I have seen a simpler system: simply a (higher voltage) light bulb across the same phase of the two generators. When the generators are at different frequencies, the light flickers. When the frequencies are closer, the flicker slows down. When both are at the same frequency but different phases the light stays steady. When at the same frequency and phase, the light stays off. Isaac Em 8/5/2011 22:00, Richard Prosser escreveu: > On 9 May 2011 12:38, Bob Ammerman wrote: >> ----- Original Message ----- >> From: "Justin Richards" >> To: "Microcontroller discussion list - Public." >> Sent: Sunday, May 08, 2011 10:25 AM >> Subject: Re: [OT]:how are hydroelectric power stations synchronised >> >> >>>> I once saw a generator being switched on line at a hydro power station= in >>> I would like to see that. >> I used to develop control software for hydroelectric plants. The basic w= ay a >> generator is synced in manually has been well described here: a device >> called a synchroscope displays the phase relationship between the grid a= nd >> the generator. The 'scope looks something like a clock with a single han= d. > ..snip....... >> -- Bob Ammerman >> RAm Systems >> >> >> > > IIRC the earlier model of the "synchoscope" used two schyncronous > motors - one driven from the grid and the other from the local plant. > The motors were coupled to a differential gear (like a cars diff - but > smaller) which driectly connected to the indicator. Frequency > difference was indicated by a moving indicator and phase difference > could be read directly as an offset from vertical provided the motors > were near - identical. > > RP --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .