If we compare it to water, volts would equal pressure and amperes would equal gallons per minute. The flow determines how big a hose you need, just like a thicker wire allows more amps, but the pressure (volts) has no impact on how big a hose you need, just on how strong the hose (or electric insulation on the wire) has to be to avoid "leaks" - you know how ignition wires carrying around 20 000V. has thicker insulation than the low voltage wires.
37kid, think of a wire as a hose. Take a 1/2 inch garden hose, if you have 40 psi it will give you 100 gallons per minute ( power)of water. Now increase your pressure ( volts) to 80 psi and you get 200 gallon per minute ( power)of water through the same hose. Edit: those figures are just examples. Bones
G-son, I have heard that OEM is going to 24 or 36 volts. I know it has to be true..... because I “ heard it” . Lol Bones
Too many watts is responsible for wires getting hot. Low volts, high watts. High volts, low watts. I don't understand it either. What I want to know is, can you have as good of an ignition system what's 6 volts as you can with 12 volts? Even though pranking it might not work out too well, as Jim was saying. But I wonder if it could be done? I guess I have this idea of the err err err of a laboring starter motor and then the engine exploding to life. Just for the nostalgic effect. Probably a dumb idea. Sent from my VS835 using The H.A.M.B. mobile app
hybrids are running a couple hundred volts, but that's a whole different subject. Diesels work good on 24 volts, and some military vehicles have had 24v systems for quite a while. I don't worry much about it, I think we'll be able to buy 12v batteries for quite a few years yet.
The ballast resistor turns a 12v ignition system into a 6v ignition system, mostly...but not quite. The bypass wire gives it 12v while cranking. Interesting idea, perhaps a 6v CD ignition system would help? but maybe if it's cranking slowly, that's why it's not starting right away. it's not the ignition system's fault.
Going to higher voltages on new cars was a consideration a few years ago, but the advent of LED's and other low current devices has made it unnecessary.
I remember hearing rumbles about 48 volt systems or even higher on the horizon several years back, maybe in Popular Mechanics though nothing since that time. All those butt warmers and steering wheel heaters, outside mirror defrosters, windshield, navigation aids etc., starts to add up I guess.
Heard it in the 90s. Still not holding my breath waiting for it. A capacitor discharge ignition charges a capacitor to a few hundred volts and then suddenly dumps the charge through the ignition coil to make a spark, present day electronics should have no problem boosting a low voltage such as 4V to 2-300V to charge a capacitor. I wrote 4V to account for the voltage drop under high load, as when starting. It can be done at lower voltages too, but as many types of electronics require a few volts before they can work at all it becomes more difficult as the voltage goes down. Not impossible, just more complicated and expensive. A transistorised points ignition should work good too, but perhaps not as good. If you use a conventional bipolar transistor you loose about 1V there, so the issue with low voltages mentioned above becomes obvious. If you only have 4V and loose another 1 in the electronics, there's not much left to produce the spark once it gets to the coil.
I though I had it pretty well figured out at one time - the OEM made the switch to 12 volts, though they left the ignition system alone, mostly. Dropping resistors in the instrument cluster. But some 6 volt cars used a ballast resistor too??
Like Squirrel, said most vintage 12 volt ignition systems actually run on about 6 volts. So the spark should be the same. But consider that the coil( transformer) takes 6 or 12 volts up to ultra high voltage, around 20,000 volts on the lower end to 60,000 or more on the higher end to make the spark. It really doesn’t make much difference if you start with 6 or 12 volts as long as you get to the 20 to 60 thousand volt level. ....... Just food for thought. Bones
That's kind of what I figured... that the 6 volt ignition system wouldn't really be a problem. Would have to rewind the 12-volt starter to run it on 6 volts. And then there's the accessory issue. Yup... dumb idea. Nevermind. LOL Sent from my VS835 using The H.A.M.B. mobile app
Well... Yes and no. It takes a while for the current to rise to the max level through an ignition coil, or anything else that creates an electromagnetic field - it takes a while for the magnetic field to build, and that causes it to take a while for the current to rise too. If you give a (6V) coil with a 1 ohm primary winding 6V, it will eventually let through 6A, but at first it may only allow perhaps 1A through. Take that same coil, add a 1 ohm ballast resistor and feed it with 12V and you will eventually get that same 6A, with 6V on the coil and 6V on the resistor. BUT, here comes the big difference, the initial high "resistance" of the coil causes most of the voltage to go to the coil, and just a little over the resistor, say that the coil initially gets 10V and resistor 2V. This gives the coil a bigger initial "kick in the butt", giving it a higher initial current, reducing the time it takes to reach max current = reducing the time before the coil can produce a spark of maximum intensity. In short, it can handle higher rpm, or at least keep producing stronger sparks as rpm increases. As a bonus, you can feed the coil full battery voltage w/o going through the resistor at start, to make very strong sparks when battery voltage is the lowest. So while 6V ignition systems may be similar to 12V systems ballasted to theoretically 6V at the coil, they DO have big differences.
I understand, my point was it will work about the same for a street engine. High performance is another thing. Talk to us about the condensers job in the ignition system. I kinda thought it made up for voltage. Or something like that. I know without the condenser the system won’t work , hardly at all, 6 or 12 volt. Bones
Well, the condenser… That puts us at the other end of the period current flows through the coil, i.e. when the points open and stops the current from flowing. Just like the beginning when it takes a while to build up the magnetic field & electrical current, it takes time for it to stop. The magnetic field can cause a short pulse of several hundred volts to build in the primary winding, in an attempt to keep pushing current through - if the current can keep flowing, that would keep that voltage peak down. With nothing to hold it back, the early voltage increase is more than enough to start an arc at the points when they've just opened, small opening arcs at relatively low voltages. Current can keep flowing for a period at a low voltage, the energy stored in the magnetic field is "slowly" bled off and you don't get a spark. A condenser, or more properly capacitor, connected over the points lets a little current to keep flowing for a short time, as the capacitor is charged up (they basically work as a chargeable battery). This takes a fraction of a second, not much but enough to let the points open far enough - when the voltage goes all the way up to several hundred volts there is (almost) no arc at the points, the opening is too big. This is when the ignition coil works as a transformer, the few hundred volts in the primary winding induces a voltage perhaps 100 times higher in the secondary winding, if it has 100 times as many turns. 200 volts in the primary winding times a hundred gives you 20 000V out of the secondary winding, to the spark plugs.
I initially was going to swap to 12v for a stereo system, but a nice bluetooth speaker carries that load, and even though quality sound is important in my daily, I hardly listen to music in the 54'. The 6 volt pos ground seems to be working fine on my bucket. I expected it to be an issue at some point, but it hasn't. The only time I had a dead battery was not long after I bought it and got it running somewhat decent. The battery was just old, but I jumped it off from a 12v truck without issue. The GEN or OIL lights were the only thing that could have come on but we were quick and no burnt bulbs or battery explosions. I keep a spare juiced battery in the trunk and I found a Die Hard 6v/12v charger/starter at Kmart when they were going out of business.....got it for $40 and its in the trunk too. Since I am prepared, it'll probably never be an issue....Isn't that usually how it works? I kinda like the sound of the ol' starter with 6 volts. Sounds like a grumpy old fart muttering to himself. Like the car is pissed that I've awakened it from its slumber.
Thanks, it always kinda freaked me out how the coil fires when the points open, not close, completing the circuit. Seems kinda odd. I’ve been involved is businesses that use electric clutches that have big coils on them to activate the clutch plates. We have to put diodes to ground to keep them from spiking the electrical system with huge voltages. In the old days the systems could take that momentary high voltage....... not so theses days. Again thanks for that explanation. Bones
It may indeed seem odd, until you know how it works. It takes a while to build up the energy charge, in the form of a magnetic field, the energy is released when the field breaks down because the current stopped. It's like a hammer, it does nothing while you swing it to give it energy in the form of speed, the energy gets released when something gets in the way and suddenly tries to stop the hammer. Hopefully not your thumb.
G-son, I like the way you explain things! I knew that about the coils.... but here In Oklahoma the light bulb comes on when you close the switch...... just kinda hard for this Okie to wrap his head around the thing working when you open the switch! Lol Bones
The Jalopy Journal
