I am in the process of designing some electronics and I am looking at power
sources for my application. I am thinking about attempting to take power
from the primary side of a transistorized magneto ignition coil as can be
found on the honda GX160 engines.
My electronic device runs at 3.3v so I need to some how take this AC
current, do some rectifying, smoothing and regulation to generate a nice low
ripple DC voltage of 3.3v. The power requirements are fairly small, I only
need around 200mA maximum
Does anybody know the typical output voltage and current I would expect from
the ignition on something similar to a honda GX160 engine? Power electronics
isn't my speciality, I have done some reading up on the subject but am still
uncertain about exactly what I need to do!
Hai there Steven,
My name's Dilip George and I could say that I have been into
electronics for a long time.First I need to know what is a Honda GX160
engine?.Is it the engine on a bike or a portable generator or
something like that?.The point is,if its of a bike,then chances are
very good that you will have other windings on the magneto to work
on.One winding will be a VERY high voltage coil and is meant for and
can be safely used ONLY for the transistorised (electronic)
ignition.There could be another winding for the headlamps and one more
winding to charge the battery on the bike.Usually, the horn,the brake
lights and indicators are run on the battery.In this case we have a
fairly clean source of DC (maybe 6volts or 12volts) from which it
would be very easy to use a simple transistorized voltage regulator to
get the voltage you need.But then,some bikes don't have a battery and
run everything from the magneto.But even here there will be a
regulator because otherwise all the bulbs will just burn out at high
rev.The voltage after this regulator is really FULL of ripple but you
can easily put a capacitor to smooth it.Just remember that you'll need
to have a diode in between the regulator and capacitor so that you
have an isolation from the rest of the gadgets connected to the
regulator.From here too you can get the voltage you need through a
simple transistorized regulator.BUT if its not a bike engine, but just
a stand-alone engine,then it is very tricky because there would be
only one winding on the magneto and that too would be the high voltage
one.I would never recommend taking a voltage from there.If my guess is
right,you are considering using 3.3volts for a microprocessor chip or
something like that.Do you see any way that you could add one more
coil on the magneto?.Even if there isn't,you could just try and wind a
few turns of good grade enamelled copper wire over the existing
winding so as to get atleast 6volts AC and then take it on from
there.This is also not a recommendable idea if you are meaning to use
a microprocessor because a lot of spikes can turn up in there each
time the spark-plug fires.I know very well that I havn't answered you
question as yet, but then,I can just give you some ideas to work on.If
you need more help,please feel free to write and ask.But in the
meantime,you have some homework to do.Good luck Steven.
