I was involved with the development of a 5 kW hydro-electric power generator in 1985. It has now run for 25 years and I publish this description of the plant to celebrate.
The system consists of several main parts: penstock, turbine, belt transmission, generator, voltage regulator and a frequency controller.
The turbine runner is an old Pelton found behind an outhouse in the area. Water flow is controlled by a needle valve inside the penstock nozzle. The runner drives the generator, a belt transmission is used to increase the speed. The generator is of the synchronous type, the generated voltage level being controlled by varying the field current.
The nominal frequency of 50 Hz is achieved by an electrical controller for the nozzle valve, acting through several intermediate mechanisms:
- The controller drives a windshield wiper motor in an on/off fashion
- The motor drives a sprocket, chain, chainring train from an old bicycle to reduce the speed and bring the motor out of the splash zone
- The chainring shaft drives the pinion of a rack and pinion mechanism taken from a worn out truck
- The rack moves the plunger of the valve
A few photos taken during installation and testing, by Helge Mordt: