Fuse blown indicaor

MaxHeadRoom

Joined Jul 18, 2013
20,898
As per posted in #2, If a neon is placed across the fuse it lights when the fuse is blown, I use this style of fuse holder in present panel building.
Made by BussFuse.
Max.
 
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#12

Joined Nov 30, 2010
18,210
I've done more complicated circuits with a red/green LED, but it was just a design experiment, not an elegant method for a 230 VAC line. A UL approved neon indicator is way simpler and safer than what I did as a curiosity project.
 

Kermit2

Joined Feb 5, 2010
4,162
Indication of a blown fuse at my house always included quiet and darkness. A flashlight and replacement fuse soon brightened the situation.
What kind of 240 volt equipment are you powering that doesn't indicate it has no power and needs a secondary indicator to show it is not working?
 

#12

Joined Nov 30, 2010
18,210
What kind of 240 volt equipment are you powering that doesn't indicate it has no power and needs a secondary indicator to show it is not working?
Meh. Sometimes an idiot light is convenient. I designed 5 idiot lights in my air conditioner so it tells me whether it has a drain problem, a fan motor problem (two motors), or a Freon problem (High pressure safety-out or Low pressure safety-out).
 

rherber1

Joined Jan 6, 2008
26
Hi
how to design 230v fuse blown indicator circuit ?????
please give proper circuit diagram

While the Elektor design does work it is rather old and uses a neon lamp.

I have tested and used the following circuit but with a vital modification.
http://www.eleccircuit.com/fuse-failure-alarm-with-2-led/

As shown the circuit will simply blow up both LEDs when the fuse blows where the load is either stil intact or short circuited (and the latter is the main reason for the fuse to blow in the first place).

It is vital that D3 be moved from its present location to the top of the Green LED (keeping same polarity)
Notes:
The voltage rating of D2 (5.1V zener) is not critical - I used a 6.2V. Also the LEDs can be separate but must be sensitive types since they will have only 2mA or so through them.

My application was to drive a 100W, 220/240V drain pump motor in my washing machine and instead of using a wire fuse I used a Murata PTGL18AR6ROH8B72BO PTC circuit protector and the blown fuse indicator worked well with that.
Here's a circuit from Elektor years ago, neon lights up normally when fuse is ok, and flashes when blown..


http://d3i5bpxkxvwmz.cloudfront.net/resized/images/remote/http_s.eeweb.com/members/extreme_circuits/blog/2013/04/25/61-1366932348_317_212.PNG
 
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