FSH 210 Sport
Jetboaters Admiral
- Messages
- 6,389
- Reaction score
- 7,551
- Points
- 447
- Location
- Tranquility Base
- Boat Make
- Yamaha
- Year
- 2020
- Boat Model
- FSH Sport
- Boat Length
- 21
I decided to make this post here as opposed to the electronics section since it is on the engines and not accessory devices.
As some of you may know I come from an electrical field background, see what I did there? A little electrical systems humor.
As such, I wanted to make a separate post about our charging systems, equipment definitions and how things work with our charging systems as I see some terms misused and I have probably used the terms incorrectly myself to simplify my posts but have been trying to make sure I use the terms correctly, as well as misconceptions about how our systems operate.
Firstly, our systems are alternators not generators. They are called alternators because they produce AC voltage / current, and in the case of our alternators they produce three phase voltage / current, whereas generators produce DC voltage /current. These alternators in our boats are made up of the following components;
Stator. The stator is the stationary winding that is mounted to the engine, you can gather why it is called a stator, right?
Rotor. The rotor is the flywheel that is attached to the crankshaft of the engine, it has magnets embedded in it that create the fixed magnetic field (flux density) that spins inside of the stator. This spinning magnetic field is what “induces” voltage into the wires of the stator, or induction, and because the north / south poles of magnetic field pass across the same area’s of the stators winding, this creates voltage flow that is both positive and negative and that is how AC current voltage is made. And because the magnetic field is fixed, they are referred to as PMA or permanent magnet alternators.
Rectifier / Regulator; The Rec/Reg in our boats are what is known as a full wave, three phase short regulator rectifier. You can read about the different Reg / Rec here; Regulators/Rectifiers | Motorcycle Products | SHINDENGEN ELECTRIC MFG.CO.,LTD. These Reg/ Rec convert the AC voltage from AC to DC through the use of diodes, and then a variable gate shunts unwanted voltage and current to ground. NOTE: In an automotive style alternator the AC voltage is converted to DC voltage the same way using diodes, but the regulation is accomplished by varying the strength of the magnetic field on the rotor, these are VMA or variable magnetic field alternators, this is the same way that voltage / power output is regulated on large utility scale generators, home generators etc. The stronger the magnetic field (flux density) is on the rotor the more power output a given generator will have because there are more lines of magnetic flux passing over the wires of the stator. The advantage of a PMA style alternator is that it will create “power” whenever it spins whereas the automotive style has to have voltage / current on the rotor to make the alternator work, this is why in a car if the battery voltage is so low or has a short that after the engine is jump started the engine will die because there is not enough voltage to maintain the magnetic field in the alternator. The disadvantage of a PMA is that it does not have as much output as a VMA.
In a PMA the power output is always at maximum, this is why the Reg / Rect is always warm / hot to the touch even when the batteries are fully charged and no accessories are on with the engines running.
The power output on the 1.8L and 1.04L TR-1 engines is roughly 14 Amps per engine. The most I have observed flowing into my house battery has been 13 amps per engine for a total of 26 amps in my twin TR-1 engined boat. I welcome any observed output number from the 1.8L engines but I believe they have the same output. Having said that, the more accessories one has on, the less charging amps one will see going into the batteries.
Maximum output of our alternators happens at 3500 rpm on up. I have observed the maximum output at idle is 7 Amps per engine when the battery is low and tapers off a lot as the battery gets near full charge, this is due to the charging profile of the Reg / Rect for lead acid batteries to keep from boiling off the electrolyte.
As some of you may know I come from an electrical field background, see what I did there? A little electrical systems humor.
As such, I wanted to make a separate post about our charging systems, equipment definitions and how things work with our charging systems as I see some terms misused and I have probably used the terms incorrectly myself to simplify my posts but have been trying to make sure I use the terms correctly, as well as misconceptions about how our systems operate.
Firstly, our systems are alternators not generators. They are called alternators because they produce AC voltage / current, and in the case of our alternators they produce three phase voltage / current, whereas generators produce DC voltage /current. These alternators in our boats are made up of the following components;
Stator. The stator is the stationary winding that is mounted to the engine, you can gather why it is called a stator, right?
Rotor. The rotor is the flywheel that is attached to the crankshaft of the engine, it has magnets embedded in it that create the fixed magnetic field (flux density) that spins inside of the stator. This spinning magnetic field is what “induces” voltage into the wires of the stator, or induction, and because the north / south poles of magnetic field pass across the same area’s of the stators winding, this creates voltage flow that is both positive and negative and that is how AC current voltage is made. And because the magnetic field is fixed, they are referred to as PMA or permanent magnet alternators.
Rectifier / Regulator; The Rec/Reg in our boats are what is known as a full wave, three phase short regulator rectifier. You can read about the different Reg / Rec here; Regulators/Rectifiers | Motorcycle Products | SHINDENGEN ELECTRIC MFG.CO.,LTD. These Reg/ Rec convert the AC voltage from AC to DC through the use of diodes, and then a variable gate shunts unwanted voltage and current to ground. NOTE: In an automotive style alternator the AC voltage is converted to DC voltage the same way using diodes, but the regulation is accomplished by varying the strength of the magnetic field on the rotor, these are VMA or variable magnetic field alternators, this is the same way that voltage / power output is regulated on large utility scale generators, home generators etc. The stronger the magnetic field (flux density) is on the rotor the more power output a given generator will have because there are more lines of magnetic flux passing over the wires of the stator. The advantage of a PMA style alternator is that it will create “power” whenever it spins whereas the automotive style has to have voltage / current on the rotor to make the alternator work, this is why in a car if the battery voltage is so low or has a short that after the engine is jump started the engine will die because there is not enough voltage to maintain the magnetic field in the alternator. The disadvantage of a PMA is that it does not have as much output as a VMA.
In a PMA the power output is always at maximum, this is why the Reg / Rect is always warm / hot to the touch even when the batteries are fully charged and no accessories are on with the engines running.
The power output on the 1.8L and 1.04L TR-1 engines is roughly 14 Amps per engine. The most I have observed flowing into my house battery has been 13 amps per engine for a total of 26 amps in my twin TR-1 engined boat. I welcome any observed output number from the 1.8L engines but I believe they have the same output. Having said that, the more accessories one has on, the less charging amps one will see going into the batteries.
Maximum output of our alternators happens at 3500 rpm on up. I have observed the maximum output at idle is 7 Amps per engine when the battery is low and tapers off a lot as the battery gets near full charge, this is due to the charging profile of the Reg / Rect for lead acid batteries to keep from boiling off the electrolyte.
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