Phil Posted January 16, 2021 Posted January 16, 2021 I built a 1 cue remote firing circuit a while back with one of those generic 12v RF relays you find all over ebay and while it worked wonderfully with the 12v wall adapter I was using to power it, switching it over to battery power doesn't seem to be going so smooth. I had my homemade wirewound igniters dialed in for that power supply, they would glow almost white hot after a half second or so of holding the button. I had 4 rechargable NIMH AA batteries laying around and decided to utilize those. Measuring from the holder I get 5.1V which is within input range for the converter I have. I have the output adjusted to 12V and it seems to power everything fine up until the moment I go to power an igniter. I feel like it's shorting. The relay opens and closes very rapidly, it sounds like buzzing (like if I was to bridge the output speaker terminal with a paperclip). Before switching over to batteries I measured the current pull with my igniters at 1.5AMPS. Where am I going wrong?
Carbon796 Posted January 17, 2021 Posted January 17, 2021 Sounds like the boost converters output probably needs to be rectified and or filtered. Your probably energizing the DC relays coil, at the converters operating frequency.
Phil Posted January 17, 2021 Author Posted January 17, 2021 (edited) How would I go about that? I have some caps and diodes. I assume cleaning up the output would involve those.I tried placing a cap (I have 330uf, 470uf and 1000uf) after the converter's output and it slowed the frequency of the relay module opening and closing enough to where it no longer sounds like buzzing however it's not staying closed even remotely long enough to heat up the igniter. The linked video demonstrates the result as I hold the button down.https://streamable.com/739h2f Edited January 17, 2021 by Phil
Arthur Posted January 17, 2021 Posted January 17, 2021 The change that you made that stopped it working was to change the power supply, look again at that. what do you have? Could you use a 12v sealed lead acid battery from an alarm or from a lawn tractor(etc). could you use 12v in the form of a tool battery (drill etc) could you use 12v from a series pack of AA batteries, or a 12v lantern battery.
Phil Posted January 17, 2021 Author Posted January 17, 2021 (edited) I wasn't using the converter before either. I suppose I COULD change the source, however the idea was that whatever I ended up using was compact enough to fit in this box. If I absolutely can't get what I need with what I have from 4 AAs I could order some other type of pack or construct my own, the question is what do I use? You mentioned tool batteries, is it possible to use 18650 batteries or something of the like to get 12v and what would I need? Would something like this work as a cheaper option? https://www.ebay.com/itm/12V-1300mAh-NI-MH-Rechargeable-Battery-Pack-Ultracell-Tamiya-Plug-US-Free-Ship/363075958099 Edited January 17, 2021 by Phil
Richtee Posted January 17, 2021 Posted January 17, 2021 (edited) Just get a 12V 7-8 AH gel cell. An alarm battery. Plenty of balls for what you need. And a 12V trickle charger. Prolly all together $40. Edited January 17, 2021 by Richtee
SeaMonkey Posted January 19, 2021 Posted January 19, 2021 Four AA size NiMH cells series connected to provide a nominal 5.2 Volts to theBoost Converter for a 12 Volt Output will not be effective. The AA size NiMH cells cannot provide sufficient current to sustain a hefty 12 Voltoutput for more than a few seconds. NiMH cells aren't designed for heavy currentoutput as the NiCd cells of earlier times were. A 12 Volt Sealed Lead-Acid battery would do the trick as Richtee suggested. Or, four Lithium Cells series connected to provide about 14 Volts would also dowell and would fit within your plastic box. Boost Converters need a battery source that is capable of supplying heavycurrent in an application such as you have. 5 to 6 Volts at the Input to theConverter with the capability to supply about 10 Amperes for several minuteswould be enough reserve energy to provide the Amperage at 12 Volts in orderto ignite your electrical ignitors quickly.
Arthur Posted January 19, 2021 Posted January 19, 2021 The trouble with boost converters is that they get the volts from the supply at the cost of increased current draw. Likely a really big 6v supply would work through the converter as would a 12v 0.8Ah SLA or bigger.
Richtee Posted January 19, 2021 Posted January 19, 2021 (edited) I still think he’s trying to computerize a toilet Get a damn gel cell and be done with it. https://www.homedepot.com/p/MIGHTY-MAX-BATTERY-12-Volt-7-Ah-Sealed-Lead-Acid-SLA-Rechargeable-Battery-ML7-12/307979135?source=shoppingads&locale=en-US https://www.homedepot.com/p/Smartech-Products-Smartech-0-75-Amp-6-Volt-12-Volt-Trickle-Battery-Charger-Maintainer-IC-750/309462998?source=shoppingads&locale=en-US There’s an engineering principle I learned early on... called the “KISS” principle. I bet some of ya heard of it Edited January 19, 2021 by Richtee
Phil Posted January 20, 2021 Author Posted January 20, 2021 I think I'll try richtee's suggestion and grab one of those 12v lead acid batteries. Wouldn't be in the box like I wanted but it's progress and better than running an extension cord. I'll figure out the downsizing part later when I get everything together with something a bit more permanent than a breadboard. Hasn't totally been time wasted because now I got a few extra gadgets sitting around that I now know aren't exactly as straightforward as I expected. Guess I know one more way not to do it.Thanks guys.
Richtee Posted January 21, 2021 Posted January 21, 2021 Guess I know one more way not to do it.Thanks guys.Thomas Edison..I think it was said “I have not failed. I have found 10,000 ways that do not work" Carry on soldier.
Arthur Posted January 21, 2021 Posted January 21, 2021 A quick search on Mouser's www shows SLA batteries from 200mAH, I'm sure you could find something to fit your box and fit the function. The Chinese, Kingdom 20 chan remote controller works fine and contains a 800mAH 12v sealed lead battery.
Richtee Posted January 21, 2021 Posted January 21, 2021 Yeah, you probably don’t need 7 or 8 AMP-hours. That’s just an easy to find bat. But they weigh like 5 pounds. 800mAH is sufficient? I’d think that on the low end... but I dunno... never fired electrically.
Arthur Posted January 21, 2021 Posted January 21, 2021 An important point to remember is that a professional firework igniter fires at about 500mA for 20 milli seconds BUT a DIY igniter may take 2 - 5 amps for a second or two. The psu and the wiring must be up to the firing current required.
Richtee Posted January 21, 2021 Posted January 21, 2021 An important point to remember is that a professional firework igniter fires at about 500mA for 20 milli seconds BUT a DIY igniter may take 2 - 5 amps for a second or two. The psu and the wiring must be up to the firing current required.Fer sher. Were I designing a system the “snake” would prolly be 18 ga. Actually what I might do is use 24VDC as well. That would about halve the current required, therefore the wire size to maybe 20 ga. 20 ga multi-conductor cables ain’t too hard to come by. Might even get away with Cat 6 if yer not running 100 foot of it.
SeaMonkey Posted January 21, 2021 Posted January 21, 2021 Don't forget the Li-Ion cells or batteries.They're a bit more expensive but can deliver a LOT of current. They're also small, lightweight and have remarkable Ampere Hour capacity for their size and weight. The SLA is, however, the best economical choice.
Phil Posted January 22, 2021 Author Posted January 22, 2021 (edited) An important point to remember is that a professional firework igniter fires at about 500mA for 20 milli seconds BUT a DIY igniter may take 2 - 5 amps for a second or two. The psu and the wiring must be up to the firing current required.This is precisely the lesson I'm learning now. I think my igniters are pretty crude(I haven't figured out the pyrogen part yet) and when measured with a multimeter they pulled 1.5 amps with the wall adapter. I could hold the one in the picture for 30 seconds at a time and it wouldn't burn out. I'm guessing this will light anything short of a wet shoestring. (fuses, BP, carpets...) https://imgur.com/lIBSeyF Edited January 22, 2021 by Phil
Phil Posted January 22, 2021 Author Posted January 22, 2021 (edited) Don't forget the Li-Ion cells or batteries.They're a bit more expensive but can deliver a LOT of current. They're also small, lightweight and have remarkable Ampere Hour capacity for their size and weight. The SLA is, however, the best economical choice.Lion batteries like this? https://www.ebay.com/itm/DC-12V-9800mAh-Super-Rechargeable-Portable-Li-ion-Battery-US-Plug-Battery-Pack/382651134655?hash=item5917c8f2bf%3Ag%3ATO8AAOSwSWhc7dR1&LH_BIN=1Duly noted. Edited January 22, 2021 by Phil
SeaMonkey Posted January 23, 2021 Posted January 23, 2021 Question from Phil: Lion batteries like this? That Battery Pack would surely do the job. Its price is surprising. The Lithium Batteries are becoming quite affordable.
WRAITH Posted February 13, 2021 Posted February 13, 2021 For boosting power, try using a voltage amplifier circuit or a plasma lighter circuit as they use only 3.7v, but give a high voltage output (electric arc that burns) or if you are using cheap throw away batteries, i suggest building a small joul thief circuit. You may want to add a capacitor to store more energy & smooth out voltage.
WRAITH Posted February 13, 2021 Posted February 13, 2021 Buy a lipo battery 3000mAh or 5000mAh 11.1v 3S.When fully charged, it should be 12.6v or more. Also depending on the cable length & cable used to your ignition source, low mAh won't have the current there to heat the nichrome. I use light duty speaker cable, not the heavy one, but the regular type & can run it at 20metres without a problem.
Richtee Posted February 13, 2021 Posted February 13, 2021 For boosting power, try using a voltage amplifier circuit or a plasma lighter circuit as they use only 3.7v, but give a high voltage output (electric arc that burns) or if you are using cheap throw away batteries, i suggest building a small joul thief circuit. You may want to add a capacitor to store more energy & smooth out voltage.Just get a fucking gel cell and be done with it. Christ... it’s not rocket science. Well, the ignition part anyway.
WRAITH Posted February 14, 2021 Posted February 14, 2021 A gel cell ? Lithium Polymer 3S 11.1v (LiPo) is the way i go & it's very efficient, but i was just giving examples for a question which needed an answer.
Richtee Posted February 14, 2021 Posted February 14, 2021 A gel cell ? Lithium Polymer 3S 11.1v (LiPo) is the way i go & it's very efficient, but i was just giving examples for a question which needed an answer.Lead/acid sealed cell. But fine... the fancy lithium would work too. My remark is about all the wazoo electronic crap some are trying to use a watch battery to fire an igniter with. Waste of time and money. It IS kinda amusing tho.
WRAITH Posted February 18, 2021 Posted February 18, 2021 Yeah totally agree, but i had to add my 2cents worth given my knowledge in electronics. Also there are some quite disturbing questions in a few topics if you scroll through. 🤣🤣
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