Think my fridge might be causing small power spikes?

[westom]

Re: Think my fridge might be causing small power spikes?

My fridge was causing power spikes. Tried MOV's across power which helped with the voltage spike but the EMI was still a problem for stereos and telephone.
I added 0.033uF 1kV cap across the fridge's thermostat and that cured it.

Which confirms what was posted previously.

You guys keep thinking this is an issue with surges, but it isn't.
The sparks - when the compressor relay closes and opens its' contacts - make RF interference which travels through the AC wires in your house.

Refrigerator is creating noise. Some also eliminate that noise by modifying the refrigerator (ie an RC snubber on its power switch).

[ben7]

Re: Think my fridge might be causing small power spikes?

My fridge was causing power spikes. Tried MOV's across power which helped with the voltage spike but the EMI was still a problem for stereos and telephone.
I added 0.033uF 1kV cap across the fridge's thermostat and that cured it.

Good job!

[redwire]

Re: Think my fridge might be causing small power spikes?

My fridge was causing power spikes. Tried MOV's across power which helped with the voltage spike but the EMI was still a problem for stereos and telephone.
I added 0.033uF 1kV cap across the fridge's thermostat and that cured it.

[Pentium4]

Re: Think my fridge might be causing small power spikes?

The tick is coming from the power supply...But the fan continues to run after it turns off (it's always done that) I could start testing it but I don't have any replacement parts for any of it to test with good components. I'll upload a short little video

[westom]

Re: Think my fridge might be causing small power spikes?

The mobo flashes red and makes a loud tick before it shuts off, do you think it is a coincidence or not with the fridge?

An honest answer must first identify the defect. Nobody can say what is defective without specific numbers. To have the defect identified and problem solved in the next post means buying or borrowing a multimeter. Typically $5 or $18 in any layman's store including Harbor Freight, Wal-Mart, and K-Mart. More expensive ones in Radio Shack, Home Depot, Lowes and Sears.

One minute of labor; taking numbers from six wires (and not disconnecting anything) means a definitive answer. To both identify a defect and to answer your refrigerator question.

The other alternative is to just start replacing good parts until something works. Also called shotgunning.

Almost no defects provide a visual indication. Observing without a cheap and simple tool (multimeter) is typically fruitless. But your choice. Get numbers to have all questions answers. Shotgun. Or hope to 'see' a failure.

Some background. A power controller decides when the PSU powers on and off. A controller powered on the computer. Three seconds later, powered the PSU off. Why? What is it seeing? Or is that controller defective? Your symptoms are classic of decisions made by that controller. Numbers would say more.

[ben7]

Re: Think my fridge might be causing small power spikes?

The mobo flashes red and makes a loud tick before it shuts off, do you think it is a coincidence or not with the fridge?

Hm, It is hard to say, but I think the fridge did not cause it.

Where is the tick coming from? and arc? or an on-board speaker (like, the liiiiiittle black ones)?

[Pentium4]

Re: Think my fridge might be causing small power spikes?

The mobo flashes red and makes a loud tick before it shuts off, do you think it is a coincidence or not with the fridge?

[ben7]

Re: Think my fridge might be causing small power spikes?

Son of a bitch....My computer will only turn on for about 3 seconds and shut down

PSU?

Shorted mobo?

Open it up, and see what it looks like inside!

[Pentium4]

Re: Think my fridge might be causing small power spikes?

Son of a bitch....My computer will only turn on for about 3 seconds and shut down

[Pentium4]

Re: Think my fridge might be causing small power spikes?

I think it is broadcasting RF because music on the pathetic little Dell speakers sounds more distorted when the fridge is running.

This morning....I woke up and found my computer off, which I don't think is good....I leave it on 24/7, I unplugged it and now I'm scared to plug it back in when I get home!!!

[budm]

Re: Think my fridge might be causing small power spikes?

Yep, that spark will inject the spike into the power line and it also generate an RF Radiate noise that travel through the AIR that can be easily be picked up by high impedance input circuits such as audio pre-amp input section of the amplifier.
Like I said, you need to check and see if there is any snubber network on the relay/switch for the controlling the compressor. Also best to reduce the noise at the noise source.
I doubt that cheaply made fridge will have any EMI filter in it. We had just spent $6000 for EMI test for one little product that has switching power supply and 16MHz Xtal for the processor.
Radiate noise will be harder to control due to wide bandwidth of the noise.

[ben7]

Re: Think my fridge might be causing small power spikes?

You guys keep thinking this is an issue with surges, but it isn't.

The sparks - when the compressor relay closes and opens its' contacts - make RF interference which travels through the AC wires in your house. The wires act like an antenna. The wires of your computer speakers are acting as an antenna, picking up these bursts of EMR. The small voltage induced in the wires is amplified by the amplifier in the speakers, and you hear a small 'pop' sound.

A surge protector usually doesn't even have an EMI filter. I suggest that you add an EMI filter where the cord goes into the back of the fridge.

[westom]

Re: Think my fridge might be causing small power spikes?

Need to learn more? Not all semiconductor has built-in ESD/ or spike protection ...

Points 1 through 4 only dispell irrelevant myths. Point five is the OP's topics. Why are you introducing other irrelevant semiconductors? Why are you ignoring what is significant including a possible code violation? Please address the OP's noise problem. A spike that is probably no more than tens of volts. And that maybe bypassing supply circuits that make noise (and larger spikes) irrelevant.

Your reply should be discussing point 5 that said, "Fifth, topic is about noise from a mini-fridge."

[999999999]

Re: Think my fridge might be causing small power spikes?

First, all those components provided protection.

What? No, they don't. That's why the stereo makes the popping noise, because a surge makes it to the power amp stage. You're essentially suggesting that every component in everything provides surge protection which would eliminate the notion of surge protected equipment vs equipment that does not have surge protection built into the design.

Second, today 120 volts is significantly filtered; seriously reducing or eliminating spikes. Then converted to a higher voltage (over 300 volt) radio frequency spikes. Even noisy AC is converted to a higher and 'dirtier' voltage.

Which does nothing to change that fact that if you have a transistor conducting at say 50KHz, then when the surge comes in it is conducting that surge until the control or shutdown kicks in. Now where does that surge go? Even if it doesn't make it to the powered equipment (which it will to some extent) it is still handled, meaning dissipated by the PSU, not shunted to ground. If you have no shunt to ground you do not have surge protection.

Third, that outlest > fuse > transformer ... example was obsolete technology so many decades ago. Protection, that existed even back then, was not as robust.

False. Only with all digital circuits is a lower frequency PSU obsolete. Once analog is involved, as it is with most stereos at some portion of the circuit, high frequency PSU ripple is avoided in a good design. Granted everyone has their own idea whether it's better for it to sound best, have best efficiency, best size or weight, etc but generally speaking sound quality comes first in one's primary source for high quality sound.

Fourth, naive is to assume protection is only provided by a protector device. But that myth is popular. Instead, even datasheets for an interface semiconductor make obvious that myth. Semiconductor will withstand 15,000 volts once part of a circuit:

Based on what you are implying, surge damage can't exist, and yet we not only see evidence of surges getting though to equipment though malfunction but also damage. Ironically the very topic we are in is evidence of that though a malfunction that produced a pop, or perhaps we should say it functioned exactly as expected rather than malfunction because it wasn't designed to deal with surges.

Fifth, topic is about noise from a mini-fridge. Probably only tens of volts. Usually made completely irrelevant by how supplies are designed. Noise typically must bypass superior protection already inside that supply. And definitely is not hardware destructive.

It is extremely unlikely that tens of volts on a 110VAC, let alone 220VAC powered stereo would cause a pop. It is well known that compressor motors kick back surges on shutdown that are 10X that value. 110VAC line may experience surges of tens of volts several times a day but only with higher magnitude surges would a pop occur.

Listed were possible reasons for noise (including wiring in violation of code - a possible human safety problem). How to solve noise at its source. First identify a reason for noise. Then eliminate at its source what is only noise.

The most likely possible reason is quite simple. The typical appliance with a compressor produces a spike when it shuts off. Some equipment cannot deal with this spike without unintended output because it it not designed with surge suppression. Surge suppression is an intention addition of components or change in circuit design to deal with a surge. In the typical consumer electronics devices there is none.

Why would one need to solve a surge at its source if the device had surge protection built in? Because it doesn't.

[budm]

Re: Think my fridge might be causing small power spikes?

Need to learn more? Not all semiconductor has built-in ESD/ or spike protection that can handle 10KV or more.

even in 12v system can have high spike;


http://www.glseq.com/surge.htm

http://www.idxinc.com/carwash/AppNote101.htm

http://books.google.com/books?id=E9n...120vac&f=false

[westom]

Re: Think my fridge might be causing small power spikes?

In the typical stereo you have wall outlet -> fuse -> transformer -> bridge rectifier -> bulk DC power rail capacitor bank -> parallel power amp circuit and regulated preamp/buffer audio signal input circuit.

First, all those components provided protection.

Second, today 120 volts is significantly filtered; seriously reducing or eliminating spikes. Then converted to a higher voltage (over 300 volt) radio frequency spikes. Even noisy AC is converted to a higher and 'dirtier' voltage. Then superior filters, galvanic isolation, etc convert that intentionally made 'dirtiest' power into rock solid and cleanest low voltage DC. Why? Best protection and superior filters, already inside electronics, must clean 'intentionally made much dirtier' power.

Third, that outlest > fuse > transformer ... example was obsolete technology so many decades ago. Protection, that existed even back then, was not as robust.

Fourth, naive is to assume protection is only provided by a protector device. But that myth is popular. Instead, even datasheets for an interface semiconductor make obvious that myth. Semiconductor will withstand 15,000 volts once part of a circuit:


Fifth, topic is about noise from a mini-fridge. Probably only tens of volts. Usually made completely irrelevant by how supplies are designed. Noise typically must bypass superior protection already inside that supply. And definitely is not hardware destructive.

Listed were possible reasons for noise (including wiring in violation of code - a possible human safety problem). How to solve noise at its source. First identify a reason for noise. Then eliminate at its source what is only noise.

[999999999]

Re: Think my fridge might be causing small power spikes?

^ They (often but not always) survive surges merely because the period was short enough and the components needed in non-surge conditions for proper operation, had a bit of voltage headroom.

Most have few if any components commonly associated with surge protection circuits nor do they attempt to shunt the surge to earth ground. PC power supplies for example may have PFC circuitry for its inherent benefit in operation as well as inrush current limiting, output over-voltage protection, but no MOVs, avalanche diodes, gas discharge tubes, etc., and PC PSU are far more complex than the average clock, smoke detector, or vacuum cleaner power supply circuit.

In the typical stereo you have wall outlet -> fuse -> transformer -> bridge rectifier -> bulk DC power rail capacitor bank -> parallel power amp circuit and regulated preamp/buffer audio signal input circuit. Again none of the components commonly associated with surge protection are present. Where is the surge protection there except to pick diodes with as high a voltage rating as the budget and space allows? That only spares the diodes, the fuse cannot react in time to protect against typical short period surges.

[westom]

Re: Think my fridge might be causing small power spikes?

PC power supplies usually have no surge protection inside.

Every appliance has surge protection. How often do you replace dimmer switches because an air conditioner switched off? Never? Long before PCs existed, 120 volt electronics were designed to withstand up to 600 volt spikes without damage. Today's electronics are even more robust.

This 120 volt UPS outputs 200 volt square waves with a spike of up to 270 volts when in battery backup mode. Why is that ideal power for computers. All electronics already contain protection that even makes 'dirty' UPS power irrelevant.

Protection already inside a stereo means that spike is only noise. How often are digital clocks, smoke detectors, and nite lites being destroyed when a minifridge or vacuum cleaner power cycles? Never. Protection routinely inside each means that spike is only noise. All computer supplies contained internal protection long before the PC existed. Noise causes no damage.

How often does a spike from any appliance destroy the GFCI? Even GFCIs contain robust internal protection.

[999999999]

Re: Think my fridge might be causing small power spikes?

I have a window AC unit on the same circuit as a bookshelf stereo and a PC. Every time the window AC shuts off the bookshelf stereo pops. Both have been running like this for over 6 years, I do nothing about it because I'm usually not in the room to hear it and they're not valuable equipment. If I ever get really really bored I might try to clamp the spike at 200V or something.

PC power supplies usually have no surge protection inside.

[westom]

Re: Think my fridge might be causing small power spikes?

I see too many houses that don't have enough proper three-prong outlets.

Two wire receptacles are not so much a problem. More problematic are three prong receptacles where some safety ground wires are missing or compromised.

As budm's video notes, to create 1000 volt spikes means a capacitor that is also at 1000 volts. A 1000 volt capacitor installed to make a spike? 1000 volts inside that refrigerator would probably destroy any internal capacitor and even wire insulation. Assuming a capacitor even exists. Even sparking across a switch would cause its switch to destroy itself. If the refrigerator is creating spikes that high, then, as Budm notes, the solution must be installed inside the refrigerator. To also protect that refrigerator from itself.

A spike is only noise that causes no damage. If a spike is on AC mains, then any decent power supply would make it irrelevant. Any decent supply must have filtering many tens of times superior to a filter insode a power strip. (Criticism of Monster are too tame.) If a spike is entering via some other wire (ie inferior supply powering speakers, via safety ground, etc), then a solution starts by first identifying that input path. PeteS' radio is also a useful tool.

Refrigerator is creating noise. Some also eliminate that noise by modifying the refrigerator (ie an RC snubber on its power switch).