Author Topic: Holy overpriced bs batman  (Read 13019 times)

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Offline XOIIO

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Re: Holy overpriced bs batman
« Reply #25 on: May 10, 2014, 05:28:52 pm »
You can choose between a cheap standard glass fuse rated for mains voltage and intended to be used in your common electronics device, and an expensive DMM fuse rated for 1000V and able to break high currents while preventing splinters of glass all over the place. If you're just working with low voltages and currents the standard glass fuse is ok but you should put a sticker on the DMM stating that in case someone else uses the DMM, so he won't trust the CATIII or whatever rating printed on the DMM. And remember, cheap DMMs got cheap fuses.

Yeah, around here nobody else is even going to touch it though, so no real need to mark it. I still plan on the upgrade.

The worst part is that the 10 amp fuse is also a glass 5x20mm one. I can't see the 500ma shattering but this one, yes. I found a ceramic one from an old meter that is good though, so I'll toss that in with the new 500ma one until I can mod it.

Reckless actions should never be wrapped in a protective shroud labeled "he is just learning". Recklessness is characterized by indifference to danger and acting without forethought. Quick searches of Youtube videos show this to be true.

Unfortunately, recklessness has a spectrum which includes both blowing 500ma fuses and, at the opposite end, the loss of human life. You have already blown the fuse. You have already moved further up the spectrum by rationalizing how YOU don't need the safety fuses inside your meter. Please consider re-evaluating any attitude which enables further movement upward in this spectrum.

Consider the responses to your post to be genuine concern for your safety and continued success in your future endeavors. Don't lightly brush off suggestions or corrections with which you may not agree and attribute them solely to someone's  "hate boner" toward you.

If I read correctly, the OP, with the meter with the blown fuse in question, was NOT looking to replace the fuse with a bodge. He was merely trying to start a conversation as to why fuses are so damned expensive, for what they are. Sheesh.

@mariush: In no way was the OP being Reckless in his work. He had the meter on the current on the highest level and worked down when he wasn't getting a reading, obviously assuming that there was less current flowing then he thought. He didn't know that there was a significant break in a wire that was open-circuiting. For all we know the guy was measuring current from a simple 9V battery, which is more then able to output 500mA

Added to that. I would call a $5 fuse replacement a better lesson then a $100+ meter replacement, plus whatever medical bills would come with that.

Obviously mariush/Joule Thief you think that anyone with a lower knowledge base then you should not be allowed to start to learn anything electronic. I believe you will have a busy life ahead of you, with all that travelling around the world to judge every Tom, Dick and Harry that wants to plug a cable in anywhere.

Thank you, I don't know where he got the idea that I was saying that I don't need a fuse.

I was going to suggest home depot $3.74 for a pair 0.5A, 250V, 5x20mm, fast blown:
http://www.homedepot.com/p/Cooper-Bussmann-GMA-Series-500-mA-Silver-5mm-x-20mm-Fuses-2-Pack-BP-GMA-500MA/100149086

mouser search for the same part for datasheet:
http://www.mouser.com/Search/Refine.aspx?Keyword=BP-GMA-500MA

Edit: but not sure if Home Depot operates in Canada, I'm assuming it does.

They do, but I don't know if thy have those here, anyways home depot is a similar trip so I'll just get the ones for 66 cents. At least those ones are in a two pack.

Offline XOIIO

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Re: Holy overpriced bs batman
« Reply #26 on: May 10, 2014, 05:36:15 pm »
Uuuuuuuuuuuuuuuuugggggggghhhhhhhh

Damnit, I forgot, they are closed on weekends too, I don't know why, it's such a damn pain when you need stuff.  |O

And of course home depot sells multimeters, but doesn't carry replacement fuses.

Offline linux-works

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Re: Holy overpriced bs batman
« Reply #27 on: May 10, 2014, 05:53:10 pm »
just wrap some aluminum foil around it and replace in the slot.  should be good for the next 1000 years.

(is he serious?  that's up to you to guess.)
 

Offline Legion

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Re: Holy overpriced bs batman
« Reply #28 on: May 10, 2014, 06:55:14 pm »
Well, I'm out looking for a 500ma fuse for my multimeter as I blew mine by accident, we have two electronics stores, one halfway across town that is too far for this and a small chain called the source (formerly radio shack), I phone them up since the automotive store had none, they have a fuse, but they want $5 for it. Is it just me or is that freaking insane? I can't imagine how much HRC fuses would be if they sold them, sheesh

I used to work at the shack in high school. I always used to wonder how they stayed in business until I worked there. The markups are just insane; the POS system displayed the cost and I'd routinely see items with costs around $0.35 which retailed for $19.99. I guess with markups like that you only need a couple sales a day to stay afloat.
 

Offline miguelvp

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Re: Holy overpriced bs batman
« Reply #29 on: May 10, 2014, 07:10:05 pm »
Uuuuuuuuuuuuuuuuugggggggghhhhhhhh

Damnit, I forgot, they are closed on weekends too, I don't know why, it's such a damn pain when you need stuff.  |O

And of course home depot sells multimeters, but doesn't carry replacement fuses.

The fuse section is kind of hard to find. It should be where they sell fuse boxes etc, way far away from where they sell tools (including meters).

In the one I go, it's on the far right corner area, three or two aisles back.
 

Online tom66

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Re: Holy overpriced bs batman
« Reply #30 on: May 10, 2014, 08:05:15 pm »
Monster products are a money maker for both Monster and the retail shop.
http://consumerist.com/2008/02/08/monster-cables-monster-ripoff-80-markups/
 

Offline GreyWoolfe

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Re: Holy overpriced bs batman
« Reply #31 on: May 10, 2014, 10:53:42 pm »
I would say that whatever type of fuse is in it, replace with like, regardless of cost.  Upgrading to the HRC fuses probably isn't a bad idea and may work out cost wise in the long run.
"Heaven has been described as the place that once you get there all the dogs you ever loved run up to greet you."
 

Offline miguelvp

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Re: Holy overpriced bs batman
« Reply #32 on: May 11, 2014, 12:28:21 am »
I would say that whatever type of fuse is in it, replace with like, regardless of cost.  Upgrading to the HRC fuses probably isn't a bad idea and may work out cost wise in the long run.

He has a UNI-T 71 series as I do, the manual specifies just what I told him to get. 0.5A, 250V, fast type fuse 5x20mm.
 

Offline Tinkerer

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Re: Holy overpriced bs batman
« Reply #33 on: May 11, 2014, 01:07:19 am »
just wrap some aluminum foil around it and replace in the slot.  should be good for the next 1000 years.

(is he serious?  that's up to you to guess.)
In all seriousness, you could use a piece of wire(or in this case foil) to act as a fuse based on the fusing current of the size and material. Just that once it melted you would have little metal droplets laying around instead of contained.
Heres an interesting chart because I was curious: http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/wirefusing.pdf

I myself have a UNI-T 61E. I also have a crap meter to use if I am worried that I may have made a mistake in knowing how much power something has.(if its something that might be powerful enough to blow up a meter instead of blowing a fuse/simply frying it, then I will take safety first)
 

Offline Stonent

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Re: Holy overpriced bs batman
« Reply #34 on: May 11, 2014, 03:34:52 am »
I refused to pay RadioShack $3 for a 200ma fuse for my meter. So I ordered a 10 pack from China for $1
The larger the government, the smaller the citizen.
 

Offline saturation

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Re: Holy overpriced bs batman
« Reply #35 on: May 11, 2014, 02:48:55 pm »
If you bought it from eBay I'd sacrifice a few of those fuses and test they actually open at ~ 200mA.  Many fuses I've tested from friends do not blow at the rated amps. 


I refused to pay RadioShack $3 for a 200ma fuse for my meter. So I ordered a 10 pack from China for $1
Best Wishes,

 Saturation
 

Online madires

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Re: Holy overpriced bs batman
« Reply #36 on: May 11, 2014, 02:59:54 pm »
I refused to pay RadioShack $3 for a 200ma fuse for my meter. So I ordered a 10 pack from China for $1

Wow, $3 for a standard fuse. A pack with 10 glass fuses from ESKA costs €0.70 at a local internet shop.
 

Offline KJDS

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Re: Holy overpriced bs batman
« Reply #37 on: May 11, 2014, 03:04:46 pm »
A 200mA fuse should conduct 200mA continuously

http://www.littelfuse.com/~/media/electronics/datasheets/fuses/littelfuse_fuse_201p_datasheet.pdf.pdf

The graph on page two shows that for a fuse to blow in 1 second takes about 2 to 5 times the rated current.

Running at 1.4x rated current and you'll have a very long wait indeed.




If you bought it from eBay I'd sacrifice a few of those fuses and test they actually open at ~ 200mA.  Many fuses I've tested from friends do not blow at the rated amps. 


I refused to pay RadioShack $3 for a 200ma fuse for my meter. So I ordered a 10 pack from China for $1

Offline saturation

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Re: Holy overpriced bs batman
« Reply #38 on: May 11, 2014, 04:13:51 pm »
Yes, meant more at rated amps as per spec sheet.  We know fuses are rated to pass the 'labeled' current but how long depends on type, from many hours to indefinitely.  Most DMMs that use glass fuses are fast blow type which is ~ 1.5-2x rated amps, or 300-400mA should be nearly 'instant'.



A 200mA fuse should conduct 200mA continuously

http://www.littelfuse.com/~/media/electronics/datasheets/fuses/littelfuse_fuse_201p_datasheet.pdf.pdf

The graph on page two shows that for a fuse to blow in 1 second takes about 2 to 5 times the rated current.

Running at 1.4x rated current and you'll have a very long wait indeed.




If you bought it from eBay I'd sacrifice a few of those fuses and test they actually open at ~ 200mA.  Many fuses I've tested from friends do not blow at the rated amps. 


I refused to pay RadioShack $3 for a 200ma fuse for my meter. So I ordered a 10 pack from China for $1
Best Wishes,

 Saturation
 

Offline XOIIO

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Re: Holy overpriced bs batman
« Reply #39 on: May 11, 2014, 05:06:30 pm »
I'm curious, are there any multimeters that go above 400ma before switching to amps range? It kind of seems like there might be some that go up to one amp, but maybe it's a limitation of what's used to measure more accurately?

Offline nerdyHippy

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Re: Holy overpriced bs batman
« Reply #40 on: May 12, 2014, 12:33:27 am »
the POS system displayed the cost
I find that hard to believe; why would they have that info available to cashiers?
 

Offline XOIIO

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Re: Holy overpriced bs batman
« Reply #41 on: May 12, 2014, 12:39:36 am »
the POS system displayed the cost
I find that hard to believe; why would they have that info available to cashiers?

Depends if the store operated independently/the software they used, I worked at a local PC shop and when I ran the till as well as adding inventory I had full access to the markups and original prices.

Offline Legion

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Re: Holy overpriced bs batman
« Reply #42 on: May 12, 2014, 02:24:40 am »
the POS system displayed the cost
I find that hard to believe; why would they have that info available to cashiers?

I remember it distinctly, since I naively revealed the cost to a customer complaining about the price of an item. "You're right, that is a ripoff! It only cost 35 cents!" My manager was less than impressed.
 

Offline XOIIO

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Re: Holy overpriced bs batman
« Reply #43 on: May 12, 2014, 02:26:01 am »
the POS system displayed the cost
I find that hard to believe; why would they have that info available to cashiers?

I remember it distinctly, since I naively revealed the cost to a customer complaining about the price of an item. "You're right, that is a ripoff! It only cost 35 cents!" My manager was less than impressed.

 :o I can imagine.

Offline TMM

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Re: Holy overpriced bs batman
« Reply #44 on: May 12, 2014, 04:28:22 am »
I'm curious, are there any multimeters that go above 400ma before switching to amps range? It kind of seems like there might be some that go up to one amp, but maybe it's a limitation of what's used to measure more accurately?
Fluke 87V goes up to 600mA and the fuse lasts minutes up to several amps iirc. Limitation is the range of the ADC.
 

Offline XOIIO

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Re: Holy overpriced bs batman
« Reply #45 on: May 12, 2014, 07:54:58 pm »
Yup, phoned in, they are sold in packs of 5, and still will cost less than a fiver.

Online mzacharias

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Re: Holy overpriced bs batman
« Reply #46 on: May 24, 2014, 09:04:51 pm »
The Tektronix TX-3 and at least a couple Gossen models use mosfets to seamlessly switch from microamps straight through to their higher amp range, using only their three input jacks.
 


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