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TTAC’s own Ronnie Schreiber writes:
Sajeev,
How many spark plugs do you think a Model T “trembler” ignition coil can fire simultaneously?
I’m foolishly trying to make a spark plug-based Chanukah menorah (candelabra), so I need to have as many as nine plugs sparking at the same time. I could use individual coils but those run about $100 each and I don’t want to spend a thousand bucks on this project.
Yes, I know the voltages are dangerous.
Sajeev responds:
I’m not surprised you asked me this, and let’s not dwell (sorry) on the imminent danger of an ignition system-based menorah.
Henry Ford’s possible objections notwithstanding, using Model T tremblers for a spark plug menorah is doable. But since the Model T needed one trembler for each plug, you could need 9 of them. While I can’t find the trembler’s specs, judging by the YouTube videos, they sure look powerful (and dangerous). Maybe one could power two plugs! But while they are cheaper than full retail on a modern coil, they ain’t cheap.
Unless you have used tremblers lying around, what’s stopping you from buying used coil-on-plug units? They are under $40 at my nearest junkyard, but I guess it won’t look as cool as nine big boxes mounted remotely from the menorah.
I’d probably just stick with candles.
What say you, Best and Brightest?
[Image: Ford]
What in hell are we suppose to make of this? :(
Everyone knows Chanukah was over weeks ago
There’s another one comin’ round.
In what, 10 months? Have you thought about your Christmas decorations for this year yet? I guess the tech nerds will be all over this anyway ;-)
my what?
For a moment there, I thought I’d experienced “lost time” and this the first of April.
:-O
Knowing radical Ronnie there’s more to this then Henry Ford’s invention being the lighting source of a menorah, but maybe not ;-)
I have no suggestions. This is uncharted waters for me.
TTAC, Sajeev,
If Ronnie is successful, can you run a short blurb with a few pictures? Id like to see the finished product.
You’re not going to need the same amount of current in this use as you would in a working engine. The spark produced in an ICE engine has to survive the onslaught of compression, which snuffs out less-than-fully-powered sparks.
In the open air, at 1 bar, the sparks will not need as much juice.
How about a nice NIXIE menorah?
Can be done.
You need a small neon sign transformer and you’ll have to wire the plugs in series and insulate them for 10kV, which is not as bad as it sounds – just don’t get too close and don’t leave it unattended. You’d have a continuous arc, and a pleasant smelling ionization to the room air! Wouldn’t cost much.
The only purpose to using Model T parts for a menorah is to have Henry Ford spin in his grave to be remotely involved in celebrating a Jewish holiday.
Ding ding winner matzah balls for you.
Bingo!
90 minutes into the post before someone could connect the dots!
No, I picked-up on it right away, but I’m not sure of the purpose of stirring this particular pot of a man who’s been dead for 73 years
Worth it for this alone, and I’m an atheist.
I get the Henry Ford angle (and please, one didn’t have to read beyond the headline to get it), but wouldn’t 1948 Buick components be more fit for purpose? See http://www.macsmotorcitygarage.com/buick-portholes-a-10-minute-history/
Instead of automotive coil(s), consider starting with the transformer from an old microwave oven (see “Jacob’s ladder” projects on youtube). Continuous vs. intermittent sparks could open a whole religious debate (but intermittent would lose).
With multiple air gaps, series vs. parallel is a potential question but has a predictable answer (some say).
DANGER symbol: Don’t die.
WARNING or CAUTION symbol (which to choose?): Don’t start generating large amounts of ozone.
Dust off your gap tool.
Extra credit:
a) GFCI won’t save you – or could it?
b) AFCI won’t power this device – or would it?
c) Isolation transformer at the head of the chain – any benefit?
Update: Did some more ‘research’ (starting from zero lol) into trembler coils and I now understand your intent.
The trembler coil generates a continuous series of sparks – no timing signal needed.
Watched a trembler cross a ~1 inch gap, so yes it should cross 9x spark plug gap if wired in series. Question now is would the resultant sparks be of equal intensity so as to provide maximum aesthestics – and hypothesized answer is “yes” if the respective gaps are managed properly.
Update to the update: The resulting sparks might be equal in intensity regardless of the respective gaps – see the *video* here (multiple gaps in series across one spark plug):
https://www.briskusa.com/brisk_multi_spark_plug_multi_spark_spark_plugs
If this is correct, you could manage the brightness of the whole device by adjusting only one spark plug gap (larger gap = brighter).
Definitely avoid using a microwave oven transformer for this type of project! MOTs output around 2.2-3.5 kV at 200-400 mA, which poses a fantastically high risk of electrocution. Also, because of the high current capability the arcs will be VERY hot (extreme overkill for this purpose, and a fire hazard) and will produce sufficiently copious ozone to trigger acute respiratory problems in many individuals. Finally, the amount of RFI this would likely generate could lead to someone filing a complaint with the FCC!
In theory, one could mod a MOT and add some external circuitry to tame the beast a bit and reduce the risk, but I’d still steer clear.
A somewhat safer approach would be to use a neon sign transformer, which typically output roughly 6-18 kV at 15-30 mA (depending on the specific unit). This will produce a nice arc but will not likely source sufficient current to maim, burn, or kill (however, if you go higher than about 20 kV @ 30 mA the risk of sending at least 50 microamps through the heart and causing a lethal shock increases significantly). Unfortunately, all NSTs made since the early 90s feature current-limiting and ground-fault protection so they are unsuitable for generating arcs.
The safest approach by far (but most complex) would be to build a circuit to drive a flyback transformer, which would give enough voltage for a nice blue-purple arc but would be limited to a few mA at most. A shock from this would certainly get your attention, but not be much more dangerous than a vigorous static discharge.
Agreed that the microwave oven transformer was a bad idea – thank you.
(The trembler coil might be just about perfect.)
If the plugs are wired in parallel, only one will fire, whichever has the narrowest gap. When this plug’s gap wears another plug will take over and so on. Wiring the plugs in series, as Imagefont suggests would solve this problem but is more complex to implement.
You can’t fire more than 2 plugs with one coil simultaneously. If you hooked them all up to a single coil you would have one that sparked, as the electricity will take the path of least resistance. So head to the wrecking yard and grab some Ford waste spark coil packs. One from an early 4.6 and one from a later Vulcan. Each coil will fire 2 plugs, one in the standard center electrode to side electrode and the other from the side electrode to the center electrode.
That is why those cars left the factory with one part number for the spark plugs for bank 1 and one for bank 2 as they just put the platinum on the electrode that the spark “leaves” from.
Since you’ll have 5 coils you’ll have to pick one for a “bye” and connect one of its terminals to ground.
The next problem is each coil will need its own circuit to fire it.
Oh and I’m not sure why you think you would spend $1000 on doing it with individual coils. Coils are cheap, no where near $100 each.
Here is a 10 pac of genuine Motorcraft coils and plugs. For $156 https://www.amazon.com/Motorcraft-Straight-Ignition-Compatible-3L3E12A366CA/dp/B07786QG62/ref=sr_1_1?keywords=ford+coil+set+of+10&qid=1582300971&s=automotive&sr=1-1
Or if you don’t mind white box parts you can get a 10 pack of coils by themselves for under $50.
But then there’s the question of authenticity. In this application, the Model T trembler coil would maximize the value that counts: the RPM of Henry spinning in his grave.
Yeah a set of tremblers would be better for that purpose. But at least he could use Motorcraft if he goes modern.
When I was a kid, I heard stories about home made car anti-theft devices using a Model T “coil box,” must have been a trembler. A nasty experience for anyone touching a metal part of the car. And being stupid teenagers we’d laugh about a dog taking a whiz on a hubcap. Never saw one, don’t know if it was real, or just an apocryphal story told by teenagers.
Sajeev and Ronnie, now this is quality content.
Is there an electrical engineer in the house?
Cause a simple AC circuit and flickering bulbs is just too easy.
Never underestimate human capacity to over engineer while waiting the needle swing back to simplicity.
If Ronnie combines a trembler coil with an Arduino (or ATtiny) + wireless shield + relay, we will be making progress.
Because touchscreen.
IoT FTW, Ronnie!
What an interesting project .
‘T’ Model coils (“buzzer boxes”) require _very_ low current as they were operated by 4 (IIRC)1.5 volt CD door bell batteries until the engine started and the magneto in the flywheel began to produce current .
Yes, the anti – theft stories are true as well as using these coils on toilets to shock the living hell out of anyone pissing or sitting….
No one died from the low current .
I hope this gets built and a photo or link to one is posted .
Using the modern Ford coils and a vintage wooden boxed one in view would work very well , kinda cheating but the desired result would be the same in the end, use only OEM Ford branded coils of course .
-Nate
At atmospheric pressure, you can probably daisy chain them together in a “waste spark” configuration and then just use a regular coil.
The problem is more on how are you going to keep them all fired up at all time without burning out anything.
Daisy chain might work.
But whatever you do, I think you might want to consider lampshades on each plug. I don’t think unshielded arc light is a good idea for the eyes of your family.
Level I (safer than candles): Get a 10-light LED “chaser light” soldering kit; relocate 9 (or 8) of the LED’s to the inoperative spark plug gap spaces. Enjoy the [silent and safe] “Knight Rider” effect.
https://www.youtube.com/watch?v=WxE2xWZNfOc
Level II: Obtain one (and only one) trembler coil. Obtain and assemble a “Velleman K8044: 10-Channel Light Effect Generator Kit” and link 9 (or 8) of the relay outputs to the spark plugs (each lead to each relay, common ground). Enjoy the “Knight Rider” effect but with sparks instead of lights. Since the plugs fire sequentially, the original question of ‘how many can fire simultaneously’ is moot, and the duty cycle on the single trembler coil will be as per original design intent.
Level II omitted “add relays” step. :-)
And likely “fry relays” – “redesign using distributor or old-school Edison-style design of rotary contacts (which will experience sparking wear).”
Probably better to stick with simultaneous firing?
I considered suggesting an electric motor spinning a V8 distributor, but then I thought about the Hz required for a pleasing visual effect (estimated 30 Hz*60sec/min = 1800 RPM) and decided that it might be loud and/or wear out quickly.
Why not tesla coils?
“Anything worth doing, is worth doing right.”
Is this the first question asked by an official Schmuck?