The post describes an alternator or generator power booster circuit, Let's find out more about the .
The circuit seems to be a straightforward AC voltage booster. The main part which can be to blame for providing the excess power is the high voltage capacitor C1 which charges up with each AC cycle and reverts the power by means of the switching triac into the linked load.
The load thus gets added power due to the switching high voltage capacitor by way of the triac.
The triac is usually a BTA41/600A, which replies and switches ON the moment the diac fires. The minimum voltage necessary for the diac to fire is around 30 volts.
The above idea may also be used with the following circuit which happens to be less complicated than the above and is also very much cheaper.
The capacitor ratings might be altered and tried as per the load, and individual choices.
However this circuit can be utilized only for heater applications such as irons, heaters, geysers, ovens, toasters, blowers, dryers, hot air gun etc.