DoesThis Exist? Thermally Coupled Fuses

I dont know of a way to do it thermally -- are you sure you want to deliberatly burn something ?? but plenty of ways to do it electronically

NC thermal switch driving a relay ?? relay inline on B driven by A.. i.e. when A blows, it interrupts the current to the coil, opening the relay on B ??

Use 2 breakers ganged ??

dont know what the A circuit has on it -- a little more info pls ??

Could you use a striker fuse? They have a shaft that pushes out when the fuse blows, that shaft usually is used to activate a microswitch.

Aim it at the other fuse's fuseholder, to pop it out when the first one blows. ;-)

Cheers! Rich

I'm just curious if such a nonresettable fuse exists.. It might be a part that could exist but is not in production. If it does exist...it probably would be about 5mmx10mm in size and be slow blow. I just came up with the idea while working on some failsafe circuits. D from BC

wow...that's something I haven't heard of...

However..I forgot to mention in my OP that small size is of interest. Small like those fuses that look like resistors.. Also a 1A to 5A rating... D from BC

lol D from BC

Have the 1st circuit fire a scr that blows the 2nd fuse.

You might be able to do something like that with polyswitches. I think Raychem has some notes in thermally coupling them to improve parallelism. You'd have to experiment find what happens to the trip point, these are thermal devices so coupling them to another thermal mass will raise the trip point. I'm not sure I'd want to use it for significant voltage isolation, you'd need to check voltage isolation and worry about lead isolation.

Robert

I wonder if that could get tricky if one needed lots of isolation between the cct with fuse 1 and the cct with fuse 2. D from BC

Use gunpowder or an azide for that ignition and burning...

trigger the scr with an optocoupler on most scr's Vgt is less than 1volt.

SCR = 'solid combustible rocket' ummmm OKay...please post on youtube.

In the telephony world there are fuses which have a spring loaded plunger which is retained by the fuse wire in normal operation. When the fuse is ruptured due to overload the plunger is released to operate a contact which can then b used to initiate an alarm. You could use this alarm contact to perform any desired action subsequent to the fuse operating. Many different manufacturesrs will have their own designs and styles but here is the pdf for one type from a Japanese manufacturer;

A Photoscr (4n39) or a phototriac would give you isolation. Try Vishay, they may even have appnotes on what you're trying to accomplish.

Could you use a striker fuse? They have a shaft that pushes out when the fuse blows, that shaft usually is used to activate a microswitch.

"D from BC" <

You just have to get a couple of fuses that are paid up members

of the " Amalgamated Fuse and Circuit Breakers Union " .

This is their motto :

" One Out - All Out "

...... Phil

Does that mean that cams and gears and belcranks and linkages and solenoids, all connected together to operate a 5 pound rubber mallet to smash the other fuse when the first one blows, are out? :-)

But seriously - can you gate the supply to the second fuse with a mosfet only when voltage is available from the first fuse?

Ed

A thermally coupled dual "mini" nonresettable fuse might be useful to totally isolate a load if there's too much current. When this would be needed...I dunno..but I'm trying to figure an application. If this complete load isolation can be done with semi's ...great..! I should mention that I'm not looking for a solution but looking for a seemingly imaginary part. D from BC

I've seen fuses that operate a switch when they blow.

But, if you're wanting the fuses to blow when the sum of currents exceeds some limit, that won't work for you.

Bye. Jasen

Rube Goldberg lives!