Topic: Possible issues for poor charging..

[PeWe]

That other end can be replaced completely with white connector.
Both my CB750 got new harness from Yamiya, neutral switch wire included that usually are really beaten up after som engine pulls.
New oil pressure harness with rubber cap too.

[Deltarider]

The 3 amps at idle / 2 amps at Rs on 2 3 ohm coils makes total sense. At idle the coil becomes more fully saturated due to the points being closed for a longer period than at higher RPMs so it draws more current. Once the coil is saturated, there is no more energy to store, current goes up  and the coil heats.

 
 Oh... I myself had another explanation. As amps follow voltage, I reasoned that at idle, when the system is at 12V, the amps by nature will be higher than when revved where the system will have 14.5 V. Maybe we're both right. 
On TT's remark:

Most on this forum don't have a clue as to how to measure current in an inductive circuit.

I can only comment that in my understanding there's nothing inductive on the coils +side, where they are fed. But, unlike others here, I wasn't born with all that knowledge, so I'm always open to learn something new. 

[maxheadflow]

The 3 amps at idle / 2 amps at Rs on 2 3 ohm coils makes total sense. At idle the coil becomes more fully saturated due to the points being closed for a longer period than at higher RPMs so it draws more current. Once the coil is saturated, there is no more energy to store, current goes up  and the coil heats.

 
 Oh... I myself had another explanation. As amps follow voltage, I reasoned that at idle, when the system is at 12V, the amps by nature will be higher than when revved where the system will have 14.5 V. Maybe we're both right. 
On TT's remark:

Most on this forum don't have a clue as to how to measure current in an inductive circuit.

I can only comment that in my understanding there's nothing inductive on the coils +side, where they are fed. But, unlike others here, I wasn't born with all that knowledge, so I'm always open to learn something new. 

While on the surface it appears that current dropping as voltage goes up like a switching power supply, it's really saturation time of the coil.  For it to be based input voltage, there has to be some sort of feedback.  A simple coil based system does not have this.  It is basically open loop.     A simple way to validate that current does not drop based on voltage would be to  set a specific RPM or the engine not running and measure the current at 12 volts, then connect a charger that can bring the voltage up to 14.7 and measure the current. You will find that the current increases with voltage.

[TwoTired]

On TT's remark:

Most on this forum don't have a clue as to how to measure current in an inductive circuit.

I can only comment that in my understanding there's nothing inductive on the coils +side, where they are fed. But, unlike others here, I wasn't born with all that knowledge, so I'm always open to learn something new. 

...and that proves my point.  Any coil of wire has inductance.  Actually, even a straight piece of wire does (something quickly learned when trying to push 100MHZ (or higher) pulses down a wire or circuit trace.  In strict DC environments, many of inductive inductive or capacitive effects can mostly be ignored, if you aren't concerned about step response.  But, when AC or pulsed signals are introduced, the frequency determines its effects in a circuit.  The input surge into the coil is certainly inductive, as is the back EMF surge back to the points during the spark event due to the collapsing field.  That's how you get 200+ volts back to the points.

In my experience with you, I'd have to say you don't really want to learn, but rather be spoon fed info qualified to your liking.  Learning often requires objectivity rather than bias.  And this is especially so in electronic matters.  It is quite often non-intuitive...until you gather advanced concepts.  I see little evidence that objectivity is part of your make up.  You reject info that doesn't meet with your "intuitive sensibilities".  Sad really.

[PeWe]

Positive thing with these discussions is the explanations about how it works, maybe not needed today but might be useful when issues arises.

[Deltarider]

...and that proves my point. 

As if that was your point... Anyway, my simple test is valid and has demonstrated that in practice power comsumption at the coils is less than some here warn for. An that happens to have been my point.

[scottly]

It's such a simple test that I invite anyone to check my findings or - even better - post the results with standard 4,7 Ω coils.

I did this test some time back: at idle speeds, the current draw was about 2.5 A, and decreased to about 1.5 A at higher RPMs.

[Deltarider]

It's such a simple test that I invite anyone to check my findings or - even better - post the results with standard 4,7 Ω coils.

I did this test some time back: at idle speeds, the current draw was about 2.5 A, and decreased to about 1.5 A at higher RPMs.

With standard coils, Scottly? And just to make sure: in total for the two of them?

[rotortiller]

Anyway, my simple test is valid and has demonstrated that in practice power consumption at the coils is less than some here warn

And there lay the problem, some people do not like to be corrected while others gladly consume measured data. As a matter of fact your general findings of reduced power consumption at rpm are supported by many' testers'. There are enough 'why' articles online explaining  common factors and to assist the layman's  design, basically  factors relating to coil selection (dwell and saturation implications).

[scottly]

It's such a simple test that I invite anyone to check my findings or - even better - post the results with standard 4,7 Ω coils.

I did this test some time back: at idle speeds, the current draw was about 2.5 A, and decreased to about 1.5 A at higher RPMs.

With standard coils, Scottly? And just to make sure: in total for the two of them?

Yes, two stock CB750 coils, points, and condensers, point gap at the nominal .014", 12.4 V applied to coils from battery during test.

[Deltarider]

That leaves me to conclude that my 3 Ω coils (combined) draw only some 0,6 A more than stock. Not much to speak of...