Fixing a laboratory DSC

[stj]

Re: Fixing a laboratory DSC

lamps in parallel will allow more current.
lamps in series are pointless unless they are the wrong voltage.
i mentioned 2 in series because i thought you were going to do it with the 240v side and being canadian your lamps are 120v

and dont give it 6a or a fault could cause a fire.
if you disconnect the load from the power supplies then 1a should be more than enough to get them started.
which is unlikely because we are searching for a fault!

[vrasp]

Re: Fixing a laboratory DSC

I had to go back to reading on electricity basics but I think I understand the use of lamp bulbs as a current limiter.

The part I have a hard time understanding is the number of bulbs to use. If I want to test the device that takes in 6A at 230v, wouldn't the one bulb at 1A be super bright? Then I wouldn't be able to tell if it's bright due to a short or if It's normal.

Same with the other device that runs at 2A 230v. Wouldn't just one bulb be super bright even if there is no short?

[eccerr0r]

Re: Fixing a laboratory DSC

Well the example did not indicate what the device under test (DUT) is represented by - it's just generic behavior of the circuit. The DUT could have been either the parallel or single bulb in series. So yes if you hook up two in parallel and treat the singleton one as the DUT you can see that the DUT will need to pass more current and is indicated by such as it'll burn brighter.

That being said you don't want to allow 6A to go through continuously which is what will happen if you hook up a lot of bulbs in parallel. You only want only one or a few to start off to find "obvious" or critical shorts and then increase them as your confidence that the short has been solved.

[sam_sam_sam]

Re: Fixing a laboratory DSC

One note KTK-R-1 is a faster blowing than a KTK-1 fuse

There are cheaper fuses if you do not need 600 volt voltage rating

I once troubleshooted a machine that was blowing fuses on the controls circuit used the incandescent light
( 100 watt ) bulb instead of the the fuse to find the short in this machine if your light bulb is very bright and you only have a one to two amp fuse in this circuit then you definitely have an issue with the this circuit

[vrasp]

Re: Fixing a laboratory DSC

Thanks guys. It s much clearer. I think I ll be using that bulb method much more often from now on.

[sam_sam_sam]

Re: Fixing a laboratory DSC

Here is where you can find a cheaper fuse series

https://www.amazon.com/Littelfuse-BL.../dp/B07DSPZPX7

[vrasp]

Re: Fixing a laboratory DSC

Here is where you can find a cheaper fuse series

https://www.amazon.com/Littelfuse-BL.../dp/B07DSPZPX7

Thanks I ll have a look.