2s smoke stopper

[ewokshoter]

setting up a 2s smoke stopper.

how should I wire these 6v bulbs I had?

https://www.amazon.com/Pack-Miniature-Screw-Light-Bulbs/dp/B01BRN3O6K/ref=sr_1_1?s=hi&ie=UTF8&qid=1522353603&sr=1-1&refinements=p_n_feature_keywords_three_browse-bin%3A7045648011

 

[kpixels]

setting up a 2s smoke stopper.

how should I wire these 6v bulbs I had?

https://www.amazon.com/Pack-Miniature-Screw-Light-Bulbs/dp/B01BRN3O6K/ref=sr_1_1?s=hi&ie=UTF8&qid=1522353603&sr=1-1&refinements=p_n_feature_keywords_three_browse-bin%3A7045648011

I think you want bulbs that are rated more than .5A. That's only 4 watts at 2s (~8V). PsyBorg will know, he probably hasn't seen this post yet. This thread might help;

http://forum.flitetest.com/showthread.php?38821-Psyborgs-Tips-n-Tricks-5-First-power-up-of-quad-power-train&highlight=smokestopper

 

[PsyBorg]

Already been mulling this over a bit. Ewok already hit me with the question in pm's a few days ago. I kinda got side tracked and forgot to finish researching how to do that with maybe the bulb in combination with possibly a power resistor like they used to use in the old brushed Tamaya monster trucks with the mechanical speed controllers.

 

[ElectriSean]

If you wire 2 of those lamps in series, you will be good for either 2s or 3s. You could probably get away with using only one for 2S assuming you don't run it in a short condition for long. Worst case it will simply burn out the lamp.

The current and power rating of the lamps is not really relevant, they are simply acting as a resistor to limit the current in the circuit. With 2 in series the max current in the circuit will be 0.25A if you have a short on the copter somewhere.

 

[ewokshoter]

so I built one with two bulbs in series and tried shorting it to test. all I got was sparks at the point of shortage.. any thoughts as to what this means?

 

[ElectriSean]

Can you post a picture?

 

[ewokshoter]

Can you post a picture?

The Photo wont seem to upload. basically i just soldered the positive wire between the two little bumps (hot contact points) on the very bottom of the bulb

 

[ewokshoter]

so you'll probably never let me live this down but I wired the bulbs wrong like a doofus. its working now but I have 2 problems

1. the bulbs take a moment or two to actually light up when shorted

2. i plan to power a fc stack with this and would prefer to not have to remove the fc. does anyone know if the bulbs will light up under normal conditions?

the stack is f3 mini magnum.

thanks!

 

[DamoRC]

so you'll probably never let me live this down but I wired the bulbs wrong like a doofus. its working now but I have 2 problems

1. the bulbs take a moment or two to actually light up when shorted

2. i plan to power a fc stack with this and would prefer to not have to remove the fc. does anyone know if the bulbs will light up under normal conditions?

the stack is f3 mini magnum.

thanks!

Depending on the voltage of the battery - it may take a moment for the filaments in the bulbs to come to temperature.

I am a little confused by the application here. I use something similar (3 bulbs in series) to fully discharge old batteries so I can safely tie the main and balance leads together prior to trashing the battery. But it sounds like you want to power an FC with this?

DamoRC

 

[ewokshoter]

Depending on the voltage of the battery - it may take a moment for the filaments in the bulbs to come to temperature.

I am a little confused by the application here. I use something similar (3 bulbs in series) to fully discharge old batteries so I can safely tie the main and balance leads together prior to trashing the battery. But it sounds like you want to power an FC with this?

DamoRC

Yes. its a smoke stopper. heres some info about them.
https://www.propwashed.com/protecting-electronics/

The problem is all info on them is for full size racers and powering with 3s lipos. my micro uses 2s and ive been trying to find a good solution for how to build a 2s smoke stopper. I plan to start a new thread somewhere with all the info compiled and credit for everyone whos helped here once im set on a design that works.

 

[DamoRC]

Thanks for the link - very helpful, and now I understand what you are trying to do.

DamoRC

 

[Craftydan]

The 12v blubs are a resistive load that is conveniently sized so an idle ESC will have enough voltage to run, but an throttle-up ESC will brown out. Something goes wrong or you throttle-up, the bulb is now dropping too much voltage from the ESC's current demand.

While it might not light up (or light as brightly), it doesn't matter if the input voltage is 12v or 8v. If the idle ESC isn't demanding much current, the bulb won't starve the ESC of voltage, and when the ESC demands too much, the bulb will throttle the voltage back. So long as a 12v bulb in series with the ESC can still boot-up on a 2S pack, you're good to go.

A 12v bulb also has the distinct advantage of being roughly twice the resistance of 6v bulb sized for the same current load. Any short or mis-wiring or stupid ESC ROMs will only brown-out faster at a lower voltage.

 

[ewokshoter]

The 12v blubs are a resistive load that is conveniently sized so an idle ESC will have enough voltage to run, but an throttle-up ESC will brown out. Something goes wrong or you throttle-up, the bulb is now dropping too much voltage from the ESC's current demand.

While it might not light up (or light as brightly), it doesn't matter if the input voltage is 12v or 8v. If the idle ESC isn't demanding much current, the bulb won't starve the ESC of voltage, and when the ESC demands too much, the bulb will throttle the voltage back. So long as a 12v bulb in series with the ESC can still boot-up on a 2S pack, you're good to go.

A 12v bulb also has the distinct advantage of being roughly twice the resistance of 6v bulb sized for the same current load. Any short or mis-wiring or stupid ESC ROMs will only brown-out faster at a lower voltage.

Im a little bit lost..
what is an ESC ROM googles only showing me the "European society of cardiology" lol

are you saying that 12 or 6v bulb doesnt matter? I was thinking that for a more powerful bulb the current it takes to fry my board is less than that which is required to light the bulb.

I think this because ive fried THREE (can you sense my frustration?) f3 femtos with a smoke stopper plugged in.

 

[Ray K]

I'll admit I know nothing about quads, but I have to ask, can anybody say "Fuse"?

 

[ewokshoter]

I'll admit I know nothing about quads, but I have to ask, can anybody say "Fuse"?

Hmmm?

 

[Ray K]

Hmmm?

Yeah, you know, it's that little critter that blows open when too much current tries to pass through. Kinda old school stuff. But I probably don't understand your need well enough.

 

[ewokshoter]

Yeah, you know, it's that little critter that blows open when too much current tries to pass through. Kinda old school stuff. But I probably don't understand your need well enough.

I should be clear that I know what a fuse is but the point of this is to eat up the resulting current spike if there is a short AND give you the visual cue (light bulb) that something is wrong.

 

[Ray K]

I should be clear that I know what a fuse is but the point of this is to eat up the resulting current spike if there is a short AND give you the visual cue (light bulb) that something is wrong.

The fuses I grew up with are slowly but surely disappearing, so it wouldn't surprise me if younger folks didn't really know much about them. You need to know, I meant no disrespect to anyone. I do hold an MSEE and a slo-blo fuse sounded like an answer to what you need. Again, however, I know little about quads beyond their having 4 props (some of them, anyway), and I can't fly them worth a plugged nickel.

 

[ewokshoter]

No need to worry. No hard feelings over a little miscomunication.

 

[makattack]

I know the bulb/fuse based current limiting devices are great and inexpensive, but if you wanted more flexibility, I am loving how useful my DIY current/voltage limited supply is working out for me:

http://forum.flitetest.com/showthre...Bench-Power-Supply&highlight=power+supply+diy

It's programmable, so the interface can be pretty much optimized for RC stuff. I've programmed 1S, 2S, 3S, 4S setups. It'll definitely cost more. I probably could have saved money and time by buying a used bench power supply, but I liked the idea of building this and having a more DIY version... with the caveat that this is most certainly not UL certified!