Quick Question

[MadMan]

Well... a new cap didn't help much, but the motor does seem a tiny bit more lively. Also I'm back to not being sure about the diode's purpose. I would think the diode would be to prevent inductive kickback... on a DC motor. It's wired so that Line goes through one half of the field coil, through the diode, to one brush, through the armature, out the other brush, through the capacitor, then through the other half of the field.

So it's like....half wave rectifier??

Meh, it works, that's good enough for now.

[Jon A.]

Originally Posted by MadMan

Well... a new cap didn't help much, but the motor does seem a tiny bit more lively. Also I'm back to not being sure about the diode's purpose. I would think the diode would be to prevent inductive kickback... on a DC motor. It's wired so that Line goes through one half of the field coil, through the diode, to one brush, through the armature, out the other brush, through the capacitor, then through the other half of the field.

So it's like....half wave rectifier??

Meh, it works, that's good enough for now.

If it is a half-wave rectifier it seems like a weak design. If that is the case and the diode were to open the motor would probably go up in smoke pretty quick.

[MadMan]

Originally Posted by Jon A.

If it is a half-wave rectifier it seems like a weak design. If that is the case and the diode were to open the motor would probably go up in smoke pretty quick.

If the diode opened, the motor wouldn't work at all. It's wired in series.
LINE -> field -> diode -> commutator -> capacitor -> field -> NUETRAL

[jr_tech]

The cap is in series with the windings??? I would have guessed that it would have been accross the brushes to suppress RFI.

jr

[Jon A.]

Originally Posted by MadMan

If the diode opened, the motor wouldn't work at all. It's wired in series.
LINE -> field -> diode -> commutator -> capacitor -> field -> NUETRAL

Oh, I thought it was across the terminals. My Ford stereos, certain ones at least have a diode across the terminals of the program select solenoid, I think that's what threw me.