Help with a missing diode.

[WHX?? 46,814]

On Sylvia's @SylvanLakeWH NOS A-60 Electric  Horse a PO decided he needed the plastic block that plugs into the ignition switch more than this tractor does. No biggie as @Achto found a replacement in the jungle & one will be here today. 

Worst is there is a diode that plugs in a socket that is wired in the motor circuits that run the mower blades. That diode has also flown the coop and is listed as discontinued. 

Can anyone tell us what the purpose of that diode is? It appears it's part of the power supply to the DC motors. Perhaps a braking circuit when the blades are switched off? 

Part number for it is 104272. 

Also part number for ignition switch is 104270. Is this switch the common five terminal one found on other models? 

 

Mods if this thread belongs in electric horses please move. 

Edited March 29, 2023 by WHX??

[gwest_ca-(File Mod) 10,503]

May help? There is a switch schematic.for 104270

 

[WHX?? 46,814]

Thank you Garry was looking for that. 

[Handy Don 10,634]

Probably not blade braking, but I think you are on the right track.

I think it prevents current from being put back into the circuit from blades that continue to spin after the motor is shut off.

[953 nut 51,775]

Most DC electric motors will also act as a generator. When the switch is turned off the blades spin for a while and will slow more rapidly if there is opposition to the power being produced by the blades spinning the motor. I don't think it is a deal breaker, with the holder for the diode being open it will do no harm in my opinion.

[Achto 26,573]

57 minutes ago, WHX?? said:

That diode has also flown the coop and is listed as discontinued.

 

One of these work for you Jim?

 

[WHX?? 46,814]

Yes that's where I was going with this but thinkin it would help if a guy knew the electrical characteristics or ratings of it. 

I'm going to get in touch with a guy that I met at a show who is into GE Elect Tracs. See if he can shed any light on this. Get some numbers off the motors & research them too. 

[SylvanLakeWH 24,175]

If i'm understanding this then, you can run without a diode? My simplistic brain assumes the closed switch prevents current from blades still spinning from going back into the circuit past the closed switch???

[gwest_ca-(File Mod) 10,503]

[gwest_ca-(File Mod) 10,503]

Trying to figure out the ignition switch wiring and I'm stumped. This is from the E-81 that used the same ignition switch

[squonk 38,965]

The direction arrow on the diode is allowing current out of the mower motor to the motor switch but not from the switch to the motor. I think it's there to keep that motor from going in the wrong direction. 

Edited March 29, 2023 by squonk

[WHX?? 46,814]

Mower switch is a three position spdt switch & has continuity from white to red/white in run. White to black/white in momentary start mode, spring return to run when released. 

[WHX?? 46,814]

43 minutes ago, squonk said:

The direction arrow on the diode is allowing current out of the mower motor to the motor switch but not from the switch to the motor. I think it's there to keep that motor from going in the wrong direction. 

So they are looking for some sort of feedback from the motor? Why only to one motor? 

The white wire is connected to the violet one when the ignition switch is in start or run. 

Continuity from the red wire on the ig switch to dk blue when in start is the only other ring on the switch.  

Edited March 29, 2023 by WHX??

[squonk 38,965]

Just now, WHX?? said:

So they are looking for some sort of feedback from the motor? Why only to one motor? 

The white wire is connected to the violet one when the ignition switch is in start or run. 

No idea why. But all a diode does is prevent current flow in the opposite direction of the arrow. They wanted it in there for some reason. I'm not an electrical engineer. I just watch guys play the part when they come to do a power survey at the plant.  Maybe that feed back to the switch acts as a blade brake when the switch is flipped off. 

[WHX?? 46,814]

42 minutes ago, squonk said:

blade brake when the switch is flipped off. 

My first thoughts too and the motors see each other somehow thru the mower solenoid? 

 

42 minutes ago, squonk said:

I'm not an electrical engineer.

Well go get one dammit ... 

Sure wish Save Old Iron was still around... 

 

This should work for the ignition switch... 

Edited March 29, 2023 by WHX??

[953 nut 51,775]

52 minutes ago, WHX?? said:

Sure wish Save Old Iron was still around.

           He was great to have on the site, love to use his posts an an answer to  questions if I don't know the answer.

 

[SylvanLakeWH 24,175]

All i can say from afar is "thank you gentlemen!!!" My little filly is getting remarkably good care and feeding.., 

[WHX?? 46,814]

40 minutes ago, 953 nut said:

           He was great to have on the site, love to use his posts an an answer to  questions if I don't know the answer.

 

He sure was Richard... only guy I know that would take a regulator apart to just to see what made it tick. 

 

36 minutes ago, SylvanLakeWH said:

All i can say from afar is "thank you gentlemen!!!" My little filly is getting remarkably good care

No problem yer just lucky it's crappy and cold out and I wanna work in a nice warm shop.

If I can get Dan off a barstool long enough to come over we might try and put 36 volts on her and run some motors. 

36 minutes ago, SylvanLakeWH said:

and feeding

Looks like someone was doing that before... noticed straw down around the bottom of the batteries...  It was obviously stalled in a barn at some point. 

Tire got fixed and holding air fine... old lady was gettin back problems moving it... 

Edited March 29, 2023 by WHX??

[SylvanLakeWH 24,175]

Carnac sees into your future...

 

 

 

 

 

And it is good... 

[gwest_ca-(File Mod) 10,503]

Interested in knowing how the terminals on the ignition switch are identified when viewed from the back.