Current source OK until load disconnected

[CDRIVE]

This could be use din parallel to the LED. If the voltage rises due to the removal of the LED or battery, the crowbar will short circuit the ring.

Only problem: how to turn off the crowbar after a new LED or battery has been inserted?

Harald

Too bad the current loop isn't pulsating DC. The SCR would reset itself, but then it wouldn't be a constant current loop. More like a max (peak) current loop.

If this is an emergency lighting system then a crowbar across the loop for other than over voltage from power supply failure would seem antithetical to an emergency lighting system. It would mean that if the user is removing - replacing a LED element he / she will be in the dark when the LED is removed. I would think that a system like this should have shunted sockets that close when the LED's removed and open when they're inserted. I'm not referring to a mechanical system either. I'm thinking of active sockets that know if a LED failed open too!

Chris

 

[(*steve*)]

Good point(s) Chris.

I'd add to that, that having a current source which destroys itself under no-load conditions is a very poor design that needs to be revisited.

I can only assume it's a switch mode device and that it turns the switching device hard on in these cases, although we have zero information about this. In fact the statement "Unicorns fart rainbows" tells us more about Unicorns than all we have been told about the current source.

 

[CDRIVE]

In fact the statement "Unicorns fart rainbows" tells us more about Unicorns than all we have been told about the current source.

Well you may not have learned anything here but I certainly have. This is useful information. I just have to find a practical use for it. How many Yuenglings' do you think it will take to come up with a stellar idea?

Chris

Edit: I'm willing to work hard at this!

 

[CocaCola]

How many Yuenglings' do you think it will take to come up with a stellar idea?

About this many or maybe it was that many, I can't recall all the variables right now... I do know it all depends on the number of them, or maybe the factor of the ratio of this to that? But, don't underestimate the vector of those enumerations when it comes to these factors and summary values in this equation... After all we also need to consider the effect of those specifications on that particular value as well as it's effect overall on the system... One must not forget that we derived these answers from the information that might have been lacking, or was it those numbers that was lacking?

In the end we want it to work like this not that, OK?

In closing we at least have some solid speculation on where rainbows come from, so it wasn't a total void of data...

 

[BobK]

About this many or maybe it was that many, I can't recall all the variables right now... I do know it all depends on the number of them, or maybe the factor of the ratio of this to that? But, don't underestimate the vector of those enumerations when it comes to these factors and summary values in this equation... After all we also need to consider the effect of those specifications on that particular value as well as it's effect overall on the system... One must not forget that we derived these answers from the information that might have been lacking, or was it those numbers that was lacking?

In the end we want it to work like this not that, OK?

In closing we at least have some solid speculation on where rainbows come from, so it wasn't a total void of data...

C.C., you have revealed an extraordinary new talent. You could be middle mangagement in any tech corporation in the U.S. of A. (approval by Dogbert notwithstanding).

bob

 

[CDRIVE]

sorry i can't reveal.

I'd never heard of this till 3 weeks ago myself.

Really? I didn't initially recognize your handle. If I had my first reply in this topic would have been another complaint about the same thing I complained about in your last topic. In your last topic I complained about your propensity for starting new topics that are nothing more than a continuation of your topic before it and before that one and before that one and before .... They date back far more than 3 weeks.

Personally, I think that misbehaving secret circuits should be disciplined by secret engineers under profitable contract with a non disclosure clause. This way all your secrets remain secret but at least the secret engineer will know what the hell he's dealing with!

I would highly recommend that others involved in this thread read back over eem2am other topics. You will discover that the current in this loop is NOT DC! It's 50kHz pulsating DC!! I think the AC prior to full wave rectification is 50kHz, so it's actually 100kHz pulsating DC. In that thread eem2am says it's sinusoidal but I don't believe that for a minute. This thing has the fingerprints of an unfiltered SMPS.

Chris

 

[eem2am]

thanks, yes its 100KHz haversine.....though thats a nice smooth waveform for us, and we're happy to put that through the LEDs

 

[CDRIVE]

thanks, yes its 100KHz haversine.....though thats a nice smooth waveform for us, and we're happy to put that through the LEDs

I like being here. So, what I'm thinking I can't post.

Chris

 

[BobK]

Let me guess, something like this project should have been on the 'Jersey shore a couple of weeks ago?

Bob

 

[eem2am]

I must admit, i find your disenchantmnt with this project very interesting.....do you know something that i don't about it?...or have you figured something out that i havent yet?

Seriously, i may only be doing the emergency light part of this project, but the overall project has come down from the very top height of world academia, and is revolutionary............at least thats what i am told.....

what are your misgivings?

when i came here, i wasnt told the origin of the project, but i sniffed around on the www, and seriously, the academic institution behind this project is up there with the best in the world

 

[CocaCola]

and is revolutionary............at least thats what i am told.....

LOL, with all that "revolutionary" talent at your disposal why are you here asking elementary questions? For example your new daily thread (on this same project after Steve has been warning you all week to stick to one thread) in regards to battery types, info that can be easily Googled up or should be obvious to such a talented "revolutionary" design team...

Also why would revolutionist even consider a design that is prone to self destruct? Seems totally illogical...

the academic institution behind this project is up there with the best in the world

Since it's their project and they are obviously "revolutionary" designers, again tell me why you are here when you have such a "revolutionary" team backing you?

 

[eem2am]

.....well to be honest, a question just came up about cell voltage equalisation circuitry in series cell battery packs.....so i am glad i did come here......to be honest, i am certain that most battery packs dont have internal individual cell voltage monitoring.......goodness knows why...since supercap stack chargers always monitor individual cap voltages, as a rule....and caps are basically cells.

 

[(*steve*)]

Damn. Did I leave 2 threads open. <shrug>

Check out the insides of a laptop battery, they're fully managed in this way.

Most largeish LiPo batteries have the taps available between cells to allow you to check this yourself.

Many LiPo cells have "protection" circuits to help save you from fire if you don't follow the rules.

If you have an unprotected battery, it is up to you to prevent fires.

Now... Can we continue this in the one thread I'm going to leave open?

https://www.electronicspoint.com/battery-comparison-emergency-light-t254488.htmlhttps://www.electronicspoint.com/current-source-ok-until-load-disconnected-t254330p4.html