Three Y-axes?

In Calc, how can I add three data series with very different vertical ranges to the same Line-chart or XY-chart?

In one example, I have voltage from 0…200, current from 0…10 and power from 0…2000.

In another example, I have radiant power from 0…1e-3, counts from 0…65536 and ratio from 0…65.

One workaround I can think of is using two axes (which I know how to do) and rescale one of the three series using an extra column (for example, dividing power by 10). The downside is that the units displayed in the chart are deceptive. Another alternative is using multiple charts, which I think is even worse, since the graph lines can’t be visually compared, which is the whole point of charts.

No AFAIK. The only workaround would be to use relative units (i.e., in range of 0-100% of the maximum value). That isn’t an answer, just a workaround, not necessarily suitable.

(Line charts not being of x-y-types are generally misleading.)

In one specific case, also concerning electric circuitry many years ago, I introduced an extra axis by overlaying a second chart and making it transparent. This wasn’t that extremely cumbersome as it may sound. It was a ticklish case of layouting, however, and will need manual adaptions in many cases of changing values, not to speak of changing data ranges.

However, I don’t think I can find that example again to demonstrate the technique, and I wouldn’t create another one now.