New question for Ron
 

Ron. I obtained this doc' on charging systems. Can you explain the difference between "current reg" and "voltage reg" on the voltage regulator in reference to the three relays.

(couldn't attach the doc')

To elaborate, Terminal B+ is cut out relay. Terminal DF Current regulator
Terminal D+ voltage regulator.
Can you explain please the function of each relay.

Arcturus;

I have careful reviewed the article...it is generally good and consists of much good and valid info...the only minor issue I have with it is where it states in the second paragraph: "When the armature spins in the magnetic field, the windings in the armature have a voltage induced in them"...more correctly, it should state: "have a current induced in them"...this is a point of physics, but since voltage and current are related, the author mixed the terms...again, otherwise it is a good article, and good reading for anyone wanting to understand their Chg Sys better.

To answer your question...Voltage Regulation is when the VReg monitors system voltage and when low, enables Charging System to generate and contribute power...which pulls up system voltage as it recharges Bat and powers loads. Current Regulation is rather a safety function of the VReg...it monitors the Gen output current and if too high (so that it might damage Ch Sys) it has the ability to decrease the (Field) energization current, which in turn, backs down the Gen output and lowers the stresses put on it...it may therefore take longer to recharge a highly discharged Bat, but that is always preferable to overloading the Gen and risking damaging it...

Hope that helps... Cheers

Sorry Ron - but voltage is correct. V = N d(phi)/dt, as Faraday might have said if he'd had to do it on a keyboard :)

(Consider the case when there is no load connected - no current flows, but you get the voltage anyway.)

Pigeon;

I tried to answer arcturus' question and explain things in an understandable manner...you and I can have a theoretical discussion beyond that, but it will surely be lost on non-engineers...as I noted...V and I are (very!) related, and in your special example of an open circuit, clearly there can be no current flowing as there is no complete path (i.e. "circuit"), so the voltage will certainly build and one could say "voltage is induced".

As engineers, I think we understand each other...I was always taught, and come back to the term "current is induced...", as it is presented in theoretical discussions, such as here: https://www.khanacademy.org/science/...ng-electricity

Cheers

Whilst we are on the subject of electrics, I am having some problems with my lights. i think that the dip switch may be faulty. When I connect my volt meter to the power terminal I get 6+ volts from the other terminal that supply's power to the lamp,main for example. The other terminal out to dip shows .06v. Is that enough leakage between terminals to cause a problem or is it negligible? This is on both main and dip positions. Should I replace the switch?

arcturus;

That "leakage voltage" is a mere 1% of the system voltage and nothing to be concerned about!...if the voltage was to increase to something more substantial, the Dipper Switch is not what I'd suspect first, but the chassis connections at the headlights! This would be an example of voltage drops due to a poor chassis connection causing an inadvertent circuit interaction...I'll see if I can sketch up an explanation...

Cheers

Thanks. i know that you provided me with a fuse size calculator some time ago but can't find it. Can you please send repeat. Thanks.

Indeed you can't get current ( flow ) started without voltage ( pressure)
but you can get voltage without current .

I had a battery failure where it still showed 12.6 volts but could only supply about 8 amps. The nice AA man sold me a new battery.

arcturus; See: http://www.sw-em.com/Fuses,%20Alloca...m#Fusing_Rules

Clan; ...but Current is what does the work...no current, no work...perfect example is Derek's duff bat.

Derek; The Voltmeter you measured that Bat with, drew an extremely low and insignificant amount of current, so it measured the surface charge voltage just fine...but once the significant current required by the Starter is drawn (and we want to do some work), voltage collapses to nothing...that is why a Load Test is what should be performed on a Bat...it takes into account the internal resistance of the Bat...which should be quite low, so that when high current is drawn, only very little drops across its own low internal resistance, and almost all voltage occurs across Load...

Cheers

I would use the term potential until a circuit is made.

Ron. The AA man did the proper tests and repeated them about half an hour later. Left engine running and then switched off and tried a start. Would barely click the solenoid. He'd had a cup of tea sheltering from the pouring rain at the hairdressers where I'd taken my mum and sister. Was my sisters AA account. Alternator was working normally.

So, worked out fuse rating for headlamps. 2x60w. 120/6. x 1.25. =25.w. fuse. is that correct?

arcturus;

I'm not sure where you got the 1.25 factor (1.5 to even 2 is a good factor range for incandescents because of their inrush), and your results would be in Amps, and that would then be used as fuse rating...so short answer is: Not quite.

Looking at what the factory did as a reference: In wiring diagram of a 6V 444 (http://www.sw-em.com/444LS%206V%20Wiring%20Diagram.gif), we see 45W/40W Headlight elements (7.5A/6.6A), and a single 25A fuse upstream of the Light Switch. Nominal current calculates at 15A/13.2A (1.6/1.9 Factors)

Contrast that to the 6V 544 WD (http://www.sw-em.com/544_6Vwiring.jpg) where Headlights of similar wattage ratings are individually fused at 8A, so the factor there works out at only 1.06/1.2. (I'd be mildly concerned and on the lookout for fuse "nuisance blows" with those low factors, but I'm sure factory engineers found those values to be OK, showing judgement and actual test experience is also taken into account when specifying fuse currents!).

So long answer (taking into account standard fuse values) is...if fusing individually for 60W, I'd recommend 12 or 15A, and if fusing together, I'd use 25A or even 30A (assure wire gauge is suitable for expected normal condition current!).

Hope that helps.

i am using 2.5 gauge wire. 2x60w bulbs on one fuse for the time being. I will be altering to 1x60w with 112amp fuse, when i get another fuse block. The w/v x1.5 I plucked from the internet I am using H4 6v 60/55w P43T light bulbs

arcturus;

You should double-check the charts to see if 2.5mm2 wire has a suitable cross-sectional area for the expected current, but otherwise that sounds OK.

Cheeers