As you might know me and my friends love riding our old isms on mopeds which as you can see after over 30 years of usage still work without a problem, but The electrical system of one of them is a bit weird Since it uses around 12 volt AC RMS for the headlights While the rest of the electronics is built around the six volts DC battery The problem is that 6 volts is not very useful if you want to connect modern appliances Because 12 volts is nowadays D standard Now, of course,
we could buy ourselves a more or less easy to install 12 food conversion kits, but that is a bit expensive so in this video let’s find out how the electrical energy of such a mopeds is created lets do easy to find parts to convert the old 6 volt system into a 12 foot one Let’s get started This video is sponsored by jl CPCB This a new full automatic PCB batch production factory is being used since april They produce 600,000 square meter of PCBs per month at low price $2 To start off we removed the mounting screws on the right side of the engine block.
Thus reveal the electric generator of the mopeds now mo-bet is start and accelerating with the fault level we can see how the red part of the generator starts spinning While the insights which apparently consist of 3 coils stay in place The red part of the generator which in my example here is black is called a magnet wheel Which lightly name applies consists of 6 magnets? positioned in a circular order To understand the generator principle a bit better though I also created an example coil by winding enamel copper wire around a ferromagnetic material After a few dozens of turns.
I cut the wire Lets connect both side of my new coil up to the oscilloscope and then place the coil inside the magnet wheel which I then rotated as You can see on the oscilloscope. ac voltage is come proportional to the revolutions per minutes of the magnet wheel and this is no wonder because the induction law states that a voltage is induced into a coil if there is a changing magnetic flux going through its which it is because of the six moving magnets and disconnect my oscilloscope connect led let check ,
it work We can create electrical energy just like the moped does So for the next steps I firstly got myself a circuit diagram of the Sims own to find out that we got one coil for the headlights One coil to charge the battery and power the back lights and one for the motors ignition points Those coils feature one common star point tied to ground and their wires luckily color codes That means it was time for me to unpack the oscilloscope turn off the headlights Disconnect the battery charger and hook up decoy virus as as the ground points to the oscilloscope.
As you can see we got two not nice-looking AC sine waves which are out of phase with outer loads the headlight one features a maximum of sixty volts AC RMS While the battery charge one only goes up to half of that voltage Which is not what we want anymore In order to switch over to 12-volt system We need to replace it with a 12 volt coil, buy from online to accomplish this exchange.
We firstly removed the nuts of the magnet wheel and then used a special tool To remove it completely Next we removed the two holding brackets and pulled the back plate off According to the wiring colors we D soldered the wires from the battery charge coil unscrewed its nuts to pull it off the back plates After then inserting the new coil, we pretty much reversed all the working steps I just listed in order to restore the original state of the generator and By once again connecting the oscilloscope We can see that this time.
We got two terrible-looking sine waves Now, of course we could use the AC voltage of one coil to power the headlights and use the other coils rectified voltage in Combination with a battery charger circuit to charge the new 12 volts 9 amp hour battery We got for the mopeds But my friend wanted to replace the standard 35 watt headlights with a 55 watt one And thus he wanted to combine the power of the two coils to power the headlights and charge the battery So.
I am removing light control component Which is labeled in the wiring schematic as the battery charger circuits This component only uses an inductor to reduce the voltage at high rpms and a diode director by the AC voltage Which is truly an old-fashioned way to charge a battery but before creating our own DIY charger circuits Let’s add this full bridge rectifier will float to the two coil wires.
Like it’s shown here and let make sure ground all components Since that would partly short the coils and thus result in a terrible looking output voltage and the possible destruction of your cables In Stan’s create a separate – after the rectifier, which you can safely use for all the electrical components But anyway on the output of the rectifier we can see that the voltage is now purely DC and Since the resistors were getting quite hot as well.
This setup apparently are also the Levites sufficient energy So with this rectifier we more or less combined the power of the coils But make sure to use a full bridge which is rated for the high current flow at this point It was time for me to think about a simple battery charger and what came immediately to my mind was the lm317 Adjustable voltage regulator who stayed a sheet even features a battery charger circuits on its first page according to the voltage out and short current formulas.
I decided on a zero point 1 ohm resistor for the short current and a 172 ohm resistor and 2 kilo Ohm resistor for the voltage divider in order to achieve an output voltage of fourteen point four five volts Which should be suitable for the battery after? Building up the circuits with the dead buck soldering style I added epic dummy loads and an input voltage of around 16 to 20 volts DC which as you can see created a stable maximum output voltage of fourteen point three volts with a maximum current flow of around 1.5 amps Which is limited by the IC itself?
The only thing I forgot is that the IC you require heatsink since it is converting the excess power in two heats so after adding that I was happy with my prototype and Thus started soldering all of the required components onto a piece of perf boards and afterwards to one another according to the here shown final schematic As soon as.
the circuit was completes. I tested it once again in order to confirm that it was working properly Which it is while charging at leasts but after removing the input voltage I noticed that the bed we discharged with a current value of around seven million Which would eat to a depleted battery and only at 53 days The reason are the low value resistors on the outputs and adjust pin of the regulator Whose values I could increase but to keep it simple.
I just added a diode and Sirius to the outputs which might decrease the battery voltage a bit But keeps the battery from draining So next after securing these circuits to the mopeds lets connect wire in battery and circuit now the setup is ready Without a problem Which means this project was a success? Tidying up the wiring will be done by us on a later date, but for now, I hope that this small conversion project Inspired you to maybe fix a problem on your own Instead of relying on expensive kids.