Puppeteer

Author Topic: Alternator Hz tip  (Read 364 times)

Jordan

  • Jr. Member
  • **
  • Posts: 67
    • View Profile
Alternator Hz tip
« on: June 23, 2019, 11:02:10 AM »
I heard a suggestion for fine-setting of engine speed to obtain the required Hertz.

Assuming pulleys of theoretically near-correct ratio are installed on engine and alternator shafts:
Paint a white line on the alternator pulley, so that with a lamp shining (powered from grid, on a house circuit for example) the line will appear stationery when correct speed is achieved.
It's the same principle that was often seen on hi-fi record player turntables.
Has anyone else heard of this method?


mike90045

  • Mendocino Metro
  • Hero Member
  • *****
  • Posts: 1378
  • Mmmm BBQ
    • View Profile
    • Mikes Solar PV page
Re: Alternator Hz tip
« Reply #2 on: June 23, 2019, 11:01:55 PM »
But that requires you have stable Grid power to check it with.   Which is fine if you are on grid.  I use the frequency meter on my inverter to set no-load to 63hz, and full load ends up at 58hz

BruceM

  • Hero Member
  • *****
  • Posts: 2751
    • View Profile
Re: Alternator Hz tip
« Reply #3 on: June 23, 2019, 11:16:42 PM »
It's going to be difficult to use an incandescent bulb as a strobe; there is too much heat retention in the tungsten filament, even with a dark room.   Buy the tachometer.

Jordan

  • Jr. Member
  • **
  • Posts: 67
    • View Profile
Re: Alternator Hz tip
« Reply #4 on: June 24, 2019, 01:54:21 PM »
I've gotta try it, as all it needs is to paint a line on the pulley.
It would be fun if it works (maybe better under fluoro light?), and could be handy as it's always there.
I shall report!

Johndoh

  • Hero Member
  • *****
  • Posts: 643
    • View Profile
It is better to light a candle than to curse the darkness

Jordan

  • Jr. Member
  • **
  • Posts: 67
    • View Profile
Re: Alternator Hz tip
« Reply #6 on: June 24, 2019, 11:32:23 PM »
Don't panic, folks. There needs to be a white line on the alternator pulley for my digital tacho anyway. :)
I also have a frequency meter, which will look in keeping with the old genset.


sirpedrosa

  • Sr. Member
  • ****
  • Posts: 338
  • Just one more day hoping to hear that sound
    • View Profile
Re: Alternator Hz tip
« Reply #7 on: June 25, 2019, 12:53:22 AM »
Hi Jordan

It's not a white line, its a refletive stripe, in order to reflect laser beam to reader.

And, yes, that digital it is fairly accurate.

BR
VP
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx

glort

  • Hero Member
  • *****
  • Posts: 2977
    • View Profile
Re: Alternator Hz tip
« Reply #8 on: June 25, 2019, 08:19:17 AM »

I would be measuring the frequency off the generator output.  This will take into account all variances like pulley wear and give you an absolute speed/ frequency.  Having a Multimeter fetish I know there are a load of meters available cheap as chips from China with frequency which are all amazingly accurate. You should be able to get one for $10.

The panel frequency meters aren't expensive either.
Meters are better, simpler and more accurate than anything else I can think of.

old seagull man

  • Full Member
  • ***
  • Posts: 112
    • View Profile
Re: Alternator Hz tip
« Reply #9 on: June 25, 2019, 09:01:41 AM »
Buy yourself one of these and connect in to the generator output.
The 20Amp version has its own internal shunt so the power go's straight through it at all times and you have volts, Freq, watts, Kwh, amps, all for less than the cost of a few beers.
Got 4 of them on things. I know Glort collects them.

https://www.ebay.com.au/itm/AC-110-250V-100A-Digital-LCD-Panel-Meter-Monitor-Power-Energy-Ammeter-Voltmeter/323753388465?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

38ac

  • Hero Member
  • *****
  • Posts: 1812
    • View Profile
Re: Alternator Hz tip
« Reply #10 on: June 25, 2019, 11:19:50 AM »
There is no doubt that your idea will work but as has been said by the others with all the cheap meters around why bother?  I have two Kill O Watt meters that I bought when they were $12.  They are $30 now but there are cheap alternatives on Ebay.   I keep one near the set and the other one is used at the house and is used to monitor loads.
Collector and horder of about anything diesel

Jordan

  • Jr. Member
  • **
  • Posts: 67
    • View Profile
Re: Alternator Hz tip
« Reply #11 on: June 25, 2019, 01:04:30 PM »
Here's my portable meter box, apparently made for servicing small gensets according to the leaflet that came with it.
I found it at a swap meet.
It's plugged into a house power outlet, switched on but with no load attached.
« Last Edit: June 25, 2019, 01:11:18 PM by Jordan »

Johndoh

  • Hero Member
  • *****
  • Posts: 643
    • View Profile
Re: Alternator Hz tip
« Reply #12 on: June 25, 2019, 10:32:10 PM »

I would be measuring the frequency off the generator output.  This will take into account all variances like pulley wear and give you an absolute speed/ frequency.  Having a Multimeter fetish I know there are a load of meters available cheap as chips from China with frequency which are all amazingly accurate. You should be able to get one for $10.

The panel frequency meters aren't expensive either.
Meters are better, simpler and more accurate than anything else I can think of.

Good advice from Glort I took his advice on a multimeter 12 I think it cost and it does as much and more than my local sparks very expensive Fluke multimeter
It is better to light a candle than to curse the darkness