Author Topic: Hakko hasn't heard of fuse holders?  (Read 6347 times)

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Offline lpc32

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Hakko hasn't heard of fuse holders?
« on: July 07, 2015, 06:13:15 pm »


What's the idea of axial fuses anyway?

And by the way, how come it's 2A for 125V rated, but only 0.63A for 250V?
 

Offline Neilm

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Re: Hakko hasn't heard of fuse holders?
« Reply #1 on: July 07, 2015, 06:26:35 pm »
I have seen fuses directly soldered to the PCB before now, but that was due to the size of the fuse as it was for 10A operation and needed a very low resistance. Soldering the fuse in reduced  the fuse resistance and lowered the fuse so it would fit in the space envelope.
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Offline electr_peter

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Re: Hakko hasn't heard of fuse holders?
« Reply #2 on: July 07, 2015, 06:52:45 pm »
Most likely cause is space saving. Adding fuse holder adds width, height, depth, mass, obstructions, holes. Also, manufacturer should take into account a need to be easily replace fuse. Requirements for extra space and complexity add up fast.
 

Offline lpc32

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Re: Hakko hasn't heard of fuse holders?
« Reply #3 on: July 07, 2015, 06:54:12 pm »
I don't think space or resistance concerns are an issue in the FX-888D and similar?
« Last Edit: July 07, 2015, 06:56:24 pm by lpc32 »
 

Offline SeanB

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Re: Hakko hasn't heard of fuse holders?
« Reply #4 on: July 07, 2015, 07:06:40 pm »
Fuse holder is 2c extra, an as you already have a manual soldering operation on the board the lack of holder is no extra time on clipping it into the 2c holder.

Power rating difference depending on current is standard, though you mostly will get 2A on 125V and 1A on 250V, they must have measured and found the cheaper in volume because it is not a standard integer amp value fuse would survive the switch on surge at least 20 times or at least the initial factory "turn it on, did it blow up, no so ship it" test.
 

Offline nanofrog

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Re: Hakko hasn't heard of fuse holders?
« Reply #5 on: July 07, 2015, 10:33:52 pm »
I don't think space or resistance concerns are an issue in the FX-888D and similar?
Do keep in mind, it's built to meet a low price point, so the BOM is very tight.
 

Offline lpc32

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Re: Hakko hasn't heard of fuse holders?
« Reply #6 on: July 08, 2015, 08:36:36 am »
If price is the reason, color me disappointed. It's not supposed to be a Chinese product built as cheap as possible, and it doesn't cost like one.

SeanB: What, amp rating with a decimal point vs whole number makes a difference?
 
 

Offline lpc32

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Re: Hakko hasn't heard of fuse holders?
« Reply #7 on: July 08, 2015, 08:40:17 am »
Yeah, it's original. They call this fuse board B3722. No fuse holder, and stupidly mounted on top of the transformer by soldered connections, to make the fuse difficult to replace. :)
« Last Edit: July 08, 2015, 08:43:12 am by lpc32 »
 

Offline GoneTomorrow

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Re: Hakko hasn't heard of fuse holders?
« Reply #8 on: July 09, 2015, 02:56:08 am »
I suppose, unlike a DMM, the fuse really shouldn't be blowing in the soldering station. If the fuse blows, something else has gone seriously wrong and you'd probably be repairing that anyway.
 

Offline continuo

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Re: Hakko hasn't heard of fuse holders?
« Reply #9 on: July 09, 2015, 08:20:09 am »
Yeah, if you connect your poor 110V Hakko to 230V mains, such things may happen  ;D

https://www.eevblog.com/forum/repair/hakko-fx-888d-120v-connected-to-230v/
 

Offline SeanB

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Re: Hakko hasn't heard of fuse holders?
« Reply #10 on: July 11, 2015, 09:23:19 am »
If price is the reason, color me disappointed. It's not supposed to be a Chinese product built as cheap as possible, and it doesn't cost like one.

SeanB: What, amp rating with a decimal point vs whole number makes a difference?

Thinner fuse wire, so has to be passed through another diamond die that is not used often in production, so more expensive. 1A wire is almost double the area of a 500mA wire, which can be drawn in a single pass from the 1A wire with the right beeswax lubricant, and which is a popular wire so large volumes. 630mA is in between so the extra step of the 500mA wire but not as common a fuse. they must have gotten a batch from a manufacturer somewhere on the market cheap, and as they found a 500mA fuse blows at switch on every so often, and a 1A one does not, they tried the 630ma one and found it did the same as the 1a, so they saved money off buying the common 1a fuse new.
 

Offline Psi

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Re: Hakko hasn't heard of fuse holders?
« Reply #11 on: July 11, 2015, 10:14:26 am »
I suppose, unlike a DMM, the fuse really shouldn't be blowing in the soldering station. If the fuse blows, something else has gone seriously wrong and you'd probably be repairing that anyway.

the fuse in my 888 blew and i had to unsolder and replace it :(
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline lpc32

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Re: Hakko hasn't heard of fuse holders?
« Reply #12 on: July 12, 2015, 03:51:58 pm »
the fuse in my 888 blew and i had to unsolder and replace it :(
What did you replace it with?

The one I removed (NSF FCT from Nippon Seisen Cable) appears to be a medium/semi time-lag. I can't find any readily available medium speed fuses, just quick/fast, but I'm not sure if the general speed ratings are that meaningful. Depending on the overcurrent range you look at some "fast" fuses are slower than this FCT "medium" fuse, though maybe not in higher currents.

630mA is in between so the extra step of the 500mA wire but not as common a fuse.
So that would make it more expensive rather than cheaper, no? If by chance they found some cheaper stock for 0.63A you wouldn't expect it to become the default type, as indicated on the fuse PCB. But for a 70W station 230V/0.63A is actually closer than 120V/2A, so maybe the 2A is the unexpected one.

BTW, any idea what's that small piece of rubber foam below the PCB for?

« Last Edit: September 19, 2015, 04:03:45 pm by lpc32 »
 

Offline djQUAN

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Re: Hakko hasn't heard of fuse holders?
« Reply #13 on: July 12, 2015, 04:05:49 pm »
Yeah, if you connect your poor 110V Hakko to 230V mains, such things may happen  ;D

https://www.eevblog.com/forum/repair/hakko-fx-888d-120v-connected-to-230v/

Yup. Had that happen to mine. (The first 888 without the "D") After doing my LED mod and decided to test it out, I accidentally plugged it into the 240V outlet on the workbench. Replaced fuse and it worked again. Still using it many years later.
« Last Edit: July 12, 2015, 04:11:11 pm by djQUAN »
 

Offline Jay_Diddy_B

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Re: Hakko hasn't heard of fuse holders?
« Reply #14 on: July 12, 2015, 04:28:08 pm »
Hi,

The real reason is to make you buy another soldering iron, because you need a working one to change the fuse in the broken one.

After all they sell soldering irons.. >:D

Regards,

Jay_Diddy_B
 

Offline Psi

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Re: Hakko hasn't heard of fuse holders?
« Reply #15 on: July 13, 2015, 06:10:53 am »
the fuse in my 888 blew and i had to unsolder and replace it :(
What did you replace it with?
Whatever I had  :-DD
I think i pulled the end caps off and pushed them onto the new fuse
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline Psi

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Re: Hakko hasn't heard of fuse holders?
« Reply #16 on: July 13, 2015, 06:12:06 am »
Hi,

The real reason is to make you buy another soldering iron, because you need a working one to change the fuse in the broken one.

After all they sell soldering irons.. >:D

Regards,

Jay_Diddy_B

You know what, I think your right, I think it was done as a joke
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline lpc32

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Re: Hakko hasn't heard of fuse holders?
« Reply #17 on: July 13, 2015, 09:17:32 am »
Whatever I had  :-DD
I guess you're not planning on tripping the new fuse. :)

The real reason is to make you buy another soldering iron
Well, they failed.
 

Offline amyk

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Re: Hakko hasn't heard of fuse holders?
« Reply #18 on: July 13, 2015, 10:15:30 am »
Even the cheap Chinese hot air stations have the fuse in a holder (although not always connected to the right side of the mains)...
 

Offline lewis

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Re: Hakko hasn't heard of fuse holders?
« Reply #19 on: July 13, 2015, 10:59:12 am »
Here's a little gem from a class D power amplifier:

I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered.
 

Offline Psi

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Re: Hakko hasn't heard of fuse holders?
« Reply #20 on: July 13, 2015, 10:59:14 am »
whats why i think it was done deliberately as a joke
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline lpc32

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Re: Hakko hasn't heard of fuse holders?
« Reply #21 on: July 13, 2015, 08:35:21 pm »
Here's a little gem from a class D power amplifier:

Art?
 

Offline GoneTomorrow

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Re: Hakko hasn't heard of fuse holders?
« Reply #22 on: July 13, 2015, 10:16:24 pm »
the fuse in my 888 blew and i had to unsolder and replace it :(

The question would be why is blew. I'm sure Hakko did the maths to ensure that the fuse is specced to handle all normal conditions, something must have gone funny. I suppose a large voltage spike might cause a blown fuse. I'd be worried about the poor transformers primary winding in that case though.
 

Offline lowimpedance

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Re: Hakko hasn't heard of fuse holders?
« Reply #23 on: July 13, 2015, 11:22:37 pm »
If price is the reason, color me disappointed. It's not supposed to be a Chinese product built as cheap as possible, and it doesn't cost like one.

SeanB: What, amp rating with a decimal point vs whole number makes a difference?

Thinner fuse wire, so has to be passed through another diamond die that is not used often in production, so more expensive. 1A wire is almost double the area of a 500mA wire, which can be drawn in a single pass from the 1A wire with the right beeswax lubricant, and which is a popular wire so large volumes. 630mA is in between so the extra step of the 500mA wire but not as common a fuse. they must have gotten a batch from a manufacturer somewhere on the market cheap, and as they found a 500mA fuse blows at switch on every so often, and a 1A one does not, they tried the 630ma one and found it did the same as the 1a, so they saved money off buying the common 1a fuse new.

 Interestingly the 630mA is the most common value I have  found in domestic electronics of the dvd / video and similar for 240V mains at least.
The odd multimeter or 2 or 3 or 4...or........can't remember !.
 


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