Starting Circuit Diode

[dave2374]

Can anyone explain the function of the diode in the starting circuit?

 

[Quicksilver]

Current through a diode can only flow from the anode to the cathodeso in this case starting current [+] can't flow to ground, if it's blown current won't flow anywhere. It seems to be a fixing point, what is the diode attached to (the small ring)?

 

[Texasmark]

Backswing diode for starting energizing coil inside the starting solenoid. V=Ldi/dt. Inductance of starting coil is pretty high to get a good "snap" on the 150 or so starting amperes on the high current contacts. The energy stored in that inductance while energized, is returned to the external circuit in the opposite polarity when the power is removed. This provides a low impedance to ground to prevent negative spikes from occurring on the "switched" 12v circuitry...purple wiring or red with purple stripe. Most electronic circuits that have heavy inductive switching devices have reverse clamp diodes across the coil.

 

[dave2374]

Backswing diode for starting energizing coil inside the starting solenoid. V=Ldi/dt. Inductance of starting coil is pretty high to get a good "snap" on the 150 or so starting amperes on the high current contacts. The energy stored in that inductance while energized, is returned to the external circuit in the opposite polarity when the power is removed. This provides a low impedance to ground to prevent negative spikes from occurring on the "switched" 12v circuitry...purple wiring or red with purple stripe. Most electronic circuits that have heavy inductive switching devices have reverse clamp diodes across the coil.

So, it acting like a surge suppressor?

 

[faztbullet]

[FONT=&quot]This is known as a blocking or quenching diode.[/FONT]

 

[fastjeff]

Temporarily inhibits the flux capacitor from operating.

Jeff