Pot set to 68k

 

That's weird... thats 60Hz 'hum'... where are you probing? Can you show me the breadboard for this 555

 

Look back a few posts I just dumped a few pictures

 

Probe was set to OUT pin

 

Sorry I had to step away and go get my son from practice.

 

That's weird... thats 60Hz 'hum'... where are you probing? Can you show me the breadboard for this 555

I swear I took pictures of the board and posted them but I don’t see them.

 

missed this one.... a signal generator giving +/- 6v square wave at 50Hz?

Or another 555! Replacing the pot with a 68K gives 1000rpm approx.

View attachment 275355

This is the circuit I built and sent pictures from.

 

So tomorrow I can stay late in the lab. Kids get the bus home. I’ll also bring the gear home so I can putter on Saturday. This is probably a bad case of me not using the digital scope correctly.

 

1000rpm approx.

While 1000RPM or even 500RPM may be the flywheel speed, it isn't the actual ignition or firing speed. This is a hit and miss engine, it has a governor that regulates the RPM output, after it fires the plug it may coast for a while to keep the speed constant, without firing the cylinder. All depending on the load on the output.
https://en.wikipedia.org/wiki/Hit-and-miss_engine The governor was typically like the fly ball type used on steam engines.

 

While 1000RPM or even 500RPM may be the flywheel speed, it isn't the actual ignition or firing speed. This is a hit and miss engine, it has a governor that regulates the RPM output, after it fires the plug it may coast for a while to keep the speed constant, without firing the cylinder. All depending on the load on the output.
https://en.wikipedia.org/wiki/Hit-and-miss_engine The governor was typically like the fly ball type used on steam engines.

I agree
That’s how it’s supposed to be
The governor rod was removed when this electric ignition module was installed. It runs pretty consistently- there is nothing to mechanically disengage the spark because it does not use the internal magneto. This is an add on magneto and magnet trigger.

now we are attempting to take it farther and get rid of the magneto and only use the magnet mounted the flywheel and the pickup coil to trigger a DC (solar and battery only) CDI circuit.

 

The governor rod was removed when this electric ignition module was installed. It runs pretty consistently- there is nothing to mechanically disengage the spark because it does not use the internal magneto. This is an add on magneto and magnet trigger.

If that's where your going with this, I hope you have experience pouring and scrapping babbitt. Those engines were never meant for continuous firing.

 

This is it at a high rpm…

https://share.icloud.com/photos/082kA9_GF43hba5p9hpuuoPsQ

It runs like this for 24 hour at a time a few days a week.

 

Any opinions on this scope?

DEVMO Digital Oscilloscope Kit 2.4" TFT Handheld Pocket-Size DIY Parts Fully Assembled Electronic Learning Set https://a.co/d/3nUdH3s

 

So, from the linked video we now know the engine is firing at ~5Hz. That's useful for the circuit design process.

 

So, from the linked video we now know the engine is firing at ~5Hz. That's useful for the circuit design process.

I used a stroboscope and a meter connected to the flywheel to determine it typically runs at 425 RPM. One fire per revolution.

 

Breadboard set up

 

Here we go this AM

It’s kinda noisy

 

This looks better

I added a resistor between the trigger and the scope

Now this is with an Inverted scope

 

HV scope:

 

Breadboard set up

Looks OK as far as I can see...

Any opinions on this scope?

DEVMO Digital Oscilloscope Kit 2.4" TFT Handheld Pocket-Size DIY Parts Fully Assembled Electronic Learning Set https://a.co/d/3nUdH3s

Personally I think these are a waste of time, however if its all you can afford.... I'd save up for the next level up around $150

a resistor between the trigger and the scope

Hmmm not sure why that's made a difference... do you mean between the 555 output and the 'scope?