element14 Community
element14 Community
    Register Log In
  • Site
  • Search
  • Log In Register
  • About Us
  • Community Hub
    Community Hub
    • What's New on element14
    • Feedback and Support
    • Benefits of Membership
    • Personal Blogs
    • Members Area
    • Achievement Levels
  • Learn
    Learn
    • Ask an Expert
    • eBooks
    • element14 presents
    • Learning Center
    • Tech Spotlight
    • STEM Academy
    • Webinars, Training and Events
    • Learning Groups
  • Technologies
    Technologies
    • 3D Printing
    • FPGA
    • Industrial Automation
    • Internet of Things
    • Power & Energy
    • Sensors
    • Technology Groups
  • Challenges & Projects
    Challenges & Projects
    • Design Challenges
    • element14 presents Projects
    • Project14
    • Arduino Projects
    • Raspberry Pi Projects
    • Project Groups
  • Products
    Products
    • Arduino
    • Avnet Boards Community
    • Dev Tools
    • Manufacturers
    • Multicomp Pro
    • Product Groups
    • Raspberry Pi
    • RoadTests & Reviews
  • Store
    Store
    • Visit Your Store
    • Choose another store...
      • Europe
      •  Austria (German)
      •  Belgium (Dutch, French)
      •  Bulgaria (Bulgarian)
      •  Czech Republic (Czech)
      •  Denmark (Danish)
      •  Estonia (Estonian)
      •  Finland (Finnish)
      •  France (French)
      •  Germany (German)
      •  Hungary (Hungarian)
      •  Ireland
      •  Israel
      •  Italy (Italian)
      •  Latvia (Latvian)
      •  
      •  Lithuania (Lithuanian)
      •  Netherlands (Dutch)
      •  Norway (Norwegian)
      •  Poland (Polish)
      •  Portugal (Portuguese)
      •  Romania (Romanian)
      •  Russia (Russian)
      •  Slovakia (Slovak)
      •  Slovenia (Slovenian)
      •  Spain (Spanish)
      •  Sweden (Swedish)
      •  Switzerland(German, French)
      •  Turkey (Turkish)
      •  United Kingdom
      • Asia Pacific
      •  Australia
      •  China
      •  Hong Kong
      •  India
      •  Korea (Korean)
      •  Malaysia
      •  New Zealand
      •  Philippines
      •  Singapore
      •  Taiwan
      •  Thailand (Thai)
      • Americas
      •  Brazil (Portuguese)
      •  Canada
      •  Mexico (Spanish)
      •  United States
      Can't find the country/region you're looking for? Visit our export site or find a local distributor.
  • Translate
  • Profile
  • Settings
Power & Energy
  • Technologies
  • More
Power & Energy
Forum Why did my 10A fuse blow?
  • Blog
  • Forum
  • Quiz
  • Documents
  • Polls
  • Events
  • Mentions
  • Sub-Groups
  • Tags
  • More
  • Cancel
  • New
Actions
  • Share
  • More
  • Cancel
Forum Thread Details
  • State Verified Answer
  • Replies 10 replies
  • Answers 2 answers
  • Subscribers 287 subscribers
  • Views 4111 views
  • Users 0 members are here
  • fuse
  • dc power supply
  • switch
Related

Why did my 10A fuse blow?

be.mihai22
be.mihai22 over 7 years ago

Hello everyone!

 

I had a really strange incident yesterday. I was playing a game on my desktop PC yesterday and suddenly I heard something blowing up from my computer.

 

The control panel went off for all sockets in the house. Moreover, the 10 Amp fuse from my power supply power cord blew too.. Unfortunately that was not everything.

 

I changed the fuse and tried again. Nothing. I disassembled my power source, shorted all capacitors to make sure I don't fry my fingers and while doing so, I saw a black piece of silicone falling of. Little did I know it was from an AC/DC Off-line switch.

After visual analysis it was clear, the switch blew and left smoke on the nearby components.

 

I took of the switch today and I am expecting a new one from farnell in a few days.

 

My question is: How did this happen? Is it because I had a 10Amp fuse for a 750W power supply and there was a high current from outside which blew it up... or... the other way around?

 

Thank you in advance.

  • Sign in to reply
  • Cancel

Top Replies

  • jw0752
    jw0752 over 7 years ago +3 suggested
    Hi Mihai, The most likely culprit was poor contacts in the switch itself. Poor contacts equal resistance. Voltage across resistance means heat which just makes the poor contact situation worse. Over time…
  • jw0752
    jw0752 over 7 years ago in reply to be.mihai22 +1 suggested
    Hi Mihai, Your power analysis is good. One consideration on choosing a proper fuse is that many power supplies have a higher current draw as they turn on. This is caused by capacitors which have to charge…
Parents
  • jw0752
    0 jw0752 over 7 years ago

    Hi Mihai,

    The most likely culprit was poor contacts in the switch itself. Poor contacts equal resistance. Voltage across resistance means heat which just makes the poor contact situation worse. Over time the materials that are supposed to insulate the power leads from one another carbonize and become resistors themselves. When enough heat is produced to vaporize some of the carbonized material an arc of electricity will bridge the two power wires and the heat and high current will blow fuses and create a small blast mark on surrounding circuitry. The good news is that this seldom does any damage to the rest of the circuit. You may have to repair the circuit board if it was damaged. All blacken material must be removed. Sometimes epoxy can be used to fill in holes and gaps.

    John

    • Cancel
    • Vote Up +3 Vote Down
    • Sign in to reply
    • Verify Answer
    • Reject Answer
    • Cancel
  • 14rhb
    0 14rhb over 7 years ago in reply to jw0752

    A nice explanation, thanks.

     

    It is good to know the actual mechanism of why something has failed as it gives confidence when replacing that part (and often spurs me to get a good quality make replacement).

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
Reply
  • 14rhb
    0 14rhb over 7 years ago in reply to jw0752

    A nice explanation, thanks.

     

    It is good to know the actual mechanism of why something has failed as it gives confidence when replacing that part (and often spurs me to get a good quality make replacement).

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • Verify Answer
    • Cancel
Children
No Data
element14 Community

element14 is the first online community specifically for engineers. Connect with your peers and get expert answers to your questions.

  • Members
  • Learn
  • Technologies
  • Challenges & Projects
  • Products
  • Store
  • About Us
  • Feedback & Support
  • FAQs
  • Terms of Use
  • Privacy Policy
  • Legal and Copyright Notices
  • Sitemap
  • Cookies

An Avnet Company © 2025 Premier Farnell Limited. All Rights Reserved.

Premier Farnell Ltd, registered in England and Wales (no 00876412), registered office: Farnell House, Forge Lane, Leeds LS12 2NE.

ICP 备案号 10220084.

Follow element14

  • X
  • Facebook
  • linkedin
  • YouTube