Can you please help to identify this smd fuse? - Page 1
Forum section: electronics / repair

author: tlhsglm
author_rank: Contributor
timestamp: July 07, 2022, 12:08:16 pm
content: Hi all,I have to identify this boards components. It is a step motor controller. I stuck on that fuse( I think it is fuse by looking the letter F2).It has no marking letters on it. Solders not included dimensions are 3 mm x 1,5 mm.Can you please give me an idea or track?I think it is working and i will desolder it later but when i done i dont know how to identfy it.https://ibb.co/jRT1JNQhttps://ibb.co/BtK7pv0https://ibb.co/8gq6pF3

author: abdulbadii
author_rank: Frequent Contributor
timestamp: July 07, 2022, 02:01:32 pm
content: try see ahead for max Amp I for Q/D/IC property then match it onhttps://www.mouser.com/pdfdocs/teconnectivitysurfacemountfuses.pdf

author: tlhsglm
author_rank: Contributor
timestamp: July 07, 2022, 09:41:40 pm
content: Quote from: abdulbadii on July 07, 2022, 02:01:32 pmThanks for your reply but kindly i didn't understand "try see ahead for max Amp I for Q/D/IC property" how can i check it?Extra info: I tracked package dimensions it's lenght 3mm width 1.5 mm andheight is 0.60 mm. Most packages does not matching height.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: July 07, 2022, 11:28:13 pm
content: He means try to estimate the amps of the fuse considering what is supplies...Does it supply the motor??? ....then see what amps the motor draws...something like that.

author: tlhsglm
author_rank: Contributor
timestamp: July 08, 2022, 07:53:04 am
content: Quote from: Wallace Gasiewicz on July 07, 2022, 11:28:13 pmThanks for your reply, oh i get it. Also i have to check it's type with oscilloscope right? To understand is it a general fuse or resettable fuse?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: July 08, 2022, 04:13:14 pm
content: Check it for continuity with an Ohmeter. It is not a resetableIf reads very high in the circuit, it is blown.You have to estimate the amperage rating of the new fuse you will install.

author: tlhsglm
author_rank: Contributor
timestamp: July 09, 2022, 02:45:52 pm
content: Okey it is not blown.To estimate amperage rating, I'll see what part it connects to. Then I will look at its datasheet and choose the maximum amperage value, right?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: July 09, 2022, 06:16:27 pm
content: Why replace the fuse if it is not blown???

author: tlhsglm
author_rank: Contributor
timestamp: July 10, 2022, 08:03:37 am
content: Because i want to learn everything in the card and how it is works. It is a card for step motors. I think it will be very beneficial for me to learn and interpret the card of a machine used in the industry in this way.

author: tooki
author_rank: Super Contributor
timestamp: July 10, 2022, 12:30:00 pm
content: A fuse is a protection device, nothing more. To an extent, it doesn’t exist as part of the circuit. Its purpose is as a controlled point of failure if something goes wrong elsewhere.It being unmarked, there’s no way to know what its precise characteristics are. Even destructive testing wouldn’t let you identify it conclusively.I think you’d be better off learning about fuses independently of this, and for the purposes of this circuit, just pretend it’s not there.