Where do the extra volts go on a regulated 12v system?

[jtexas]

Re: Where do the extra volts go on a regulated 12v system?

LOL where does psi go <br /><br />The pressure upstream from your reducer is still 120, right? The drops of water that would have come through to the house right now have to wait there a little longer for their turn. No water gets wasted.<br /><br />But electrons are not so patient. They will move whether you're ready for 'em or not, or else burn up out of frustration. Hence the need for some kind of heat dissipating device. Wasted energy, unless you're using it to boil the water. <br /><br />Now if your reducer is the type that is actually a hole in the supply line...

 

[Ralph 123]

Re: Where do the extra volts go on a regulated 12v system?

This might help your discussion<br /><br /> http://www.national.com/appinfo/power/files/f4.pdf

 

[beniam]

Re: Where do the extra volts go on a regulated 12v system?

jtexas<br />Whats this about engineers. We care about counting. Theres counting. A counting, the counting and adding on your fingers. Dont see no problems with that. Baffled. Batavier

 

[jtexas]

Re: Where do the extra volts go on a regulated 12v system?

thanks, Ralph, I'd forgot all about those pesky transistors; now that is some kind of magic. Smoke and mirrors, they do it all with smoke and mirrors!

 

[rodbolt]

Re: Where do the extra volts go on a regulated 12v system?

its no worries. trons is simple till ya get to radar and and amplifiers in the giga cylce frequencies. then it becomes super magic. leads me to believe some engineers still use white columbian cystals in their coffee . most simlpe non regulated systems use the strenth of the magnet, the size and amount of the windings coupled with an arbitray battery resistance figgue to calculate charging at WOT. a rectifier can be a simple one diode rig to a 4 diode per phase full wave bridge. modern v6 yams use a 3 phase altenator feeding a 3 phase full wave rectifier with twin taps. thus the built in battery isolator found on most v6 yams since 95 or so. even on those fancy rigs the excess is shunted to ground and the regulator is water cooled. on most flywheel rotor systems the field is non- regulated. and there are no slip rings. they also do not require external excite wires. most do have a sense wire that "senses" system voltage. works ok most the time. the big jonnyrude loopers would light on fire with poor cable connections. so far the yams usually burn a stator winding first. I have seen one 250 yam regulator fire due to a clogged tell tale. so it all depended on how much juice was needed and how clean the rectified current neede to be. the old 3 wire non regulated OMC set ups,like most others, looks pretty nasty on an occiliscope. more like pulsed DC than DC. nice thing about it was it worked

 

[Ralph 123]

Re: Where do the extra volts go on a regulated 12v system?

JT - Since you are interested in this stuff, now that you have Ohms law down, it's time to learn about the next two fundamental laws known as Kirchhoff's Laws:<br /><br /> http://cww.cpcc.cc.nc.us/engrtech/courses/elc133/klaws.html <br /><br />You can then move on to other concepts:<br /><br /> http://cww.cpcc.cc.nc.us/engrtech/courses/elc133/topindex.htm

 

[jtexas]

Re: Where do the extra volts go on a regulated 12v system?

Cool. Actually I embarked on course of self-study a few years ago, to the point of salvaging components from garage-sale VCRs and computers, and putting 'em together in interesting ways that I learned here on solarbotics.net. Always had trouble with the mechanical aspects, though, gearboxes and control mechanisms especially.<br /><br />Then I got the boat which diverted pretty much all my attention. But it's all still in bins in the garage waiting for me to get bored with boating. fascinating stuff.

 

[Paul Moir]

Re: Where do the extra volts go on a regulated 12v system?

... giga cylce frequencies. then it becomes super magic.

I gotta remember that one. <br /><br />Not to completely derail this topic, but does anyone know if the E-tecs use a feild-controlable alternator? I know they must need permanent magnets for starting (they don't need a battery) but they claim a 75 amp output from a "variable voltage, computer controlled" alternator of some sort, which would seem to preclude any sort of linear regulator. <br />I think the 'Computer Controlled' bit might mean they stuck the regulator in the computer box though... <br /><br />Tinkerer - Yeah, that's got it about right, except in addition to the battery turning into a little radiator, it also becomes a little hydrogen and oxygen plant like batavier said. That's why you need to be careful to top up the water on an unregulated system: those H2s and O2s are coming from H2Os in the batt.<br />Although I'll qualify this by saying I've never tried it, I imagine any o/b motor regulator would work so long as it's capacity exceeded the maximum current produced by your outboard. It seems to me that the air-cooled ones would be easiest to fit.

 

[levittownnick]

Re: Where do the extra volts go on a regulated 12v system?

It happened again. It defies the law of the conservation of energy. I tried to add something to this topic and as it turns out, I got more out of it than I could add.<br />Thanks to all participants.

 

[chuckz]

Re: Where do the extra volts go on a regulated 12v system?

Paul is corrected any outboard regulator will work. The regulator technique used is called shunt regulation. The excess current is shunted (or shorted) to ground. The power from this current is dissapated as heat. The higher the output current, the more heat and thus the need for more cooling. Water is about 25 times more efficient at cooling than air. That's why the larger capacity systems are cooled with water. The surface area required to cool by air would be too big to be practical.<br /><br />The output of any rectifier is pulsed DC as Rodbolt said. The batttery acts as the filter to smooth it out to DC. This is another way in which a battery is similar to a capacitor.

 

[rodbolt]

Re: Where do the extra volts go on a regulated 12v system?

so when do we get to DC circuits with an AC signal riding on them ?

 

[levittownnick]

Re: Where do the extra volts go on a regulated 12v system?

To answer the question of when we get D.C. circuits with A.C. riding on them look at any rectified A.C. signal. To help smooth out the rectified signal (D.C.) it needs to be filtered.

 

[Andrew Leigh]

Re: Where do the extra volts go on a regulated 12v system?

Originally posted by Tinkerer:<br /> If a regulator pulls say 16V off the alternator down to say 14V going into the battery, what happens to the excess 2 volts?<br /><br />

You cannot charge a 12V battery at 12V. When the battery is flat it will charge, as it reaches 12V it will cease to charge as the battery back e.m.f. provides resistance to the incoming charging voltage. The moment you don't have a potential difference no current will flow. It is current that charges the battery not voltage. To overcome this back e.m.f. one increases the charging voltage to 13.8 to about 14.4 volts. This creates a potential difference of 1.8 to 2.4V allowing a charging current to flow. This allows each cell to reach 2V fully charged.<br /><br />The current entering the battery (enabled by the 2V potential difference) is released as heat in various components one of which is the battery.<br /><br />As the voltage of the battery get closer to the charging voltage (the battery is reaching a charged state) so the current drops beacause the internal resistance of the battery reduces. As the current drops so does the power consumption and consequently the heat. <br /><br />So when fully charged your battery may well see 16V at the terminals but there will be little current flow and therefor little heat.<br /><br />Anyone?<br /><br />Cheers<br />Andrew

 

[Ralph 123]

Re: Where do the extra volts go on a regulated 12v system?

This should help inform the discussion<br /><br /> http://www.bcae1.com/charging.htm <br /><br />And this:<br />

Charging Current<br />When lead-acid batteries are at a low state of charge, nearly all the charging current is absorbed by the chemical reaction. Once the state of charge reaches a certain point, at about 80 percent of capacity, more and more energy goes into heat and electrolysis of the water. The resulting bubbling of electrolyte is informally called "boiling." For the charging system to minimize the boiling, the charging current must cut back for the last 20 percent of the charging process