I consider this a repair, so hopefully im putting this in the right section.
On some other post i mentioned that i had replaced the original 'voltage regulator' with a small bridge rectifier and solar charge controller, but i didn't have any pics of that and kinda felt bad about leaving that 'unsupported'. Well, i've done it again and took pictures this time!
Disregard that mess of tiny lithium batteries for now, but if you're interested i wrote about that on another forum here and will probably post about it on this forum when it's 'done done'.
As far as the charging system, these tractors have a 'dynamo' which is basically some magnets glued to the inside of a pulley which spins near a stationary coil of wire. This creates AC (alternating current) voltage. Batteries are DC (direct current). To turn AC into DC you have to pass it through some diodes in an arrangement called a 'full wave bridge rectifier'.
Like this:
That's the little square box with the male spade terminals on it. If you buy them in bulk they are only a few dollars a piece. I believe that one is rated for 35a.
For the record, stator is referring to the 'stationary winding' which your dynamo leads are the two ends of. Electrically the dynamo is just one long piece of wire that goes in behind a pulley, turns around a bunch of loops forming a 'coil', then comes back out. The pulley has magnets in it and would be called the rotor because it rotates, thus the rotor/stator abbreviations. The only variable in how this thing works is the engine rpm, so your AC voltage coming out will rise and fall with engine rpm. I have read that it should be about ~28v AC at max throttle, and i believe it is normal that it will be below 12 (ie not high enough to charge the battery) until you are at about 1/3rd to 1/2 throttle. In other words, no charging happens at low idle and i believe that is a normal condition.
So you put the AC from your dynamo through there and get some pulsating DC. That then becomes the 'solar' hooked to a small solar charge controller.
At cheapest those can be about $8-9 (the one pictured on my tractor is $16) and they are basically a little electronic brain that compares the higher voltage of its input ("solar") to the lower voltage of its output (battery) and rapidly turns a switch between them off and on (called PWM or Pulse Width Modulation) until the voltage of the battery rises to a setpoint (which is usually adjustable). They usually do 'multi-stage charging', with adjustable voltage setpoints for the different phases like 'bulk, absorption, float' which im not going to get into here. Main point is it's adjustable. They also sometimes have 'load ports' which can control some external circuit/device based on voltage setpoints. I did not use that here.
So, this whole bridge rectifier + solar controller thing just replaces the stock non-adjustable voltage regulator with an adjustable voltage regulator which gives you the option to ALSO power it with a small solar panel on the tractor as a 'battery maintainer', which my tractor has, and also use the 'load ports' to add control/safety to some other circuit. It's definitely not for everyone, but it does work and for some people might offer some advantages such as being able to adjust voltage to switch to lithium batteries, or mixing power from multiple charge sources. It doesn't offer any inherent functional advantage vs the stock stuff when on a stock tractor. I don't recommend you do it as any kind of 'upgrade' unless electrical is just a hobby or interest of yours, like it is mine.
Anything with a similar charging system could use this (even a riding mower) although anything with a 3-wire stator would need a different rectifier brick with more terminals (it would be a 3-phase full wave bridge rectifier).
I love a tractor thread with pictures of tractors, so here are pics of both tractors I have done this on. My friend's has the backhoe, i fixed that one up in this thread.
Mine has the belly mower on it in this pic (usually 60" box blade as loader counterweight) and you can just barely see the 5w solar panel i have under the seat which gets sun when the tractor is parked because i always park it with the seat bungied up to the steering wheel.
On some other post i mentioned that i had replaced the original 'voltage regulator' with a small bridge rectifier and solar charge controller, but i didn't have any pics of that and kinda felt bad about leaving that 'unsupported'. Well, i've done it again and took pictures this time!
Disregard that mess of tiny lithium batteries for now, but if you're interested i wrote about that on another forum here and will probably post about it on this forum when it's 'done done'.
As far as the charging system, these tractors have a 'dynamo' which is basically some magnets glued to the inside of a pulley which spins near a stationary coil of wire. This creates AC (alternating current) voltage. Batteries are DC (direct current). To turn AC into DC you have to pass it through some diodes in an arrangement called a 'full wave bridge rectifier'.
Like this:
That's the little square box with the male spade terminals on it. If you buy them in bulk they are only a few dollars a piece. I believe that one is rated for 35a.
For the record, stator is referring to the 'stationary winding' which your dynamo leads are the two ends of. Electrically the dynamo is just one long piece of wire that goes in behind a pulley, turns around a bunch of loops forming a 'coil', then comes back out. The pulley has magnets in it and would be called the rotor because it rotates, thus the rotor/stator abbreviations. The only variable in how this thing works is the engine rpm, so your AC voltage coming out will rise and fall with engine rpm. I have read that it should be about ~28v AC at max throttle, and i believe it is normal that it will be below 12 (ie not high enough to charge the battery) until you are at about 1/3rd to 1/2 throttle. In other words, no charging happens at low idle and i believe that is a normal condition.
So you put the AC from your dynamo through there and get some pulsating DC. That then becomes the 'solar' hooked to a small solar charge controller.
At cheapest those can be about $8-9 (the one pictured on my tractor is $16) and they are basically a little electronic brain that compares the higher voltage of its input ("solar") to the lower voltage of its output (battery) and rapidly turns a switch between them off and on (called PWM or Pulse Width Modulation) until the voltage of the battery rises to a setpoint (which is usually adjustable). They usually do 'multi-stage charging', with adjustable voltage setpoints for the different phases like 'bulk, absorption, float' which im not going to get into here. Main point is it's adjustable. They also sometimes have 'load ports' which can control some external circuit/device based on voltage setpoints. I did not use that here.
So, this whole bridge rectifier + solar controller thing just replaces the stock non-adjustable voltage regulator with an adjustable voltage regulator which gives you the option to ALSO power it with a small solar panel on the tractor as a 'battery maintainer', which my tractor has, and also use the 'load ports' to add control/safety to some other circuit. It's definitely not for everyone, but it does work and for some people might offer some advantages such as being able to adjust voltage to switch to lithium batteries, or mixing power from multiple charge sources. It doesn't offer any inherent functional advantage vs the stock stuff when on a stock tractor. I don't recommend you do it as any kind of 'upgrade' unless electrical is just a hobby or interest of yours, like it is mine.
Anything with a similar charging system could use this (even a riding mower) although anything with a 3-wire stator would need a different rectifier brick with more terminals (it would be a 3-phase full wave bridge rectifier).
I love a tractor thread with pictures of tractors, so here are pics of both tractors I have done this on. My friend's has the backhoe, i fixed that one up in this thread.
Mine has the belly mower on it in this pic (usually 60" box blade as loader counterweight) and you can just barely see the 5w solar panel i have under the seat which gets sun when the tractor is parked because i always park it with the seat bungied up to the steering wheel.
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