Tag Archives: BFuse

$19 ATtiny25 BFuse hits Tindie

Powered by Atmel’s ATtiny 25 microcontroller (MCU), BFuse is an electronic fuse designed specifically for breadboards.

According to the product’s official Tindie description, the BFuse is fast, adjustable and programmable.

“A lot of mistakes can happen during prototyping: Misplacing components, creating random shorts or simply making things wrong,” BFuse creator Kaktus explained. 

”BFuse can help saving precious components that would otherwise be damaged by such mistakes. It works like a regular fuse, only better.”

So, how exactly does the board work? Well, BFuse continuously compares the load current with the value set by the trimmer. Meaning, If an overcurrent occurs, BFuse disconnects the load by switching off a P-channel MOSFET – notifying the user by lighting a red LED. Meanwhile, a green LED confirms when the load is connected.

“Even though the fuse is designed for operations up to 1A, it can measure current up to 5A, giving you options to allow for some inrush current for capacitive loads. BFuse is powered by the same line it protects, no extra power needed,” Kaktus concluded.

“BFuse not only protects against overcurrent but it has also built-in reverse polarity protection. Moreover, it has a transient-voltage suppressor on both its input and output. BFuse was tested on a 22-Amp Statron stabilized power source for short-circuit and startup into short-circuit – it passed with flying colors.”

Aside from Atmel’s ATtiny 25 microcontroller, key technical specs include:

  • Input voltage range: 3.3–12V (absolute maximum rating 3–13V)
  • Measured current range: 5A
  • Trip current range: 50mA–1A
  • Fuse resistance: less than 100 milliohm
  • Fuse power consumption: less than 10mA
  • Dimensions: 18×36mm
  • Weight: 4.5 grams

Note: BFuse is shipped as a kit, so Makers and engineers will have to solder the pin headers: 4 pins for the power line (input/output) and 6 pins for the SPI header (to re-program BFuse).

Interested in learning more? You can check out the official BFuse Tindie page here.