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Re: Seeking low current breakers.

Current range 0.1 Amp - 1 Amp, max voltage 120V.

> A site would be fine. > > How much would I expect to pay? > > I will be beholden to you in the after-life for your > divine guidance. > Ken

At the low end of your current range are things like the Phoenix Contact 0915475.

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htm $50-$60 range.

At the high end of your current range there are cheaper little push to reset breakers. e.g.

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$5 range.

In many fields today this sort of current range is often handled by overcurrent detection and shutdown in the supply, or a "Positive Temperature Coefficient Resettable Fuse",called (in the same tradition as Kleenexes or Xeroxes) "Polyswitches". Far cheaper than the old magneto or thermal breakers.

Polyswitches have different failure modes and mechanisms than the old magneto/thermal breakers. It's possible that your choice is constrained by the equivalent of an national or industry electrical code.

Tim.

Reply to
Tim Shoppa
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"Ken S. Tucker" kirjoitti viestissä: snipped-for-privacy@l17g2000yqe.googlegroups.com...

Some standard DIN-rail-mountable are available in that current range For example ABB S200 series breakers (S281 UC-K) are available down to 0.2 A Their internal resistance is quite high for 12 V operation tought.

Datasheet (if that link works):

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$file/2cdc%20400%20021%20d0201.pdf

-ek

Reply to
E

84.htm

entDelivery/DDECon...

A typical AC operated power supply has the breaker on the input side of the supply. Often in a 12VDC application the voltage drop across a Polyswitch or magnetic/thermal actuated breaker is regarded as onerous.

(This isn't necessarily true, there are supplies that additionally have breakers on DC outputs depending on what failure modes are being anticipated. Usually breakers and fuses are there to protect against wiring fires, not to protect the load from an overcurrent but there are applications where the load has its own breaker to protect from, say, motor winding overtemps etc. Motor winding breakers have their own special characteristics and classifications.)

I am unclear on why a 12V lamp circuit would use a circuit breaker. Look at e.g. the 12V fuses used in cars to protect against wiring fires.

Tim.

Reply to
Tim Shoppa

They were common in the tube type TV days. Sold by Belfuse, Workman Electronics and other manufacturers.

--
For the last time:  I am not a mad scientist, I'm just a very ticked off
scientist!!!
Reply to
Michael A. Terrell

Well, Mouser has some small breakers pretty cheap, but 0.1 amp seems to be going to set you back $63/each. 0.2 is nearly as bad. At a quarter-amp (0.25) you start getting into reasonable prices ($5.40 each) and can stay there or below up to an amp (down to $4.50 in 100's - if you are buying thousands you should shop around some and can likely do better)

If you get fancy and want things like DIN rail mounting, the price about triples.

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Cats, coffee, chocolate...vices to live by
Reply to
Ecnerwal

2A would be easy enough to find; have you considered just using a sense resistor, and firing off a triac to trip a larger breaker? Or, using a NO relay, and interrupting it on measuring an overcurrent event?

I'm presuming this doesn't have to be the only fire protection for a building (you can"t build your own if it needs regulatory approvals).

Reply to
whit3rd

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