD lead)

some supplies exceed spec in ACRipple through superior filtering,
like all the rails at 10mV
( the PCP&C Turbo Cools)

http://www.pcguide.com/ref/power/sup/specElec-c.html

Ripple: Also sometimes called "AC Ripple" or "Periodic and Random Deviation (PARD)" or simply "Noise". The power supply of course produces DC outputs from AC input. However, the output isn't "pure" DC. There will be some AC components in each signal, some of which are conveyed through from the input signal, and some of which are picked up from the components in the power supply. Typically these values are very small, and most power supplies will keep them within the specification for the power supply form factor. Ripple values are usually given in terms of millivolts, peak-to-peak (mVp-p). "Peak-to peak" refers to measuring the AC voltage from its negative maximum to its positive maximum (see here for an illustration of what this means.) Lower numbers are better.
Click to expand...

a UPS is certainly going to make the job of the PSU easier, and deal with spikes and brownouts\blackouts
but its not going to impact the AC Ripple all that much from what I gather
ferrite beads on the other hand could

http://www.topower.com.tw/home/product_option.htm
scroll down to REMIC Control Technology

in a do it yourself senerio selecting a ferrite core is tricky,
likely need a sample pack (pdf) and an oscilliscope
or experience, personally Id ask gee what he thinks might be a good idea

OCZ sells those cables seperately though, as to real world benefit.....
would depend on a great number of other variables
 
Depends on what kind of UPS you get. A standby UPS is a unit with battery that only comes online when the power goes totally out, solely for the purposes of having battery power long enough to save everything and safely shut down. An inline UPS on the other hand, does much more, including the AC>DC>AC system that 'Gee' pointed too. An inline UPS works like your car's alternator and battery - the alternator charges the battery, and the battery powers everything in the car. When you have an in-line UPS, your comp runs off the battery's clean power at all times, and the AC power from the wall is used to power the battery. It's the best power protection that money can buy. BTW, this high quality only applies to items connected to the UPS's battery powered outlets - the 'surge only' outlets are just as bad as a regular power strip/surge protector. A close second to the inline UPS is a line conditioner, which uses sophisticated transformers, capacitors, varistors, and other circuitry to smooth out fluctuations in current from the wall, and ensure that 120V 60Hz AC is delivered to all of the devices connected to it. A line conditioner is capable of bridging a brownout where the lights go out for a second, and deals with spikes, surges, line sags, ripple, etc, but does nothing against a full blown blackout.
 
an online UPS though is a very rare bird at any reasonable price and smaller capacity
though you can make your own

The DIY (or, if you must, "Ghetto") UPS

I would advise an active PFC supply to go with that however (or even a line interactive UPS once its switched over to batteries)


Power Supply System Integration Part 2: Battery Backup @ Power Electronics Technology

UPS Nonlinear Loads

Most end users are oblivious to the problems encountered when an online UPS interacts with nonlinear load, such as a switchmode power supply. Fig. 3, on page 42, illustrates the interface between an online UPS and a switchmode power supply. The switchmode supply within the host system consumes its current in high amplitude pulses, and as a result overloads the UPS, distorts its output and degrades in performance. This isn't the case if the SMPS has power factor correction (PFC); and in the United States most SMPS don't have PFC.

Repeated measurements under practical conditions show that in non-PFC SMPS, the current peak to rms ratio reaches a crest factor in the range of 2.5 to 3.5. This high crest factor imposes a difficult load for the UPS.

Manufacturers specify UPS capacity in volt-amperes, and set the UPS current limit with resistive loading. This affects the user in two ways: first, the actual power (in watts) that the online UPS can deliver is 75% to 80% of its VA rating. Second, the UPS cannot support a nonlinear load like a SMPS to full power capacity. In fact, it can support an SMPS only rated to 30% to 40% of its capacity. A 1kVA online UPS will only be suitable for backing up a system energized by a 300W to 400W (non-PFC) switchmode power supply. Attempts to draw higher power by the SMPS will severely distort the output of the UPS and may result in shutdown. Some UPSs support nonlinear loads to various degrees, but the above rule is safe to use as a guideline.

The whole idea of generating a high-purity sinewave within the UPS, and then rectifying it within the SMPS is wasteful. A UPS may be deployed to run non-electronic loads, such as lights or motors. However, this is a minor portion of the market for online UPS. Many applications back up computers and telecom devices, as well as instrumentation systems used for critical applications. In all of these applications, the immediate load for the UPS is the SMPS within the systems. Peak current and inrush current are associated with this load at startup. This current of 40A to 80A per SMPS will cause the UPS to shutdown due to overloading, or the UPS must transfer the load to utility to draw its inrush.
Click to expand...
 
You must log in or register to reply here.
Back
Top