The Ossie motor

[futuristic]

So please where is the right place to connect the second scope probe (clip that i hold in my fingers) ?

It seems that - of your probes are on the same potential.

Do it like this to fix this issue:
+ of the first probe put between + of battery and the resistor.
- of the first probe put on the other side of resistor
- of the second probe put on the same spot as - of the first probe
+ of the second probe put on the other side of the coil

This way the voltage on the resistor will show up correctly but voltage on the coil will be shown flipped upside down.
But at least we will be able to see it together.

Frenky

[futuristic]

@Jimboot:

The top scope trace is voltage across resistor and the bottom is across coils?
If so it seems you have big current pulses going back to the battery. It's surface it is much bigger that the one of input current. 

Wow this thread is really amazing.

[neptune]

@Jimboot , re reply 288 . I assume this circuit consists of only a small motor used a generator , a diode and a battery , which is being charged . If you uncouple the generator from the drive , and short the diode , it will cause the generator to spin as a motor . NOTICE WHICH WAY IT TURNS.  Now if you spin it in the same direction as it motors ,  BUT FASTER , it will charge the battery .In other words , provided generator voltage exceeds battery voltage , current will be driven backwards through the battery causing charging . Hence my previous advice to only short the diode after things get up to speed. The diode acts as a resistor , wasting power .
            Re reply 287 . Photo shows meter on 10 volt DC scale . 66% of 10 volts is 6.6 volts . An analogue meter has several scales. Choose a scale that corresponds to the chosen range . So with range switch on 10 volt scale , use the scale on the dial that reads 1 to 10 .  Please reply , telling me if you understand all this 100% because it is VITAL. There is no shame in not knowing , only in not asking .

[woopy]

@ Frenky

back from work  and tried your suggestion   KUDOS    it works fine . effectively my scope probes have the same ground so i have to be very carefull by using canal 1 and 2 together so to not short cut them

And the result is that is no doubt now     each firing of coils comes  from this first wavy and  than spiky pulse.

And of course i am still interested in an explanation !

Just for info those datas are made under    battery 12.2 volts  Rpm at 473  and indicated average Ma at 2.1   that is an input power  of  about 24 miliwatts

good luck at all

and long night to me

regards

Laurent

.

[futuristic]

Great!

Can you please try putting one (schottky)  diode in your circuit.
It would probably help a lot at telling what is going on.

Frenky