99yam ?

[boscoe99]

Sinusoidal AC.
Maybe charge coil signal is not a smooth sine wave?

Could be that is the situation.

[boscoe99]

I always thought the cap, diode, and resister was to build up and hold the charge voltage long enough so the meter could see it better.
anyway you look at it, if they set the specs minimum with using the special peak reading meter, I am not sure you can use anything else to compare to the spec voltages

higher RPM means a lot higher frequency as those magnets fly by the coils

My first thought was if the frequency is involved. From reading what I can find, a sine wave is a sine wave and frequency does not matter. Does not affect the ratio of peak voltage to RMS voltage. But...

[99yam40]

My first thought was if the frequency is involved. From reading what I can find, a sine wave is a sine wave and frequency does not matter. Does not affect the ratio of peak voltage to RMS voltage. But...

just strange that @ 1500 RPM I read 237VDC with my adapter and on AC with just my voltmeter set to AC I read 61 - 65 VAC
At around 3500 on DC with adapter I read 162 VDC and on just my meter set at AC, 59VAC

trying to understand why
I will try that again tomorrow and try measuring Peak also with My F 87
not sure why lower RPM would show higher DC V

if more High peaks I would expect a higher reading

Just had a thought, maybe I did not see a 2, but a 1
tomorrow while I am washing the boat after a fishing trip I will get more reading

[99yam40]

OK I just checked the 1500 RPM readings again and they were the same as before
meter set to AC without adapter = 60.1 VAC
meter on dc with adapter = 237VDC

set my fluke 87 on AC and hit the peak & min Max buttons : min -038.8 and Max 205.2

so, to me this says you will not get a reading you can compare to the spec in manual by using a regular volt meter without and adapter.
and even my peak reading meter( not the one for reading these ignition systems) will not give you the same reading as a proper peak reading meter or a regular meter and an adapter

[boscoe99]

I am not understanding.

[zenoahphobic]

A number of points.
What comprises the adaptor? the capacitor has parameters that affects what the meter reads. It is dependent on frequency, on it’s designed operating voltage and amount of leakage. You are almost guaranteed by changing this capacitor your readings will change.
However I think (intimated earlier) the output is not a sine way but rather pulses. The output is dependent on the amount of iron in the coil (s) and the amount or strength of the magnet and their separation. You will reach a saturation at some point where clipping of the wave will occur. And your regulator will shunt to ground.
All would be much better to use an oscilloscope (Crt ) but there are probably Apps for smart phones available today. You can only get some approximation with digital and digital displays.
I would worry about high voltage readings, shows you that a 12v generating system can electrocute (zap you unexpectedly). I guess the reason behind calling for peak voltage readings, not only to highlight possible danger, but alert that arching and insulation breakdown are possibilities.

[99yam40]

I am not understanding.

ok what are you not understanding?

I thought I followed your request to take some readings on the motor with a regular meter and then with an adapter and the regular meter

[99yam40]

A number of points.
What comprises the adaptor? the capacitor has parameters that affects what the meter reads. It is dependent on frequency, on it’s designed operating voltage and amount of leakage. You are almost guaranteed by changing this capacitor your readings will change.
However I think (intimated earlier) the output is not a sine way but rather pulses. The output is dependent on the amount of iron in the coil (s) and the amount or strength of the magnet and their separation. You will reach a saturation at some point where clipping of the wave will occur. And your regulator will shunt to ground.
All would be much better to use an oscilloscope (Crt ) but there are probably Apps for smart phones available today. You can only get some approximation with digital and digital displays.
I would worry about high voltage readings, shows you that a 12v generating system can electrocute (zap you unexpectedly). I guess the reason behind calling for peak voltage readings, not only to highlight possible danger, but alert that arching and insulation breakdown are possibilities.

I am not sure if you understand that the charge coil is not for charging batteries, it is what produces ignition voltage to send to the coils to create spark plug spark

[zenoahphobic]

Right you are 99yam, wasn’t clear at first. Down south charging coils are lighting coils. My wrong.
Doesnt change what I wrote much except the spark plugs only require short bursts in the cycle and I guess the term charging is used to describe the electric field building up again between sparks.
So maybe still pulsing not sinewaving. And because the lighting coils share the same magnet(s) they may have some erratic influence.

[99yam40]

I believe they are called charging coils because they are what charges up the capacitors in the Capacitor Discharge Ignition systems

[boscoe99]

ok what are you not understanding?

I thought I followed your request to take some readings on the motor with a regular meter and then with an adapter and the regular meter

I am not understanding the results. Does not seem reasonable to me. 237 DC volts. Something is going on that I don't or can't understand. Yet.

[boscoe99]

C40 tune up specs.

[99yam40]

I was chasing a high speed miss years ago, so I built this adapter to get some readings.
when my readings were way higher than what the specs said, I questioned Rodbolt, about what is too high.
he said there is no too high, just too low.
the specs are minimum

did you notice that higher RPM has lower minimum spec?
I though that was strange also

As I said I compared my readings to a meter that I borrowed from a retired marine tech, and they were very close.

turned out a previous owner of this motor drilled out the main jets.
put in new ones and my high speed miss went away
so I did not have a problem with the ignition system after all

[boscoe99]

Just ordered a peak reading adapter. Will see what I can see.

[zenoahphobic]

If you really want to see buy a LCD oscilloscope. My EBay has them at $100 the size of a multimeter and can be used as such.
No guessing, a graph of many readings taken over time not just a snapshot.
Simply look at the scale to determine the peak….and gives you a whole lot of other information about the waveform.