4ch rc schematic help

[Sengo]

Hey everyone,

I found this schematic a long time ago and always wanted to build a few radios for micro airplanes and such. The only problem is that I don't really know much about it. When I read the material that went along with it my hopes of building it were dashed when he said he left some of the design aspects up to the individual reading it.

Can anyone here help me complete the circuit so it is usable?

I hope this document will be viewable because I think its really amazing if it can be made to work.

Thanks,

Sengo

MINIATURE_RC.pdf

 

[audioguru2]

The most important part of that very old article is missing, its modulation. Its old radio ICs might not be available anymore.

I went to a meeting of a model airplane club. They had tiny planes that were controlled by the motor, electronics and controllers from a $10.00 micro RC car. The planes can climb with the motor at full speed or glide with the motor off. Reverse isn't used. Go straight, turn left or turn right. I can't remember where the tiny Li-Po battery comes from.

 

[Sengo]

Hello audioguru,

I have seen some of those planes as well. The only reason I was hoping someone would be able to help me with this one is because it has four channels and (I think) the frequency can be changed so you can have numerous radios functioning in a small area.

I'm sad to hear that it's missing important information, but I guess thats life. Oh well, onto my next project

Thanks again,

Sengo

 

[audioguru2]

Hi Sengo,
The cheap RC micro cars use 27MHz and 49MHz so two can be used at the same time.
The "servos" are just a small coil of wire around a small magnet and are just on and off.
These tiny planes must be lightweight or they fly like a brick (won't fly).

A guy on the web is selling a micro helicopter. Many of its parts are expensive, strong and lightweight carbon-fiber. Its video shows how tiny it is when it takes off and lands on his hand.

 

[Sengo]

Sorry to bring this up again, but I may have found a correct schematic for those micro recievers you are talking about. It even seems to explain how the frequency can be changed by swapping out a particular resistor in the oscilator (spelling?)

I may be wrong, but I think with this data sheet it would be possible to build some hobby radios with a wide variety of frequencies. It is also possible that it is missing some important information as I am not quite an electronics wiz.

Nick

tx2c_and_rx2c_data_sheet.pdf

 

[audioguru2]

Go to Taiwan and buy a few thousand of those cheap toy transmitters and receivers. The datasheet shows them in a toy car and they control bang to the left, bang to the right or straight. You steer by banging. It also has  reverse and  turbo "quickly kill the battery" functions.

They have a separate 27.145 MHz radio transmitter oscillator and a cheap super-regen receiver.
The resistor changes their clock frequency so their infrared frequency can be different than your TV remote.

Have fun banging along.

 

[Sengo]

So changing that resistor value doesn't mean you can have dozens of them running around?

 

[audioguru2]

So changing that resistor value doesn't mean you can have dozens of them running around?

No. The resistor controls the infrared frequency. You would have a difficult time controlling something that moves with infrared. Your TV remote uses infrared.

The radio is a completely separate circuit and the receiver is so cheap that only a few would be able to run around together.

Model radio controlled airplanes use a radio system much more complicated and more expensive than this cheap one and can have about 10 of them running around together.

 

[Sengo]

Okay, now I understand. Thanks.