Linear voltage regulator?

Are you charging a 12V car type battery?
I think a person can only produce about 100 watts.

A linear regulator will not work in this application for two reasons.

1. At low speeds, when the generator output voltage is below 14 V, a linear regulator cannot boost it up to 14 V. There are switching regulators called "buck-boost", that can move seamlessly between boosting an undervoltage and bucking (regulating down) an overvoltage. Linear Technology (now a part of Analog Devices) is big in this arena. Know that this is not a trivial design project at low power. At 350 W it is a difficult design project.

2. If the generator can produce 350 W at 24 V, regulating that down means dissipating 146 W. That's a lot.

Please add some details to your question. At what bike speed does the generator output drop below 15 V? When producing 15 V, how much current is available?

ak

ronsimpson said:

Are you charging a 12V car type battery?
I think a person can only produce about 100 watts.

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I seem to recall that a fairly fit man can only generate about 60/70W for any decent period of time, with 100W been more of a short time peak. The simple 'test' was usually powering a 60W bulb

Top cyclists can generate more for long periods though - and the guy who cycled over the English Channel on a pedal powered plane was particularly impressive

A 350W alternator would seem pretty pointless, and produce less power than a more sensibly sized one.

10W load will feel like a significant drag on your speed and likely make you not reach your goal.

Even the friction of trying to spin it to max RPM with pulleys will be a challenge to your strength and be an uphill battle.

With out knowing what is powered by the 14 volts we cannot say what to do. Charging a battery is very different than a heating element or running a car radio.
At this point, we all agree you will never get 350 watts. Not close.
We mostly agree "linear regulator" will waste power.
I cannot comment more because we don't know enough and guessing adds confusion.

Nigel Goodwin said:

I seem to recall that a fairly fit man can only generate about 60/70W for any decent period of time, with 100W been more of a short time peak.

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50 to 150 W for us mortals. To get the Gossamer Albatross across the English Channel took around 1/4 horsepower continuously for over two hours.


ak

14 yr old boys can possibly charge up a flashlight with one hand for hours after 15 minutes of vigorous exercise.

However your concept is not sufficiently thought out.

In my former city there was a museum exhibit with a hand crank AC generator and gearbox with three 20W light bulbs in parallel as a load. The idea was to crank the generator up to some comfortable speed and switch the lightbulbs on one at a time. When the third one was switched on there was noticeable difficulty in continuing to crank. It was very difficult to continue for more than a minute. Legs might be better than arms but there are still enormous obstacles to using human power to generate electrical power.