Author Topic: How to use the same RELAY on 12V & 24V vehicles  (Read 12123 times)

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Offline JDWTopic starter

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #50 on: August 18, 2019, 09:20:53 pm »
Your question was answered already wasn't it? It's not unusual at all for threads to wander into other topics once the question has been answered.

 :palm:

Might as well talk religion, politics and space exploration too. Apparently, anything goes in this forum!
 

Offline Richard Crowley

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #51 on: August 19, 2019, 02:04:28 am »
Might as well talk religion, politics and space exploration too. Apparently, anything goes in this forum!
Quite to the contrary.  The "topic-drift" is one of the better features of this forum. We read (and participated in) several possible solution to your problem, but also discussion of several related issues.   :-+
 
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Offline JDWTopic starter

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #52 on: August 19, 2019, 02:46:07 am »
From "About Us": "The site is essentially a self moderated forum, and people lead by example."

And the example appears to be, "ramble on, folks!"

Who am I to stop to the party?  Carry on!
 

Offline james_s

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #53 on: August 19, 2019, 04:35:13 am »
Well you're welcome to duck out at any time should the topic of discussion no longer be relevant to you. Nobody is forcing you to stick around and listen to our chatter. You're as welcome as anyone to hang out here but you don't get to dictate what people talk about. Topic drift is par for the course, if you're bothered by that then this probably isn't the forum for you.
 

Offline JDWTopic starter

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #54 on: August 19, 2019, 04:45:02 am »
Sorry, but there's where I draw the line.  "Nobody is forcing you to hear the chatter" is a ridiculous statement because I created this thread and therefore it's obvious I will follow it to see if someone ever posts a relevant-to-the-title reply that may interest me.

Why not just start your own thread(s) and leave this one alone so that people who come to this threat with the understanding it will be on-topic can follow this thread more easily to its final conclusion?

This is becoming an example of why most forums cannot moderate themselves because many people posting to the forums think they are always right going about it the way they feel is best.  But I assure you, when there is conflict brewing, it's time to create your own thread.  So please do that.  Now.

Thank you.
 

Offline james_s

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #55 on: August 19, 2019, 04:55:40 am »
No, sorry, you don't get to make demands like that.

One of the things you will learn real quick around here (and I'm quite sure Dave will back me up on this if he happens to see it) is that you own your posts and your posts only. You do not own the thread, you do not get to tell others what to discuss, you do not get to tell others not to post. If you don't like where a thread goes that's tough, you can politely request people stick to the topic at hand, or you can leave, or add certain members or certain threads to your ignore list. Start trying to throw your weight around and make demands and you'll not make many friends around here, that's not how it works.
 
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Offline JDWTopic starter

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #56 on: August 19, 2019, 05:08:41 am »
Start trying to throw your weight around and make demands and you'll not make many friends around here, that's not how it works.
I respect your sentiments, but please consider reasonably who is throwing whose weight around.  Do you consider the wording of your own previous post "friendly"?

Logic itself dictates that rambling on and on within someone else's post is showing oneself rather unfriendly.  The evidence that is true exists in pretty much every other forum out there -- hijacking threads is almost always prohibited to prevent conflicts like this.  And while I am aware no such prohibition exists here, and while I for the most part don't mind that free-for-all way of thinking, it is greatly appreciated when others would be friendly enough to so kindly consider the heartfelt wishes of the individual who started the thread.  It's merely a common courtesy.  That is what I have been pleading with you gentlemen about for the last several posts. But until now, my thoughts have been trampled under foot and I am considered to be someone who can no longer make friends here.  That's quite a punch below the belt.

Friends, if I am totally in the wrong in thinking the way I do about this particular thread, I humbly ask for everyone who has posted in this thread thus far to share your opinion telling me so.  I am happy to abide by the group feeling on this matter.  For now, I still feel the current dialog is cluttering up the thread and makes it more difficult for other people in the future to find useful information in this thread.  As such, it would be greatly appreciated if those who wish to continue the current off-topic discuss could please open a new thread.  And I promise I will not post in your thread to mucky it up.  This is how friends behave toward one another.  I hope I can obtain your kind understanding about this.

Thank you for your kind cooperation and understanding.
 

Offline floobydust

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #57 on: August 19, 2019, 06:15:26 am »
I go off-topic if I know (with facts) a technical example or statement is misleading, such as linear constant-current control not contributing to global warming, or is used for motor speed control... Usually that doesn't derail a thread, but it does seem to take the piss on a decent discussion if people react and get cranky and defensive, unleash a wall of text or start up the flame thrower. I see it happen frequently- not just here, but on many Internet forums. Mixing noobs, professionals, enthusiasts, old farts, and jerks along with different language and culture - there will be clashes and it's bound to be noisy.

In social media, using up/down votes was supposed to improve the signal/noise ratio in threads, but bots and brigading etc. corrupted that idea. It's possible to manipulate votes.
Nothing better has been found. It all seems to rely on the manners of the community, or the hostile members get banned by the mods.

I think best is to ignore the few posts that wandered off-topic and adding new (relevant) posts to a thread seem to keep it going.
 

Offline bloguetronica

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Re: A thread that has gone off-topic
« Reply #58 on: August 19, 2019, 10:37:49 am »
The lack of sympathy and trolling from some members, plus 50% of topics going off... topic. That indeed characterizes these forums, but it is certainly not a feature.

The eevblog forums are on the extreme of the bell curve of forums, as atypical they are (perhaps head-to-head with reddit). Now talking about bells, I have an urge of hearing Anita Ward.

Kind regards, Samuel Lourenço
 

Offline ogden

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Re: A thread that has gone off-topic
« Reply #59 on: August 19, 2019, 11:09:49 am »
Changing subject of thread to meaningless whine is much worse "off-topic" than posting irrelevant to original question, post. Completely agree that OP does not "own" the thread. As soon as thread is going and people invested their time answering question or just sharing their opinions, it becomes **common** knowledge of community of this forum.

[edit] Show respect to those who did stick to original subject and be so kind - change subject back to original.
« Last Edit: August 19, 2019, 11:17:39 am by ogden »
 

Offline Zero999

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #60 on: August 19, 2019, 11:25:41 am »
All threads drift off topic, but as long as it's vaguely technical, I don't see the problem. In this case someone posted a circuit originally designed for something else, but might suit the original poster's application. Inevitably the topic wandered off to the subject of that circuit. If you feel as though your question has not been answered, simply provide more information, rather than complaining about it.

Anyway, back on topic. The circuit Soldar posted can be modified into a crude switched mode power supply by adding a couple of RC circuits. It will self-oscillate at around 1kHz, when the current exceeds a certain threshold, determined by R1, which will give about 60mA, in this case. The inductance of the relay will smooth the current so it doesn't chatter. At low supply voltages, Q1 will simply be solidly on, with no oscillation. The efficiency won't be great, but it's better than a linear current limiter.

The circuit can be driven from a 5V microcontroller output if R2 is reduced to 2k2 and its positive node is connected to the output, rather than 24V.
 

Offline ogden

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Re: A thread that has gone off-topic
« Reply #61 on: August 19, 2019, 11:29:59 am »
TLDR; - Did anybody suggest to use switching supply to create 5V rail for 5V relay and LDO for 3.3V rail?

Now I technically posted off-topic because thread is about "Re: A thread that has gone off-topic". Whatta...
 

Offline Zero999

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #62 on: August 19, 2019, 11:33:14 am »
TLDR; - Did anybody suggest to use switching supply to create 5V rail for 5V relay and LDO for 3.3V rail?

Now I technically posted off-topic because thread is about "Re: A thread that has gone off-topic". Whatta...
I'm not sure if those exact solutions have been proposed, but I think a switched mode power supply has been mentioned before.

EDIT:
[edit] Show respect to those who did stick to original subject and be so kind - change subject back to original.
I did and you changed it back. This reply was solely to change the topic back to the original again. Please don't change it back again.
« Last Edit: August 19, 2019, 11:36:53 am by Zero999 »
 

Offline bloguetronica

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Re: A thread that has gone off-topic
« Reply #63 on: August 19, 2019, 11:40:49 am »
Changing subject of thread to meaningless whine is much worse "off-topic" than posting irrelevant to original question, post. Completely agree that OP does not "own" the thread. As soon as thread is going and people invested their time answering question or just sharing their opinions, it becomes **common** knowledge of community of this forum.
Neither you apparently. Do you want to know who owns the thread?  Whoever owns the forum (Dave). Anyway, drifting off-topic is disrespecting the OP.

Kind regards, Samuel Lourenço
 

Offline ogden

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #64 on: August 19, 2019, 11:43:52 am »
[edit] Show respect to those who did stick to original subject and be so kind - change subject back to original.
I did and you changed it back. This reply was solely to change the topic back to the original again. Please don't change it back again.

LOL. You did not change subject of the *thread*, just your post. Also - I did not answer to your post.
 

Offline ogden

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Re: A thread that has gone off-topic
« Reply #65 on: August 19, 2019, 11:46:45 am »
Changing subject of thread to meaningless whine is much worse "off-topic" than posting irrelevant to original question, post. Completely agree that OP does not "own" the thread. As soon as thread is going and people invested their time answering question or just sharing their opinions, it becomes **common** knowledge of community of this forum.
Neither you apparently. Do you want to know who owns the thread?  Whoever owns the forum (Dave).

Dave does not own thread same way as Google/Alphabet does not own e-mails sent by me with gmail.

Quote
Anyway, drifting off-topic is disrespecting the OP.

Your current post is off-topic according your logic as well, yet you openly chose to disrespect OP. How's that?
« Last Edit: August 19, 2019, 12:04:41 pm by ogden »
 

Offline bloguetronica

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Re: A thread that has gone off-topic
« Reply #66 on: August 19, 2019, 11:55:32 am »
Anyway, I don't want to feed disruptive behavior, and I'm purposefully ignoring some previous posts. I think the OP should change the title back.

Kind regards, Samuel Lourenço
 

Offline EEVblog

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #67 on: August 19, 2019, 11:55:44 am »
Changing the thread topic to something completely different is silly and doesn't help anyone, please don't do that. I changed it back.

I have not followed this thread, but it's quite  common for threads to drift off-topic a bit or into other areas of a related problem when the question has been answered.
If anyone wants to bring a thread back "on topic" then you do that by posting on-topic stuff again, then people will respond to you, etc.
« Last Edit: August 19, 2019, 11:58:04 am by EEVblog »
 
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Offline EEVblog

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Re: A thread that has gone off-topic
« Reply #68 on: August 19, 2019, 12:02:04 pm »
The lack of sympathy and trolling from some members, plus 50% of topics going off... topic. That indeed characterizes these forums, but it is certainly not a feature.
The eevblog forums are on the extreme of the bell curve of forums, as atypical they are (perhaps head-to-head with reddit). Now talking about bells, I have an urge of hearing Anita Ward.

You are not helping the situation with your posts.
 

Offline bloguetronica

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #69 on: August 19, 2019, 12:08:25 pm »
Now, my answer. The quick and simple solution, provided your relay requires a very low current ( below 20mA) is to just use a 12.6V Zener diode in series. Above that current, you could use an LDO. There are also 24V to 12V DC-DC modules that are transparent enough to allow 12V operation without any drop.

Anyway, whatever solution you use, your relay will require a freewhelling diode so it doesn't damage whatever is controlling it.

Kind regards, Samuel Lourenço
« Last Edit: August 19, 2019, 12:10:12 pm by bloguetronica »
 

Offline EEVblog

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #70 on: August 19, 2019, 12:10:24 pm »
Sorry, but there's where I draw the line.  "Nobody is forcing you to hear the chatter" is a ridiculous statement because I created this thread and therefore it's obvious I will follow it to see if someone ever posts a relevant-to-the-title reply that may interest me.
Why not just start your own thread(s) and leave this one alone so that people who come to this threat with the understanding it will be on-topic can follow this thread more easily to its final conclusion?
This is becoming an example of why most forums cannot moderate themselves because many people posting to the forums think they are always right going about it the way they feel is best. But I assure you, when there is conflict brewing, it's time to create your own thread.  So please do that.  Now.
Thank you.

And you are also doing that now by insisting that threads stay completely on-topic with zero side-banter and technical tangents.
This forum has grown into being one of the biggest and best engineering forums on the internet partly because it doesn't insist on strict moderation like that.
I've seen technical forums die because everyone tries to play forum-cop and moderate the forum into oblivion, I won't let that happen here.
People can "moderate" threads by politely asking if people could keep it on topic, or better yet, simply post on-topic stuff themselves and lead by example.
 

Offline EEVblog

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #71 on: August 19, 2019, 12:13:28 pm »
Might as well talk religion, politics and space exploration too. Apparently, anything goes in this forum!

FYI, religion and politics are essentially banned here. Start talking that and threads get locked. Do it consistently and you'll get banned.
Space exploration talk is technically interesting and is basically an engineering related problem, so it's good.
 

Offline mariush

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #72 on: August 19, 2019, 12:17:27 pm »
A 12v battery could be below 12v but 12v relays would work still.
did anyone mention bi-stable relays?
You could then use a ldo for the 2-3s pulse needed to switch the relay...but then you'd have to hold some charge so when power is off you can reset the relay to other position, if that's important.
 

Offline ogden

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #73 on: August 19, 2019, 12:26:36 pm »
Now, my answer. The quick and simple solution, provided your relay requires a very low current ( below 20mA) is to just use a 12.6V Zener diode in series.

Are you sure such solution will work not only on 24V supply but on 12V as well? How? Please explain.
 

Offline Zero999

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Re: How to use the same RELAY on 12V & 24V vehicles
« Reply #74 on: August 19, 2019, 12:48:06 pm »
Now, my answer. The quick and simple solution, provided your relay requires a very low current ( below 20mA) is to just use a 12.6V Zener diode in series.

Are you sure such solution will work not only on 24V supply but on 12V as well? How? Please explain.
It won't work. All a zener will do is reduce the supply voltage by 12.6V.


[edit] Show respect to those who did stick to original subject and be so kind - change subject back to original.
I did and you changed it back. This reply was solely to change the topic back to the original again. Please don't change it back again.

LOL. You did not change subject of the *thread*, just your post. Also - I did not answer to your post.
That's strange. When I changed the title of my post, the name of the thread also changed, but then it reverted back, when you posted. I apologise for accusing you of doing it intentionally.

Anyway, here's another idea, based along the same lines. The switching is harder and faster so it should be lower loss and it has better current regulation, as the sense resistor is directly in series with the relay, but requires more parts.
« Last Edit: August 19, 2019, 12:49:55 pm by Zero999 »
 


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