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Old 7th Sep 2020, 7:44 pm   #123
Pinörkel
Pentode
 
Join Date: Jun 2019
Location: Dortmund, Germany
Posts: 161
Default Re: Telequipment D75 scope.

Thank you for the answers. I already figured out that the response time of a fuse at a given current is specified as a quite large interval for different current values, what leads to a min and max graph specification. What got me thinking was that the interval can apparently be very different for fuses of the same type. A 1 A time-delay fuse blowing anywhere from 1 to 5 seconds for 2 A is quite a difference to one blowing anywhere from 10 to 30 minutes at the same 2 A. In many cases the response times get more similar (and much smaller) for higher current values, but I was concerned about the moderate overload situations.
The TDC11 is not a simple wound up wire like other time-delay fuses but has a three component construction. I consists of a fast blowing fuse wire rated for a higher amperage than the actual fuse to ensure fast blowing at really high currents. The second component is a metal with a low melting point and the third one a comparatively high resistance wire that forms a spring and can heat up the low melting point metal, which is then pulled apart by the spring. This allows much better control about the fuse response time at different loads. I just thought, a fuse with a comparatively short response time for moderate overloads may have been chosen for a reason. However, if you say it does not matter, I could try the fuses from my local dealer.
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