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Step 4Slave Pickup and CW Generator
Ah, almost done! This step consists of adding 2 capacitors in parallel to the slave coil and connecting that up to a ladder of schottky diodes and capacitors.
Note that in the pictures below, you are looking at my heavily modified original PCB. Because of the simplicity here, this can be made on some protoboard or even dead-bug style.
The schematic and pictures really say it all, simply connect the secondary coil to the capacitors and then connect that up to the diode ladder. The 'bottom' line of the coil is selected as the ground and the top of the ladder is the output, in my case it was a bit under 5V.
The next step is simply putting it all together with some sort of storage element.
Note that in the pictures below, you are looking at my heavily modified original PCB. Because of the simplicity here, this can be made on some protoboard or even dead-bug style.
The schematic and pictures really say it all, simply connect the secondary coil to the capacitors and then connect that up to the diode ladder. The 'bottom' line of the coil is selected as the ground and the top of the ladder is the output, in my case it was a bit under 5V.
The next step is simply putting it all together with some sort of storage element.
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1.the master coil how many turns should i make?
2.the slave coil how many turns should i make?
3.the master coil is the transmitter and the slave coil is the receiver right ??????????
4.the most imp question....
will the master coil give off the 5 volts and the slave coil get that foil wirelessly????.....and in the diagram of the slave coil u showed connections for 5 volts and ground are those inputs or outputs...??????
could ya xplain the whole thing??
3. Yep
4. Nope, the master coil doesn't 'give off 5 volts', I don't know what the nominal voltage on the master is. The slave should however get pretty close to 5 volts when within a short distance.
I don't think you are understanding what's going on here. You should probably read the entire thing before starting, because you seem to be missing the point of this :). The slave coil and caps 'receive' power transferred from the master coil. The '5V' in that diagram is roughly 5 volts output, when compared to that ground point.
My secondary does actually have more turns but it has the same inductance (since it's a smaller diameter). Even if the voltage is stepped up from primary to secondary, the voltage increase isn't that much. With the CW gen, you can get a much more substantial voltage increase with a couple more parts.
If you double the number of turns in the secondary, it doesn't double the output voltage? It's different for resonant transformers?
Also you are right, this circuit has really poor regulation. That's ok as long as you don't suck down too much current, or charge a super cap like I did. It works excellently for charging large caps because it will deliver the max current possible in all situations.
The wikipedia article does a good job explaining the CW generator, but I'll try my best to simplify it. The capacitors are a temporary storage for either the positive or negative cycle of the AC source. So when you have a negative swing, the current flows through the first diode and charges the first cap to 2.5V (in our case). Then the AC source swings positive and current flows through the first cap and second diode charging the second cap to 2.5V plus the voltage stored on the first capacitor (2.5V + 2.5V = 5V). Of course this is simplified and doesn't take losses into account, but you get the general gist.
Now I picked a fairly arbitrary value, just guessed and it worked out pretty good. If you only have 1uF ones or whatever, then those will be fine. Just try to get them roughly around the same values.
Thanks for the help!