Posted by Todd Somers on Sunday, December 28, 2003 at 8:20PM :
In Reply to: Two Electrical Questions posted by Paul(in NY) on Sunday, December 28, 2003 at 7:34PM :
1. A shunt is difficult to build without having a high quality digital voltmeter and ammeter. The basic idea is to have a conductor (usually a piece of brass or copper) that is tapped for leads to the ammeter. This strip of metal also is the conductor for the main current flow as well. In between the taps the shunt is ground away so that a designated amount of current flow can be measured by a voltage drop across the taps. An example would be 5 amps = 1 millivolt. Of course then the ammeter is actually a voltmeter for this setup. It is much easier & probably more accurate to just purchase the shunt & matching meter that you require.
2. I am not familiar with a method of using a Delco SI single wire alternator to drive a tachometer. Alternator tachs are not all that accurate anyway. Belt wear & tension can change the readings. A more accurate and simple method is to use a mechanical drive to turn a pulse generator wich would send a signal to the tach. If the engine you are using is an electronic controled engine, it may hae a tach output available.
Follow Ups: