Why Efuse

Your high quality Hi-Fi devices deserve better than a thin copper wire. Equip them today with an EFUSE and experience the best possible protection and an incomparable sound reproduction.

Conventional fuses and their disadvantages

Almost all Hi-Fi systems use conventional fuses to protect equipment from being damaged when a fault causes overcurrent. These fuses are usually a thin wire encased in glass that overheats and melts when exposed to overcurrent. This means that all the power consumed by the equipment has to flow through this thin wire – and that has clearly audible consequences due to the high resistance of the thin wire in the fuse. Another major disadvantage of conventional fuses is their relative lack of precision when blowing. According to industrial standards, a fuse must operate, or blow, within a specified period of time when exposed to 10-times its rated current (around 0.2 seconds in the case of a slow-blow fuse).
However, when, for example, using a 1A fuse for a maximum power consumption of 230 W with a mains voltage of 230 V, this means that 2,300 W of power could be consumed before the fuse operates and blows. That is equivalent to the power consumption of a fan heater.
The heat thus generated can cause serious damage to equipment. It is also entirely possible that a lower overcurrent could flow through the system for a longer period of time (several minutes up to a few hours) without blowing a standard fuse.
The graph opposite illustrates this correlation. It shows the maximum disconnection time of a conventional fuse with a rated current of 1A compared to the disconnection behaviour of our EFUSE electronic fuse. For example, in the case of the conventional fuse (red curve), the disconnection time at 1.5-times the rated current is more than 16.6 minutes. This shows the huge advantage of the EFUSE (blue curve), which identifies this same level of overcurrent and disconnects the current flow within 0.1 seconds, thereby protecting the connected device from damage.

The benefits of the EFUSE electronic fuse

If you were to replace the conventional fuse in your equipment with a solid metal pin, you would immediately notice a significant improvement in the quality of music playback. However, doing that would also eliminate the main safety element protecting your device from potentially serious consequences if a fault occurs. This is where the EFUSE comes in – it resolves precisely this dilemma. When using the external version of EFUSE, you start off by replacing the conventional fuse with a solid, low-resistance pin made of rhodium-plated OFC copper. The next step is to use the cable with the integrated external EFUSE to connect your device to the power supply.

Compared to a conventional fuse, the EFUSE exhibits minimal electrical resistance, which results in much more detailed playback – a difference you really can hear. If a fault occurs, the EFUSE immediately interrupts the current flow, thereby protecting your equipment from further damage. Indeed, there is another advantage to the EFUSE besides significantly better playback. Since it deactivates connected devices much faster and more precisely, your valuable equipment benefits from much wider protection. That is not the case when using a conventional fuse.

To accommodate the current consumption of the connected device, the switching threshold of the EFUSE is set to a fixed rated value between 0.5 and 6.0 A. When tripped by a fault in the device, the EFUSE remains in a blocked, inactive status until it is reactivated by pressing the reset button. In other words, the EFUSE does not need to be replaced, just reset. A two-colour LED shows the operating status of the unit.

Operating current is fed to the connected device through a high-quality, gold-plated grounding-type plug (German domestic standard) and connector designed for use with low-temperature devices (IEC standard). Generously dimensioned, high quality and shielded cables also ensure minimal contact resistance, while the shielding of the cable also protects against unwanted interference.