Is there a device that stops a small current passing but allows a large current?

Tonyr1084

Joined Sep 24, 2015
9,744
In regards the silence of this lamb (the OP), there have been times I've posted a question and then was not able to get back to it for a day or two. Maybe there's a reason the OP hasn't gotten back with us.

As far as admitting ones lack of knowledge, I've experienced this: Sometimes a person has no idea what the answer may be. Yet they open their mouths and speak as an expert, TRYING to look intelligent. IMO, it's smarter to acknowledge your lack of knowledge than to try and give an answer that is entirely full of poop. People who answer without knowing what they speak of only show themselves to be highly unintelligent. I'd rather say "I don't know" and let people respect me for that honesty than to try and answer and look like a fool.

There's a saying I heard somewhere before: "It's better to let people think you're a fool than to open your mouth and remove all doubt." Maybe I should post that as my message. I've seen others with things like "Necessity is the mother of invention" and haven't figured out how to put such a posting on my page. Any help with that?

I REALLY like MrChips quote on binary. Took me a couple seconds to catch on.
 
...and haven't figured out how to put such a posting on my page. Any help with that?
Yes, Indeed!:)

You may access the signature editor as follows:

For 'Blue Style':

1) Hover over your username tab (top of page, third item from the right)
2) Select 'signature' from the resulting drop-down menu (2'nd item, left column)

For 'Orange Style':

Hover over your avatar image (upper right corner of page)
Select 'Your Account' (top item in resulting drop-down menu)
Scroll down to and select 'signature' under settings..

Best regards
HP:)
 
Last edited:

OBW0549

Joined Mar 2, 2015
3,565
Sometimes a person has no idea what the answer may be. Yet they open their mouths and speak as an expert, TRYING to look intelligent. IMO, it's smarter to acknowledge your lack of knowledge than to try and give an answer that is entirely full of poop. People who answer without knowing what they speak of only show themselves to be highly unintelligent.
I call this "meta-ignorance." A person who's meta-ignorant is one who is so ignorant he's blissfully unaware of his own ignorance-- that is, he doesn't know what he doesn't know. All discussion boards, including this one, have a few of these (though none have showed up in this thread), and the main problem with them is they tend to give out bad advice which newbies might not be able to recognize as bad. They also waste time and effort when other people have to step in and correct their misstatements.

A smart person will maintain a clear and conscious awareness of the limits of his own knowledge, and will keep his mouth shut when he knows he's not competent to answer a question.
 

Thread Starter

Bhope691

Joined Oct 24, 2016
38
Thanks for the responses from all.

Tonyr1084 thanks for trying a solution.

MaxHeadroom, MrChips and DickCappels thanks for the suggestions I believe a DIAC comes closest to what I am looking for at the moment, but it doesn't seem to be exactly what I am after, however, the flux capacitor sounds interesting and may have the answer.

The question was made in haste to gauge if something was available. It turns out trying to explain fully what I am after is much more complex than I thought. Once I have been able to get something on paper I will add it to the thread and see if it gives a bit more clarity for those who are still interested.
 
@Bhope691 --- Many sincere thanks for following up your OP!:)

the flux capacitor sounds interesting and may have the answer.
--Emphasis Added--
Without wishing to play the 'killjoy', I trust you realize said item is a fictional device?:rolleyes:

The question was made in haste to gauge if something was available...
Speaking for myself (and, I daresay, a few others;)) -- I'd far prefer to assist you with your question than attempt to 'divine' same...:rolleyes::cool:

It turns out trying to explain fully what I am after is much more complex than I thought. Once I have been able to get something on paper I will add it to the thread and see if it gives a bit more clarity...
Tell ya what... Please! Merely ask your question and skip the rigmarole....K?:rolleyes:

I believe a DIAC comes closest to what I am looking for at the moment
Please be advised that DIACs, being, as they are, principally 'small signal' devices, are not commonly available for power handling applications -- You may, of course, implement said function via power handling thyristors (e.g. certain SIDACs, TRIACs or, where unipolar operation is acceptable, SCRs) -- Note that, owing to the limited (rather high) range in commonly available Vbo, TRIACs and SCRs are most practically triggered via their gate connection (as, for instance, by an appropriately specified DIAC)...

Best regards
HP:)
 
Last edited:

uradhura

Joined Jan 18, 2017
6
Not a simple component, but a circuit. You would need to get specific about how much current you were talking about.
Second concern ... :) if you have to ask the question could you understand the answer?
If we gave you as circuit design could you build it? No insult intended, I don't know your abilities, this being your first post.
Yes, the problems mentioned are a killer. Let's hear the original condition that is trying to be dealt with. If you turn off the circuit at a small current you can't develop a high current.
It looks like making hot ice, is it voltage or current?
 
Last edited:

GopherT

Joined Nov 23, 2012
8,009
...
As far as admitting ones lack of knowledge, I've experienced this: Sometimes a person has no idea what the answer may be. Yet they open their mouths and speak as an expert, TRYING to look intelligent. IMO, it's smarter to acknowledge your lack of knowledge than to try and give an answer that is entirely full of poop. People who answer without knowing what they speak of only show themselves to be highly unintelligent. I'd rather say "I don't know" and let people respect me for that honesty than to try and answer and look like a fool.

There's a saying I heard somewhere before: "It's better to let people think you're a fool than to open your mouth and remove all doubt." Maybe I should post that as my message. I've seen others with things like "Necessity is the mother of invention" and haven't figured out how to put such a posting on my page. Any help with that?

I REALLY like MrChips quote on binary. Took me a couple seconds to catch on.
Careful, you are close to discussing politics/politicians in an on-topic thread.
 

Aleph(0)

Joined Mar 14, 2015
597
Careful, you are close to discussing politics/politicians in an on-topic thread.
GopherT you're right abt that but problem is in politics ignorance is in eye of beholder that's why I chose science:)! Only thing is science isn't immune from being co-opted by politics cuz where there's a stake it always leans toward highest bidder:( And it can take more than a lifetime for truth to come out! I say anyone thinking truth is consensus based is politician NOT a scientist! So for historical example think on Joseph Priestly and phlogiston theory! Like HP says It's crazy ironic when you know Priestly was discover of O2 which was key to understanding TRUE nature of combustiono_O:cool:
 

GopherT

Joined Nov 23, 2012
8,009
GopherT you're right abt that but problem is in politics ignorance is in eye of beholder that's why I chose science:)! Only thing is science isn't immune from being co-opted by politics cuz where there's a stake it always leans toward highest bidder:( And it can take more than a lifetime for truth to come out! I say anyone thinking truth is consensus based is politician NOT a scientist! So for historical example think on Joseph Priestly and phlogiston theory! Like HP says It's crazy ironic when you know Priestly was discover of O2 which was key to understanding TRUE nature of combustiono_O:cool:
Differing frames of reference and differing life experiences can cause trend lines to be drawn quite differently for the same limited data (and even deciding whether or not enough data exists to draw a trend line). This is why science is published and debated.

The trouble with science comes when debate is not allowed or data is not published and minds not open.
 

Aleph(0)

Joined Mar 14, 2015
597
Differing frames of reference and differing life experiences can cause trend lines to be drawn quite differently for the same limited data (and even deciding whether or not enough data exists to draw a trend line). This is why science is published and debated.

The trouble with science comes when debate is not allowed or data is not published.
Gophert I agree and it's sad cuz that's how science starts being politics:( I say a good scientist needs imagination but has to be free of expectations and biases but that's problem cuz dispassionate ppl usually lack imagination too:rolleyes: I really think collaborative science is becoming a worse and worse failure cuz it's human nature that _team play_ has never been a friend of truth:(! So _collaborative_ no! But cooperative is imperative! So the lower the perceived stakes the better the science:cool:!
 

Tonyr1084

Joined Sep 24, 2015
9,744
GopherT, thanks for being the first to mention politics. I know I certainly didn't. Nor was I even thinking anything remotely having to do with that aspect of life. I was referring to those HERE who give advice when they themselves have no idea of how to properly solve a problem with a project. Politics and politicians never entered my mind. So please don't lay the blame at my feet, you were the first to mention the "P" word.
 

GopherT

Joined Nov 23, 2012
8,009
GopherT, thanks for being the first to mention politics. I know I certainly didn't. Nor was I even thinking anything remotely having to do with that aspect of life. I was referring to those HERE who give advice when they themselves have no idea of how to properly solve a problem with a project. Politics and politicians never entered my mind. So please don't lay the blame at my feet, you were the first to mention the "P" word.
You should get a medical checkup. Ask your doctor to give you a full-body X-Ray. Tell him you may be missing your Funny Bone!
 

NPN-1

Joined Mar 11, 2016
16
I suppose what the OP is asking is a device, in parallel or shunt to the rest of the circuit, that allows a low current to go through. However when a higher current passes through the same circuit (due to an overload, shortcircuit etc.), then the parallel sub-circuit switches on and takes the excess current itself so that the remaining circuit is not damaged. Sort of an excess current protection circuit.
 

djsfantasi

Joined Apr 11, 2010
9,237
I suppose what the OP is asking is a device, in parallel or shunt to the rest of the circuit, that allows a low current to go through. However when a higher current passes through the same circuit (due to an overload, shortcircuit etc.), then the parallel sub-circuit switches on and takes the excess current itself so that the remaining circuit is not damaged. Sort of an excess current protection circuit.
From his title, I thought he was looking for the opposite effect.
 
Top