If the item comes direct from a manufacturer, it may be delivered in non-retail packaging, such as a plain or unprinted box or plastic bag. If the fuse is in the loudspeaker circuit, ie, in series with the loudspeaker as a load, then it needs to tolerate occasional overloads, but open on continued overload - so, medium slow blow. While all this discussion on types of fuses is very instructive, I wonder whether it answers the underlying question.

Incidentally, A good design should have F or T plus the fuse rating marked on the PCB where the fuse holder is. He found that a spot (the 'M' spot) of solder on a silver wire element did not affect the short circuit performance, but it did reduce the time to blow on a sustained lower current. Most purchases from business sellers are protected by the Consumer Contract Regulations 2013 which give you the right to cancel the purchase within 14 days after the day you receive the item.

I recently gave a talk to my local amateur radio club on the subject, and what follows is from the script I wrote for that talk. The fuse within a plug is a safety device that is designed to protect the lead rather than the appliance therefore it will blow if the circuit overloads or there is a fault. Read more about the condition New: A brand-new, unused, unopened and undamaged item in original retail packaging (where packaging is applicable).

I was an electrical engineer in the 1950s, part of my work was concerned with testing and selecting fuses. There are many variations on this design and it gives manufacturers a lot of parameters for adjusting the fuse characteristics.A problem with this type of fuse is that occasional currents just above the rated value may cause some unwanted diffusion to occur, altering the fuse characteristics without visible change. This, with suitably chosen alloys, nicely gives the characteristic needed for a surge resistant fuse. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. If the fuse is in the mains input lead before any power supply unit, then it needs to sustain the start-up current required to charge the main filter capacitors - so, slow blow.

If the fuse is in series with a transistorised power supply's pass transistor, then it needs to be a very fast blow. Occasionally, as in the image above, a by-pass wire across the spring is used to adjust the characteristics of the fuse. I have a potterton assure 30 combi boiler, 3 years old which has stopped working due to it blowing an internal fuse. The 103 third parties who use cookies on this service do so for their purposes of displaying and measuring personalized ads, generating audience insights, and developing and improving products.

The slow blow fuse has "thermal inertia" whereas a fast blow has a very short thermal time constant. Packaging Close Λ After unpacking, carefully inspect the various random accessories and parts in the package to avoid omissions. Everyday items at home or in the office use these products to function, it is important replacements are always to hand.

New: A brand-new, unused, unopened and undamaged item in original retail packaging (where packaging . If fast-blow is used instead of slow-blow, there will be no damage, but fuse consumption can increase, which is usually preferable to equipment damage. The combination of lump and spring, with its relatively high thermal mass, also allows the surge to pass, but provides the protection for longer term but lesser overloads.To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data.