Dynamo 2 wires connection
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85Hokie
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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Yes, they will have to go to the rectifier to be converted to DC.
What happened to the old dyno? It quit ? Bearings?
How did it hook to rectifier? Got any pictures?
85Hokie
Moderator
Staff member
Lifetime Member
Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
What are the colors of the wires coming off the old dynamo?
here is a similar thread:
http://www.orangetractortalks.com/forums/showthread.php?t=6760
here is a similar thread:
http://www.orangetractortalks.com/forums/showthread.php?t=6760
The windings in the dynamo were touching the body as the ceramic deteriorated. The old dynamo has white, brown and yellow. The new dynamo has both blue. I believe I connect one dynamo wire to the rectifier and the either also goes to the rectifier and bypass the light switch altogether as I don't use these now.
I should post some pics when I get the chance.
I should post some pics when I get the chance.
I remember studying the previous thread including the wiring diagram.
I believe the headlights and perhaps other lights are powered by unrectified alternating current coming from the dynamo. The third wire went directly to the headlight switch
The dynamo produces alternating current in 3 phases. Two phases are sent to the rectifier to charge the battery which can only accept direct current.
Rectifying AC to DC has losses associated with the process in the form of heat and so in the interest of best efficiency not rectifying one phase and using it for the headlights was an efficient design.
The light bulbs are simple resistors which glow when hot producing light and dont care if they receive AC or DC.
I expect the designers of the electrical system planned the size and type of light bulbs to absorb the full output of the unrectified single leg or phase of the dynamo.
Probably the brightness of the headlights changed with engine speed.
If you dont need the headlights then do nothing with the third phase or wire.
If you do then try and find a rectifier which will convert all three phases to DC and connect the headlight switch through a fuse to the battery.
Plse post external views of the old and new dynamo together with any name plate info on them to be certain my comments are correct
Hope this makes sense.
Dave M7040
I believe the headlights and perhaps other lights are powered by unrectified alternating current coming from the dynamo. The third wire went directly to the headlight switch
The dynamo produces alternating current in 3 phases. Two phases are sent to the rectifier to charge the battery which can only accept direct current.
Rectifying AC to DC has losses associated with the process in the form of heat and so in the interest of best efficiency not rectifying one phase and using it for the headlights was an efficient design.
The light bulbs are simple resistors which glow when hot producing light and dont care if they receive AC or DC.
I expect the designers of the electrical system planned the size and type of light bulbs to absorb the full output of the unrectified single leg or phase of the dynamo.
Probably the brightness of the headlights changed with engine speed.
If you dont need the headlights then do nothing with the third phase or wire.
If you do then try and find a rectifier which will convert all three phases to DC and connect the headlight switch through a fuse to the battery.
Plse post external views of the old and new dynamo together with any name plate info on them to be certain my comments are correct
Hope this makes sense.
Dave M7040
Last edited: