in line fuse holder

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tragwag
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in line fuse holder

Post: # 44171Unread post tragwag
Thu Sep 29, 2016 4:34 pm

I just wanted to post about my experience a little bit with an inline fuse holder,
I know there's a bunch of threads that mention to get one, but here's what I've found trying to outfit my 6N with an inline fuse holder.

the radioshack kind was really faulty for me, cost around $10-15, and had an intermittent connection.

I posted a photo of the vinyl recorder fuse holders, and a friend helped me identify it as this: Blugin FX0380
http://www.mouser.com/Search/m_ProductDetail.aspx?Bulgin%2FFX0380%2F&qs=sGAEpiMZZMuxTAA0eeO5G6EyPAkh0XCYT%2FTVuhEJrUw%3D

definitely what I would suggest, hope this helps in a slightly more specific way.
making lathe cuts on a Presto 6N, HIFI stereo cuts on vinylrecorder
at Audio Geography Studios, Providence, RI USA
http://www.audiogeography.com

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Gridlock
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Re: in line fuse holder

Post: # 44172Unread post Gridlock
Thu Sep 29, 2016 5:01 pm

I really wish there were a list or way to properly decide which volt quick fuse to use for what heads and ohms and stuff. .5 was too low for my head (audax 4Ω?)
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Recordette Sr.......Presto K-8

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sameal
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Re: in line fuse holder

Post: # 44174Unread post sameal
Thu Sep 29, 2016 11:18 pm

I quit buying radio shack fuse holders awhile back. They fall apart out of the pack. Radio shack 1/4 jacks are garbage as well. They didn't make much you could trust in their later years.

I get them from auto parts stores in a pinch, but mostly just rob them out of dead electronics.

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opcode66
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Re: in line fuse holder

Post: # 44182Unread post opcode66
Fri Sep 30, 2016 5:54 pm

The value of the fuse depends on a the Resistance (and to some extent the impedance) of the coil. So, different mono heads are wound to different Impedances (dc resistance values). Running the same voltage over heads of different resistance will allow more or less current to flow. This is a problem for small tightly packed coil footprints due to heat buildup. Others not so much. So, physical design of the coil and the housing is also a consideration.

0.5 is simply a default safe value. Your mileage may vary.

Final note, it isn't terribly difficult to make an analog circuit breaker where the acceptable amperage is determined by a trimmer you can calibrate. The analog circuit opens a normally closed relay. A button provides a means to reset the circuit. This avoids the need to have fuses. And, allows you to set the value discretely. Last I checked, 0.75 amps is not a commonly made fuse value. That may be ideal for you.

Professional cutting system have this sort of circuit breaker independently on both left and right channel. No fuses. Just high quality relays. Neumann's are magnesium filled I believe. Flo is also offering or at least posting images and a description of something similar.

Hope this is useful information.
Cutting, Inventing & Innovating
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tragwag
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Re: in line fuse holder

Post: # 44226Unread post tragwag
Tue Oct 04, 2016 1:21 pm

opcode - that's good info, I do remember seeing that 'circuit breaker' type of system on the SAL rack, definitely a good innovation.

in other news, I did find this chart posted by soulbear on another thread regarding an inline fuse:
the thread:
http://lathetrolls.com/viewtopic.php?f=1&t=6740&p=43989&hilit=fuse#p43989

the chart (attached)
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making lathe cuts on a Presto 6N, HIFI stereo cuts on vinylrecorder
at Audio Geography Studios, Providence, RI USA
http://www.audiogeography.com

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sameal
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Re: in line fuse holder

Post: # 44232Unread post sameal
Tue Oct 04, 2016 6:14 pm

Does anybody have a schematic?

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sameal
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Re: in line fuse holder

Post: # 44234Unread post sameal
Tue Oct 04, 2016 9:36 pm

..........of the circuit breaker obviously. I think i got the inline fuse!

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Soulbear
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Re: in line fuse holder

Post: # 44236Unread post Soulbear
Wed Oct 05, 2016 5:42 am

Hi There,
tragwag wrote:in other news, I did find this chart posted by soulbear on another thread regarding an inline fuse:
the thread:
I've also posted these Charts and Tables too, they're an ideal reminder of ways in which to calculate whichever unknown you may be looking for. Simply stick into whatever of the Formulae, the Parameters that are known. Sometimes you may need to use more than one of these Formulae, to find a "Different" unknown, before you can then input this value, into one of the other Formulae, to find the value that's of real interest to you. Easy Peasy :-
Ohms Law Pie Chart1.jpg
Ohms Law Table.gif
Gridlock wrote:I really wish there were a list or way to properly decide which volt quick fuse to use for what heads and ohms and stuff. .5 was too low for my head (audax 4Ω?)
This is an Hypothetical Calculation using either of the above Chart or Tables, and therefore may not reflect the true Power Handling of your Audax Cutterhead, it is purely an example. You know that your Audax Head is 4 Ohms, assuming it is 2 Watts Power Handling, to find the Amp Value for Fuse Protection, can you now see, you'd simply need to find the Root of 2Watts/4Ohms = Root 0.5 = 0.707 Amps. Ohms Law doesn't tell Fibs, and is a "Stickler" for exactitude, so now you know why your 0.5Amp Fuse was Popping. Fuses of 630 milliamp and 800milliamp are readily available (I know because I have some of both types) I'm sure if you did a thorough search, you'd get even closer to the ideal value.
Regards :wink: :P :D Soulbear
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Soulbear
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Re: in line fuse holder

Post: # 44248Unread post Soulbear
Thu Oct 06, 2016 6:02 am

Hi There,
P.S.
Gridlock wrote:I really wish there were a list or way to properly decide which volt quick fuse to use for what heads and ohms and stuff. .5 was too low for my head (audax 4Ω?)
Soulbear wrote:This is an Hypothetical Calculation using either of the above Chart or Tables, and therefore may not reflect the true Power Handling of your Audax Cutterhead
More likely that your Audax is rated at 1 Watt Power Handling, as it seems Presto's and suchlike of this "Vintage", were as often as not, rated "Closer" to this value. Using this value in the same formula and finding the Root of 1Watt/4 Ohms = Root 0.25 = 0.5Amps. As you've found, this is marginal, given that you've been Popping those 0.5Amp Fuses, and this probably the reason why.
opcode66 wrote:The value of the fuse depends on a the Resistance (and to some extent the impedance) of the coil
As Opcode66 quite rightly points out, Coils of a different value will have a "Different" Current Draw. Again using the same Formula for a 1Watt x 8 Ohm Cutterhead we'd end up with Root of 1Watt/8 Ohms = Root 0.125 = 0.353Amps and not the 0.5Amps for the 4 Ohm Cutterhead. Having done this calculation for my "Ugly Duckling" 500 Ohm Cutterhead, and which was initially given a 2Watt rating by myself, I found I needed a 0.063Amp Fuse inserted into the Audio Line to protect it. In light of what I've just said about "Vintage" Cutterheads being rated around 1Watt, and realising I may have somewhat "Over Estimated" the Power Handling of my own "Ugly Duckling" Cutterhead. I have now re-visited my initial "Calculation" and "De-Rated" it to 1Watt and will fit an even "Lower" value Fuse to protect its Coil. I've now got it calculated to 0.044Amps so will now order some 50milliamp Fuses. I'm thinking that being within around 10% of its rating should be OK for protecting Ugly Duckling's Coil, though I may additionally order some 30milliamp Fuses as well, just to see how they perform. Thanks for raising this Topic Guys, (What a Marvelous Forum Te He!!). You just may just have saved me the "Costs of a "Premature Coil Re-wind" and having to send "Ugly Duckling" off to visit a certain Gentleman in California Te He!!
Regards :wink: :P :D Soulbear

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Soulbear
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Re: in line fuse holder

Post: # 44330Unread post Soulbear
Wed Oct 12, 2016 12:43 pm

Hi Trolls,
Soulbear wrote: I have now re-visited my initial "Calculation" and "De-Rated" it to 1Watt and will fit an even "Lower" value Fuse to protect its Coil. I've now got it calculated to 0.044Amps so will now order some 50milliamp Fuses. I'm thinking that being within around 10% of its rating should be OK for protecting Ugly Duckling's Coil,
They took some finding, but with nearly a week of "Persistent Rooting About" I've managed to locate some 40milliAmp Fuses. I've now got some on order, so I should be about "Bang-On" with the Overload Protection for My "Ugly Duckling" Cutterhead. I know we're only talking in 10s of milliAmps, but still, the original 63milliAmp Fuse that I'd probably erroneously calculated I needed, was some 57.5% "Stiffer" than what was actually needed. I don't need to point out that this is quite a margin to be out, so I reiterate, Thanks for raising this topic Guys, you may have just saved me some Re-Wind Pain, Te He!!
Regards :wink: :P :D Soulbear

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markrob
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Re: in line fuse holder

Post: # 44332Unread post markrob
Wed Oct 12, 2016 2:59 pm

Hi,

The values you are using seem very small. I've not seen a moving iron head that could only handle 1 watt continuous basis. For example, the Presto 1D has 1.25 Watt OPERATING level with plenty of headroom for program peaks (10-12 db). I'd be shocked if it couldn't handle 5-10 watts for an extended period of time. I guess its good to err on the side of caution, but I suspect you will be blowing fuses very easily with a 40ma. fuse in line. Also remember that at just above the rated fuse current, the time to blow is quite long and depends on the fuse type (standard, medium, or fast blow). You should check the chart for the fuse in question to see the approximate times to clear vs. the rating and load currents.

Mark

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Soulbear
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Re: in line fuse holder

Post: # 44333Unread post Soulbear
Wed Oct 12, 2016 3:33 pm

Hi Mark,
Thanks for the input, I thought I'd read somewhere in a Presto 1D Cutterhead Manual that 5.5cm/sec @1K Hz was achieved with 0.6Watts. In light of this, I thought I'd been a little "Over Generous" in estimating that my "Ugly Duckling" Cutterhead's Rating was 2Watts. As you say, I may be erring too much on the side of caution, and find that in order to acheive a decent Recording Level, I just may have to revise "Upwards" the Fuse Rating. Every day I'm getting that little bit closer, to being able to get some "Hands On" experience of this Cutting Game. I'm hoping I don't damage the Coil, but in the event I do, I've not forgotton your Sage Advice of many moons back, to wind it for 8 Ohm operation. I even went as far as buying some Enamelled Wire, after first converting the A.W.G. you mentioned, to the U.K.s more often supplied S.W.G. Enamelled Wire. I think in this instance it's 30 A.W.G. = 33 S.W.G
Regards Soulbear
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