I apologize for completely going off on a tangent on this, but I have understood the efficiency of electrical mechanical devices since an early age. Most people will want to skip the rest of this post, but if anyone is interested... here is why.
As a child I was fascinated by human powered energy production. Not as a means of providing the world with useful power but to understand intrinsically the amount of muscle power needed to power various devices. Over the years I have had a large collection of hand and leg cranked generators and wind up devices.
As a childhood project I connected an old car generator to a stationary bicycle. There were inefficiencies in the system I designed but unlike an alternator the generator was self exciting and needed no battery so the load placed on the system was directly transmitted to the pedals of the stationary bicycle. I used the generator with both a voltage regulator and without a voltage regulator.
Unregulated my system put out about 50 volts when the bicycle cranks were rotated at approximately 100 rpms. The 50 volt output was more than enough to power handheld electric drills and other tools powered by AC/DC brushed motors like blenders, mixers, grinders etc... It was very interesting to me at the time that placing a load on the drill could be felt positively and immediately by whoever was pedaling the bicycle. It felt like a direct mechanical connection and to me at the time this was an indicator of the efficiency of electro-mechanical devices.
I performed many other “experiments” using the generator with and without a voltage regulator. If the system was used with a voltage regulator it could be pedaled at a slow speed and still maintain 12 volts. If a load consisting of 12 volt electric light bulbs were connected in parallel... One 60 watt bulb was fairly easy to keep lit, two 60 watt bulbs required significant effort for most people, and three 60 watt bulbs was more than most people could keep lit for any significant amount of time.
The interesting thing about the bulbs connected in parallel with the voltage was regulated that it was easy for the peddler to find what RPM was most comfortable to maintain their most efficient output at a certain energy production level. This was faster pedaling than most people realized it would be especially at higher loads.
I actually was a state champion and nationally ranked bicycle road racer in the late 1970s. The lesson learned about the efficiencies of pedaling at a higher cadence was something that helped me especially when planning gear ratios for hilly routes. Most other racers tried to climb hills at that time with as high a gear as they could handle, but I always felt that this was inefficient because of my experiments with a load with a regulated 12v output.
So sorry for the long explanation and going off on a tangent.
I am sorry these were 100 watt light bulbs.