first you can never consume enough drinks for it to kill you, this has already been tried, you just get really sick before you ever get close..

second how was that a hack on the weather.gov it looked like a simple link????

fuses also act like a surge protector, in that if you stick a 250 volt fuse in your equipment it can possibly be hit by a voltage spike that might damage the equipment so a 125 volt fuse is a safer bet, especially if it's an expensive system, the manufactures put those 125 volt fuses in there for a reason, but it you have the equipment in a surge protector then you might be able to get away with it. just a little FYI from an electronics engineer.

@reddragon72

"Water intoxication (also known as hyperhydration or water poisoning) is a potentially fatal disturbance in brain function that results when the normal balance of electrolytes in the body is pushed outside of safe limits by a very rapid intake of water."

http://en.wikipedia.org/wiki/Water_intoxication

check out this link to a 4amp 125v slow blow fuse part number N4 top of the page.

http://www.electronicplus.com/content/ProductPage.asp?pagenum=6&lname=&maincat=fus&subcat=fsl

A major type of Time Delay fuse is the dual-element fuse. This fuse consists of a short circuit strip, soldered joint and spring connection. During overload conditions, the soldered joint gets hot enough to melt and the spring shears the junction loose. Under short circuit conditions, the short circuit element operates to open the circuit. Slow-blow fuse allows temporary and harmless inrush currents to pass without opening, but is so designed to open on sustained overloads and short circuits. Slow-blow fuses are ideal for circuits with a transient surge or power-on inrush. These circuits include: motors, transformers, incandescent lamps and capacitate loads. This inrush may be many times the circuit's full load amperes. Slow-blow fuses allow close rating of the fuse without nuisance opening. Typically, Slow Blow fuses are rated between 125% to 150% of the circuit's full load amperes. A little FYI from a Electronics Mechanic ;)

The maximum voltage at which a fuse is designed to operate. Exceeding the voltage rating of a fuse impairs its ability to clear an overload or short circuit safely. Fuse can be used at any voltage below the fuse voltage rating; a 250V fuse can be used in 125V circuits. Voltage ratings are assumed to be for AC unless specifically labeled as DC.

DO NOT BE AFRAID OF GO-PHONES.
I bought a Nokia 6030 Go-Phone from AT&T/cingular for 30 bucks with no contract. I was and still am a AT&T/cingular customer, and just put my sim card in the go-phone without having to extend my contract for another 2 years. T-Mobile sells the same pre-paid phone that you can put your T-mobile sim card in.

Roger,

Keep up the great work (seriously) and forget the haters who type scathing (i.e., not constructively critical) emails. Their smallness is to be pitied.

Anyway, I really enjoy your work on dl.tv, This Week in Tech (twit.tv) and, last but not least, the always entertaining and insightful East Meets West Podcast(http://www.subbrilliant.com/emw/).

Bill

Aw, who was picking on Roger? I think he's adorkable.

Sorry Patrick,
I gotta disagree with you on the fuse, voltage vs. amps discussion. If you asked ten techs about this you'd get twelve answers. But after 20 years of working on Air Traffic Control radar systems in the Air Force; I've spent more time than I like to think about trying to explain this to new techs. When talking fuses it's really all about the watts. A 15 volt 10 amp fuse is a 150 watt fuse. Once the wattage the fuse is carrying gets too great the filament heats up and melts. Technically if you could set up the conditions you could get the 10 amp 15 volt fuse to carry 100 volts at 1 amp or 1 volt at 100 amps and it would not blow. In the radar and high power radio transmitter world those types of conditions can exist and the voltage rating on a fuse is important.
But in the regular world most electronics will not create these unusual conditions, which is why you can get away with a larger voltage fuse. Your car radio cannot pull 100 amps at 1 volt without something else in the system breaking down, letting out its magic blue smoke and thus rendering it useless. Nor could your car's electrical system feed 1500 volts at point one amps to the radio. This is why you can get away with over fusing the 5 amp 125 volt fuse with a 5 amp 250 volt fuse. Just remember the new 250 volt fuse is over rated and will not protect the electronics from a low amp high voltage surge as well as the original.

Keep up the fun.
Ed

P.S If you want to see some high voltage and high current examples check out the Green Monster at http://dawntreader.net/hvgroup/david/gm.html
or this video
http://205.243.100.155/frames/mpg/500kV_Switch.mpg

sorry reddragon72 but fuses work on current (amperes or amps) not voltage.

Of course you can drink enough to kill you.

http://en.wikipedia.org/wiki/Leah_Betts

stuped question:
with P=U*I and the fuse being trigered if the power is getting too high shouldn't you reduce the amp. value if you use a fuse with a higher voltage value than the original fuse? (at a lower voltage a given fuse should be able to handle more amps than specified at it's "normal" voltage)

Love the show but I have to be honest: Roger is not good. The thing I like most about the show is Pat's professionalism and Robert's humor and honesty (and smiles). Pat and Robert could talk about anything and make it interesting because they are so good and so professional. I haven't missed a show until Roger showed up on a few episodes in a row.

I really don't mean to be mean but Roger needs to work on his on camera persona. He is such a train wreck. I have two suggestions 1) Stop the lame jokes... when he wants to say something "funny" tell him to not go there. There is no reason to tell bad puns. They are distracting and annoying... not to mention really bad... and not funny.
2) Someone should rub his shoulders to loosen him up. Yes, I understand Rog is a little nerdy and not used to being on camera but it could be a really good lesson in confidence for him. Just loosen up. Jump up and down... pretend you're Rocky before you get on and maybe with those two suggestions you'll get better.

If Pat and Robert like Roger there must be something good about him... but just loosen up a little and stop telling those really horrible puns while on camera. Pretend you're Jon Bon Jovi and jump up and down and do some push ups before a show to loosen up.

I've seen every show and love what you do. I watch podcasts more than I do regular TV. Revision3, DL.TV, Cranky Geeks, Smodcast, Buzz Out Loud... I love web shows and thank you so much... please advertise to me so you get paid. I love all your shows.

An additional comment about the fuse your viewer had the question about... That T4AL is the descriptor for that fuse type: T (Time delay or slow blow) 4 (Amp) AL (Axial Lead). If he still hasn't found a replacement, he can probably find one at Newark Electronics, Mouser, Digikey, or any other electronics supply source. He'll just need to know the size/dimensions of the fuse he's replacing.

I had an acquaintance who drank at least 4 pots of coffee per day. One day he quit cold turkey and later that day went into cardiac arrest. The doctors said his body had become dependent on caffeine. The cardiac was due to withdrawal.

On the fuse bit, the voltage is also important, otherwise why would a manufacture put a 125 amp fuse in there when a 250 would work, if that was the case then lets make every fuse for every situation rated at 1000v and be done with different voltage fuses. The volts are needed, and you should ALWAYS get the replacement fuse that matches the manufacture rated fuse. Trust me on this, the voltage is important.

now for the drink issue. All those that wrote in about the water issue, it is very well known, as you remember the "hold your wee for a Wii" contest where that lady died. Well if we where discussing water then that would be true, but here we are talking about caffeinated drinks that have tons of other additives that will make you sick if you drink enough of them so you could potentially never make it to the point that the caffeine consumed from the drinks would kill you. in other words the drinks themselves would make you sick before the caffeine could kill you...

A fuse is not a power device. It is not rated in WATTs as Ed Tourigny posted above.

Fuses are rated in AMPS of current. If you exceed the current rating specified - the fuse will open which will stop the flow of electricity and protect the rest of the equipment.

A 1A 125V fuse will not tolerate more than 1 amp of current. You certainly can NOT push 100 AMPS of current at any voltage through a 1A fuse !!!!

A slo-blo will tolerate brief surges of current past its rating ... but sustained current will cause the device to fail to protect the device.

With regards to the voltage rating on the fuse ... its there to provide an indication of the maximum allowable (read test voltage) for the fuse.

Everything costs money so manufactures can sell you a fuse with a 125V rating cheaper than a fuse that is designed to handle the same current (say 1 Amp) for a 250V volt system. But both fuses will work on a 125V circuit and allow just 1A of current.

And if you are working with low voltage devices - say a car stereo at nominal 12 volts - then either a 50V, 125V, or 250V rated fuse will work just fine.

And you should NEVER substitute a fuse with a higher amperage rating into a device.

People ... this is not rocket science. Maybe it is to some folks. But if you don't understand it - you should not be teaching others about it.

Please ignore all the incorrect and misleading comments regarding fuses above. If you really want to know, read a good text book. There is much more to it than at first appears. It is NOT AT ALL to do with Watts, it is NOT ONLY to do with volts and it is NOT ONLY to do with amps.

Unless you know what you are doing:

NEVER replace a fuse with one of a higher current rating - it might kill the equipment, cause a fire etc.

NEVER replace a fuse with one of a lower voltage rating - it might kill you because the fuse may blow but could set up an arc that will allow current to still flow.

NEVER replace a quick blow fuse with a slow blow fuse. You can do it the other way but expect the fuse to blow.

And for recursion, NEVER take advice from an internet forum without doing your own research.

Anyone count how many times Patrick said "generally speaking?" lol wow!

@reddragon72, s, Tucker & Tourigny

Fuses are more complex than it appears... Voltage specification on the fuse does not relate to the power needed to break the fuse. Voltage specification on the fuse is the voltage under which broken fuse will not be shorted by the arc across the void made by its melting. Hence, 250V rated fuse, when broken/melted will not arc-short due to the voltages of 250V or less. Apply, say 360V on such dead fuse and sparc may fly, current go through and your equipment might get fried.
Hence, voltage specification of the fuse multiplied by its amperage specification does not yield the power needed to melt the fuse. Voltage specification and the amperage specification relate to two completely different issues and their multiple is meaningless.

Fortunately for us, this common misconception is the safe one. If you do imagine that the product of specified amperage and voltage is the power needed to melt the fuse and than use that assumption to pick amperage for the lower voltage than specified, you will 'err but in the safe directioon.

My qualifications to claim this: advanced degrees in Electrical Engineering, Physics and some close personal calls with the tank full of batteries, wrong wiring and the palm sized fuses glowing red, yellow, white, aaaaaa... (tank as in the armed thing with the gun on it...).

I have two different comments about show 181. First I have to say that Roger Chang usually does better on camera than Pat. Pat has had years of experience but can't seem to get through a sentence without saying 'Basically'. And he often't can't get through a sentencfe without restarting it. I like Pat but he is NOT an on camera pro. :-(

Second, the issue of fuzes. A fuses voltage rating is simply what voltage ir can operae in without arcing badly when it blows. So any volrage equal to or above that of the system, i.e. 12V for a car, 120 volts in a home, etc. is fine.

And using the term 'amperage' will show that you are not a pro when it comes to electrical stuff. 'Current' is the correct term. Don't ask my why since voltage seems OK.

Jim

Ya'know I mostly delete my dl.tv files after Ive watched them but the past few I havnt as they have been really great shows. Roger is a great host, Patrick n Robert are stella hosts but its nice to have someone different every so often and Roger does the job perfect.

Its also wierd many of the stories seem to pop up a few days after I needed them. The fuse im my Logitech Z5550 blew the other day and I had trouble finding the fuse eventually finding it on eBay and now its on dl.tv a quick google on the fuse model strangley found me to many stories all detailing logitech speakers seems logitech dont quite have a perfect design for the power supplies in thier speaker range.

Roger,

I do not think you need this but Claudia Johns is the one that needs to relax. It is a tech show and btw as you know you were on Call for help.

You do seem like you are nervous but other than that you do an excellent job and fill in when Pat and Robert are off.

If this person who's name I will never speak of again is that distrubed. I wonder how many "volts" of "Caffeine" would they need to let it go.

Ah and no I do not want to get in to the amp voltage thing. Scarey

When a fuse blows it opens a gap to stop the flow of current. Voltage can always arc across a gap of a certain size. A 125V fuse opens a gap that 125 volts CANNOT ARC ACROSS. But 250 volts might be able to arc across this gap thus nullifying the effect of the fuse. In general, as the voltage rating goes up the size of the fuse goes up. Why? So it can create a bigger gap. So NEVER use a lower voltage rated fuse than that specified for the circuit.

I've got no problems with Roger -- he just has a different style than Pat and Robert.

Claudia Johns - What complete rubbish you speak. Your opinion is just that, an opinion and a bad one to boot. My opinion is that Roger is just fine. This isn't some glossy fake show with people with capped teeth and fake smiles blowing sunshine up your skirt telling you about Lindsay Lohan et al., it's a tech show by real people for real people. If you are looking for that other kind of tripe then find when Entertainment Tonight is showing in your area and happily watch that. And your worthy opinions would be better appreciated over at TMZ where you can impart your sage advice to such topics as Paris Hilton's driving or Miss New Jersey's fax beaver shots. As for the cast and crew of this fine tech show - it's wonderful the way it is. Roger Chang is great, his 'persona' is himself, as is Robert Herron and Patrick Norton. That's what I like about this show, it's real folks giving me good tech information about things happening in tech today. No bull, no beautiful talking heads with empty heads, just people who know what they are talking about. Unlike yourself.

Ok on the fuses one last time. A fuse blows due to heat build up cause of current flow. When to much current flows the fuse will blow. Heat as stated is what causes a fuse to blow, and heat(watts) is generated from a mix of current and voltage. I have personally seen a 250volt fuse blow when plugged into a 600volt circuit that did not exceed it's current rating, and once it blew it did NOT arc, that is just the silliest thing I have heard in a long time. A fuse can open up completely or break just enough to stop current flow, there is no way for them to make a fuse that will blow in multiple places causing a bigger "gap" for the voltage to jump through. Also voltage generally will NEVER jump until it reaches at least 380 volts with the air around it at STP(standard temperature and pressure) LOOK IT UP!!! so to say that a 250 volt fuse will have a less arc ability is complete crap. If that theory held true then combustion engines would need a WAY lower voltage than say the standard 7000-14000 volt producing systems that we have today to create an arcing voltage at VERY low current to jump accross a .045 inch gap. Please lets not further this.

heat blows a fuse and we all know that heat is wattage, and wattage is the product of both voltage and current.

I don't know but if 125 volt and 250 volt fuses are made they must be made for a reason, and one is NOT cheaper than the other. And manufactures put 125 volt fuses in there equipment for a reason, and it is not due to 250 volt fuses costing more, as several sites show the same price for all there fuses regardless of volt or amp.

man this is a good debate, and I am loving it.

I just started watching this on TiVo. I think Roger's doing a fine job. However, I'm watching for Patrick... he's hot!

I think you're hilarious, Roger. Don't change a thing!

Just wanted to say Monster could probably kill you in less than 83 cans, because it has Taurine and all those other great chemicals in it.

I'm gonna try to clear some things up. A fuse is installed in series of a wire so current passes through it. Under normal current levels that the fuse is rated for the conductor inside the fuse has enough surface area to allow the that current to flow normally. When current exceeds the rating of the fuse the conductor inside the fuse melts rapidly or slowly depending on the kind of fuse used. Once the fuse has opened the voltage rating determines the safe amount of voltage the opened gap will insulate against conducting. When you have an open point in any circuit the potential difference manifests itself across the break. There could be in some instances where the gap blew slightly and could pose a arc risk, hence allowing momentary current through an assumed protected circuit. The voltage rating of a fuse has nothing to do with how much it can handle before it will open, since applying fundamental ohms law power formulas result in an equation that doesn't use voltage at all. P = (I^2) * R. The conductor within the fuse has really small resistance in most calculations it can be ignored and be set to zero ohms(Check a good fuse with an ohm meter to verify this). Voltage will drop across a resistance, but with the conductor having zero ohms of resistance V = I * R, if R is zero the voltage drop is zero even if I is really high. When a fuse blows it creates a lot of heat and byproducts of smoke and particles which change the isolating properties of the air inside the sealed fuse case. This may allow arcs to occur at even lower ionization potentials.

I also forgot to mention that since the resistance of a closed fuse is zero, electrical power has nothing to do with the fuse opening either. Power is a function of both current and voltage, and there is zero voltage across a small length conductor like that of a fuse. When you get into long power lines you have much greater resistance and hence voltage drops and power loses. However, in a fuse the more current you have the more charge quantity you have one amp = 6.25 * 10^18 electrons flowing past a static point in one second! The more current you have the more electrons are moving creating friction by colliding with positive ions and atoms inside a conductor.

I have read the various remarks about fuses. I have to admit I'am more confused than before I read any of them.I have a 64 Rock-Ola jukebox , it blew one of the fuses,a 125 volt 6 amp fuse.I want to use this correct size fuse,only I can't find any locally.Where might I find one..?? DEE LINN

I have read the various remarks about fuses. I have to admit I'am more confused than before I read any of them.I have a 64 Rock-Ola jukebox , it blew one of the fuses,a 125 volt 6 amp fuse.I want to use this correct size fuse,only I can't find any locally.Where might I find one..?? DEE LINN

one more vote for Mark H's explination of fuses. reddragon72 -> P does = V*I but the V refers to the voltage DROP across the fuse, not the circuit voltage with reference to ground. Since you don't know the voltage drop across the fuse, sub V=IR witch brings us back to P=(I^2)*R and since R is near zero in a fuse, power is near zero regardless of current. By your explination, a 400,000 V power line with heavy current passing through it would be glowing hot.

As for the voltage rating of fuses, I'll have to take your word on the spark gap theory, makes sense though.

I have to agree with Mike "And for recursion, NEVER take advice from an internet forum without doing your own research."

So I did and found this very useful pdf titled "Introduction to Circuit Protection", especially the section on Voltage Rating. It helped me.

http://www.teccor.com/data/en/Product_Selection_Guides/Fuseology.pdf