Electronic Ignition

[Bob_Roller]

Anyone know what the power comsumption of the OEM electronic ignition system is ?

Trying to figure out how much of the charging system output I am using .

Using two 55 watt driving lights all the time, I'm quite sure I am taxing the charging systems capabilities .

The last time I had the diode board removed, the fiberglass board the diodes are mounted on, were blackened for about .5 inch (12mm) around the diodes, I'm sure it is going to be the first component to fail .

Weighing the cost/benefits of an upgraded charging system, or just replace the diode board with one of the new type boards, like Thunderchild, or the Omega board from Motorrad Elektrik .

The bike just gets general utilitarian usage, no long trips .

[Barry]

Anyone know what the power comsumption of the OEM electronic ignition system is ?

No but I know that my points based ignition draws an "indicated" 4 amps at idle which reduces by 0.5 amp or so as the engine revs increase. It's about what you would expect from 2 x 1.5 ohm coils but the figures are a little higher than the real average current.

Assuming you have 2 x 0.75 ohm coils or a single 1.5 ohm you should be drawing double the current or maybe a little less depend on whether the electronic ignition box has any sophisticated dwell control that interrupts the current once coil saturation is reached. I don't know for sure but suspect the earliest type did not.  

I measured mine a few years ago when I fitted the points amplifier. I just pulled one of the coil wires off and put an ammeter in series. There will be some ambiguity about measurement accuracy because your not measuring flat DC current. The ammeter will be trying to average the current pulses as the coil charges to saturation and then discharges every time the plugs fire. Some meters will just measure the peak current giving you a high reading.

If you really want to get technically into the difference between ignition coil peak current and average current read Tony Foales ignition article http://www.tonyfoale.com/Articles/Ignition/Ignition.htm

[Bob_Roller]

Thanks Barry, so a figure of 55 watts should be close enough for my use .

So, if my figures are close to real world use, I'm using 235 watts out of a maximum available 280 watts, but probably less due to 31 years of usage and system degradation .

So at highways speeds, the best possible scenario is 4 amps available to charge the battery, but more likely less than that .

I need to get a voltmeter wired directly to the battery and get out to see what my voltages are in my usual riding conditions .

I haven't had any problems with battery charge, but I put a battery maintainer on the battery whenever the bike is parked for the day in the garage .