"Fuseless fuses?"

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PetrosA

PetrosA

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Lancaster, Pennsylvania
I was reading an article tonight about some employee of a high end car dealer in NYC who crashed a customer's $1,000,000 Koenigsegg sports car. While reading about the manufacturer on Wikipedia, I noticed that one version has an "electronic control unit... without physical fuses."

Is there some kind of equivalent in the real world of non-million dollar sports cars? It sounds like that kind of electronic system would allow us to choose amperage, cutout time, GFI/AFI performance, etc all without changing or even using breakers - just a nice clean panel with 80/160 terminals and a keypad ;)
 
PetrosA said:
I was reading an article tonight about some employee of a high end car dealer in NYC who crashed a customer's $1,000,000 Koenigsegg sports car. While reading about the manufacturer on Wikipedia, I noticed that one version has an "electronic control unit... without physical fuses."

Is there some kind of equivalent in the real world of non-million dollar sports cars? It sounds like that kind of electronic system would allow us to choose amperage, cutout time, GFI/AFI performance, etc all without changing or even using breakers - just a nice clean panel with 80/160 terminals and a keypad ;)
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Wouldnt a fuseless fuse, just be a circuit breaker?

~Matt
 
electronic fusless fuses have been around for years.

It is nothing more then electronic current limiting circuit, I have several 13.6 volt power supply's that have this feature on the output, also almost all 110 volt inverters have this feature built in, if you over load them they will hard off, but will soft back on slowly great for motor loads.;)
 
hurk27 said:
electronic fusless fuses have been around for years.
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I was gonna say the same thing. I've even seen articles in magazines such as Popular Electronics for building such circuits, which I've only seen for DC power supplies.

Here's a circuit for one: http://www.electronic-circuits.org/img/Bok3-24.jpg

Hey, I found one for AC!: http://www.circuit-projects.com/dimg/fast-electronic-fuse.gif

Needless to say, never construct or use such a circuit without reading the accompanying article.
 
LarryFine said:
I was gonna say the same thing. I've even seen articles in magazines such as Popular Electronics for building such circuits, which I've only seen for DC power supplies.

Here's a circuit for one: http://www.electronic-circuits.org/img/Bok3-24.jpg

Hey, I found one for AC!: http://www.circuit-projects.com/dimg/fast-electronic-fuse.gif

Needless to say, never construct or use such a circuit without reading the accompanying article.
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For safety reasons, I would not want a circuit to try to come back on after a short was detected, or even an over load.

Back a few years ago a few in the wall/window room air conditioners that had electric heat was designed manufactured and sold through the Fedders and Sears brand name with a automatic resetting thermo overload for the high temperature safety for the heating element shroud area, these caused a few fires when the blower motors failed, the hi temperature bug would just keep cycling and eventually the ABS plastic shroud would melt till it came in contact with the heating element and burst into flames. I did a discovery on one and sent all the info to UL, and pointed out about the improper use of the auto resetting hi limit. and an nation wide recall was sent out.

Safety devices should always be a manual type reseting device never automatic.
 
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Siemens sells a stand-alone unit for their power supplies called a Sitop Select (but they can be used with any 24VDC SMPS). It has 4 output circuits with "electronic fuses" that trip off line electronically: no moving parts. They can be auto or manual reset and you can get a trip signal. The trip points are adjustable up to 10A each. UL made them add actual "fuses" however, because UL has no classification for such a thing as an "electronic fuse", so each 10A circuit has a 15A fuse as the "backup" OCPD device to satisfy UL. The fuses never blow however, because the electronics trip earlier.

But there are limited to 24VDC; anyhting higher and the transistors become too expensive to be practical.
 
My '98 Ford has self-resetting overload circuits for important stuff like the headlights and windshield wipers. So they have been around for a while, any you don't have to have to spend a million to get high tech features like that.

I once had a headlight fuse blow one night while heading straight for a semi on a two lane road. I switched to the brights, and fortunately, they were on a different fuse. It would have been nicer if each light were on a separate fuse.
 
hurk27 said:
For safety reasons, I would not want a circuit to try to come back on after a short was detected, or even an over load.

Back a few years ago a few in the wall/window room air conditioners that had electric heat was designed manufactured and sold through the Fedders and Sears brand name with a automatic resetting thermo overload for the high temperature safety for the heating element shroud area, these caused a few fires when the blower motors failed, the hi temperature bug would just keep cycling and eventually the ABS plastic shroud would melt till it came in contact with the heating element and burst into flames. I did a discovery on one and sent all the info to UL, and pointed out about the improper use of the auto resetting hi limit. and an nation wide recall was sent out.

Safety devices should always be a manual type reseting device never automatic.
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It seems there could be a subtle difference in your example - between an overload/short circuit protection device and a thermal overload?

I agree 100% and I do not believe that any safety device should self-reset. Yet you see manufacturers get away with using self resetting thermal snap switches all the time.
In my design experience for the industrial environment we never allowed an over temperature circuit to self reset. Yet commercially they seem to get away with it.


I have ceramic top cooking unit in my kitchen that uses electronic (triac control) for the normal heating setpoint and thermal snap switches to protect against the elements over heating.

When I boil water on this unit with the electronic control knob set to 100%. The unit heats up and then eventually begins cycling on/off due to the thermal snap switches. (makes for a long boil time)
When I called to point this out to the company they said it was normal operation. I then followed up with a letter to the company explaining how I felt this was a safety issue.
They finally agreed to send a technicain out to look at it. He observed the behavior and said that was normal :roll:

I am not too concerned as there are no combustibles around the metal shrouded elements but I could not understand how they could get away with such a design. I am anxious to replace the unit with gas:grin:

Glad to hear you got such as positive response to your issue.
 
I cound't find the articel you mentioned, but sounds like polyfuses. We use them on circuitcards all the time. I don't *think* they make them in giant circuit panel size, at least the ones I've worked with are small 1A or less types. Does make it a lot easier to just reboot a PC when your memory stick shorts out the USB port than having to change out real fuses.

Saw that K-Egg car too. Yuck. Looks like a Ferrari spliced with some 90's GtT parts. Did someone try to rip off everyone elses supercar designs and end up with that harbor-freight knockoff?
 
Larryc39 said:
Saw that K-Egg car too. Yuck. Looks like a Ferrari spliced with some 90's GtT parts. Did someone try to rip off everyone elses supercar designs and end up with that harbor-freight knockoff?
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The automotive version of a platypus?
 
Well we have it micrologic breakers they have been around for many years Seimens General electric Square D .

And you program these meaning set points in the field per the engineer spec for trip setting .

They communicate with down stream breakers thur out the building with other panels and switchboards nothing new its old news .
 
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