Im trying to build this circuit and it basically says to build your own inductor using 0.3mm enamelled copper wire wrapped 7 times around a ferrite core. Does the inductor have to be this way? Or can i get away with using a different one that i dont have to make myself. Link Below:

http://www.circuitstoday.com/5-channel-radio-remote-control

 

Until you have a working prototype I suggest you build it as designed. Once you have a working unit you can experiment with variations and modify the design. I'm assuming you do not have the test equipment budget or the RF engineering expertise to design and troubleshoot such a design from scratch.

 

Until you have a working prototype I suggest you build it as designed. Once you have a working unit you can experiment with variations and modify the design. I'm assuming you do not have the test equipment budget or the RF engineering expertise to design and troubleshoot such a design from scratch.

You're right, I really don't have any experience. Do you know of any place where I could get those sizes of enameled wire? I've been searching online but can't really find a good place to get it.

 

You're right, I really don't have any experience. Do you know of any place where I could get those sizes of enameled wire? I've been searching online but can't really find a good place to get it.

I always try Digi-Key first. You don't say where you are located so that may not be a helpful suggestion.

 

I always try Digi-Key first. You don't say where you are located so that may not be a helpful suggestion.

I'm from a small town in Idaho. I went to the website for Digi-Key and they have tons of stuff. I'm just not really sure what I'm looking for.

 

That's not too far from Thief River Falls. The common name for what you need is magnet wire.

http://www.digikey.com/product-search/en/magnetics-transformer-inductor-components/magnet-wire/5113147?k=Magnet Wire

You'll have to figure out which wire guage to select and how much to buy.
Yikes a spool has way more than you need.
Next suggestion is to find a local ham who will cut a piece for you.

 

Or you could unwind a few turns from a scrap transformer or motor.

Edit: If you don't have exactly the same ferrite as the type the circuit designer used then the wire gauge is somewhat academic. A gauge approximating 0.3mm diam will probably be ok.

 

If you go to the Coilcraft site they will send you a couple of samples out F.O.C. http://www.coilcraft.com/
I just got a couple sent out in the last week or so.
Max.

 

If that is 3mm dia that would be around 38awg, which you may get that off of a miniature relay if you have any, I suspect the gauge is not critical, within reason.
Max.

 

I'm actually still in highschool and have always wanted to build an rc car as a project. I've built a few audio amps in the past and I've just been learning as I go. In this circuit, the interface with the relay is there so that I can run a higher voltage to a motor or whatever and it's just controlled by the recurve right?

 

*receiver

 

RadioShack sells a pack of magnet wire with 3 different sizes... you may want to check your local store first...

 

In this circuit, the interface with the relay is there so that I can run a higher voltage to a motor or whatever and it's just controlled by the recurve right?

You could also interface directly using a Mosfet at the O/Px and eliminate the relay.
Or a 2n7000 for the relay operator if needed.
Max.

 

You could also interface directly using a Mosfet at the O/Px and eliminate the relay.
Or a 2n7000 for the relay operator if needed.
Max.

Here's another question. The interfacing relay is using a 2n2222 transistor. They are only rated for 900mA. I'm worried that if I run a higher amperage through it it will burn up. Would either of those ways handle higher amperage? Or is there a different transistor I could use that will work the same but is rated for a higher amperage?

 

Max,
I did some reading, and correct me if I'm wrong, but I think a MOFSET would be the best way of going to handle higher amperage. But I also read that to do that and run higher amperage I would have to change the base amperage. Is that true? It would probably need to run around 6 amps.

 

The gate of a Mosfet requires a voltage as opposed to a bi-polar 2n2222 which requires base current.
IOW it does not impose the same load on the source using a Mosfet.
The IRL520/530 offers higher current capacity.
Max.

 

So would I be able to just substitute an IRL530 for the 2n2222 to control the 12v motor? What else would I have to change in the interfacing relay circuit?

 

I couldn't find the spec sheet on the RX to find the exact nature of the output, but normally a straight substitute to the Mosfet is that easy.
You could take a 100k resistor from gate to common.
The only thing about controlling a RC motor this way, it is either on or off, no speed control.
Max.

 

So I could just keep the relay and everything and substitute the transistor for the MOSFET?

 

Here's the data sheet for the rxb2