Fuse Already Blown? - Page 1
Forum section: electronics / testgear

author: brockles
author_rank: Newbie
timestamp: February 04, 2023, 02:32:41 pm
content: Put an old 87V in series with a 4mA DC source and I got no readout, then realised the meter was in AC(default). I'm pretty sure the fuse wasn;t blown prior to this but maybe mistaken. Is it possible by being in AC that it blew the fuse when it was a DC current? I'm convinced the fuse wasn't blown before.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 04, 2023, 02:48:28 pm
content: I don't see how a 4ma source can blow a .44 ampere fuse, regardless of the setting of the meter. Even in "off" mode, the fuse can be blown with too much current, but current lower than the fuse's rating won't.Unless your source is defective or otherwise putting out more than 4 ma.Are you sure the fuse wasn't blown before?

author: brockles
author_rank: Newbie
timestamp: February 04, 2023, 02:54:15 pm
content: Opened up the meter to remember I'd taken out the fuse for another meter a few years agoPlease can someone delete this post

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 04, 2023, 03:25:32 pm
content: I believe you can delete it.You were correct, however. The fuse was not blown, because it wasn't there.

author: themadhippy
author_rank: Super Contributor
timestamp: February 04, 2023, 03:37:59 pm
content: QuoteBut how do you know its not blown in its alternative location?

author: Excavatoree
author_rank: Frequent Contributor
timestamp: February 04, 2023, 04:59:39 pm
content: Quote from: themadhippy on February 04, 2023, 03:37:59 pmThere are many fuses in many locations - some blown and some not. How does one know which fuse is for the meter? Is the the one that was last removed, or the one that will be installed?

author: extremgear
author_rank: Contributor
timestamp: February 04, 2023, 09:41:08 pm
content: Maybe the current was higher than 4ma .Depending of your supply, if it was set to 4ma with a high voltage and then plugged to the meter the current was probably higher than 4 ma during a short time .

author: BillyO
author_rank: Super Contributor
timestamp: February 04, 2023, 10:06:24 pm
content: Quote from: extremgear on February 04, 2023, 09:41:08 pmThe current was 0 the entire time. There was no fuse in the meter.

author: tv84
author_rank: Super Contributor
timestamp: February 04, 2023, 10:17:03 pm
content: You should increase your current source in order to overcome that fuse absence!

author: AVGresponding
author_rank: Super Contributor
timestamp: February 05, 2023, 09:55:03 am
content: Quote from: Excavatoree on February 04, 2023, 04:59:39 pmSchrödinger's Fuse...

author: Gyro
author_rank: Super Contributor
timestamp: February 05, 2023, 11:04:04 am
content: QuoteI don't think Schrödinger considered the 'forgot to put the cat in the box' scenario.

author: AVGresponding
author_rank: Super Contributor
timestamp: February 05, 2023, 01:17:35 pm
content: Quote from: Gyro on February 05, 2023, 11:04:04 amMaybe he should have!

author: BillyO
author_rank: Super Contributor
timestamp: February 05, 2023, 01:41:10 pm
content: Quote from: AVGresponding on February 05, 2023, 01:17:35 pmMaybe he did.

author: Kean
author_rank: Unknown
timestamp: February 05, 2023, 04:18:02 pm
content: Quote from: tv84 on February 04, 2023, 10:17:03 pmI think that upping the current source compliance voltage sufficiently to jump the distance of the missing fuse is the solution

author: AVGresponding
author_rank: Super Contributor
timestamp: February 05, 2023, 07:55:21 pm
content: Quote from: BillyO on February 05, 2023, 01:41:10 pmSchrödinger's Schrödinger..?