what would happen if I replaced the 5K pots used for the rudder and elevators with a single 10K pot joystick like this one:-
http://parts.digikey.com/1/parts/745222-pot-joystick-10k-ohm-252a103b60na.html
would it affect the controls in any way?
since using a joystick is better than using a pot...

Rajiv, before altering the POT, please make sure, this will not hurt the radio circuits.. and result will be fascinating, and funny, if you do it with care and self research..

Look,
All this POT movement works with time constant of R-C circuit, the time constant.

Now if you have no alternatives, just replace the 5K with 10K, but simultaniously have to replace the timer capacitor value so that time constant remain the same.

Again, the change of the resistance will disturb some biasing value of the transistor and you have to modify them too.

any idea what those replacements are?
the main reason for changing two of the 5K pots to 10K joystick is that it is easier to control the plane using a joystick how ever the 5k joystick is a lot costlier than the 10K one hence planing on using the 10K joysticks

Quick review gives the idea. Have to be severally cross checked with Thevinin.
Here is the simple idea is modify parallel biasing resistance.
As they are available.

look, 5K ║ (2k2 + 2k2) ≡ 2.34kΩ

and  10k ║ (1k5 + 1k5) ≡ 2.307 kΩ and similar.

So, just replace 2.2 kΩ with 1.5 kΩ and watch the waveform.

Now cross checking to be done with input side and output side behaviour (Resistance range) or value variation.

that means i will be replacing R10, R11 , R14, R15 to 1.5kΩ (these are the 2.2kΩ resistors corresponding to the rudder and elevators) right?

Hi,

I have assembled the encoder and decoder, and it is working fine when i connect the o/p of encoder with the i/p of decoder.
Kindly help me how to connect the wireless interface and what precaution to be taken, if I am using 434Mhz tr/rx module for a short range.

Thanx,
Dayanand

Oh, superb, Can you post some pics/video please ? You are really valuable to us as your 2nd post is about success.
http://forum.keirle.com/index.php?topic=14.msg58;topicseen#msg58

Pls find attached the encoder and decoder snaps.
Actually I am making a home made heli.
For the same i wanted to interface these enc/dec unit thru standard 434Mhz tx/rx so that it can work for at least for some meters.
Thanx for giving the link for tx/rx, but actually due to lack of time, I want to use this low cost module.
Pls. give suggestions.

Thanx...

Good evening members.....

Are there any problems in using fm rx/tx and with encoder and decoder. If so, an fm transmitter with a range of 2kms means a good radio control system.   

can anyone sell me a rx and a tx

I would not recommend FM trans / rec as there will be lot of interference due to signals in air. Normally the freq range of FM is upto 108Mhz and I do not feel that up to this length it will work smoothly w/o interference.
As the encoder is sending simple pulses of 1ms to 2ms and if there is no error correction in such tx and rx, you will keep struggling with noise and since we are using it on a flying object, I am sure you will crash it on first run.
I will share my experience using 433mhz module available at low cost in market. I have connected these enc / dec thru this module.
-One problem is the position of tx and rx matters a lot, even at a distance of 3-4mts.

-second issue I am struggling with is the interference EMI noise produced by brushed tail motor which I have installed in my home made heli.
There is so much radiation from brushed motor that even if I use a separate battery to run the motor with three filter capacitors of 0.1uf and after grounding the motor body, that the mail brush less motor starts running with transmitter being switched ON.   

The motor noise disturbs Am Modules performance.
You need ferrite bead in adition with capacitor. But better use FM Transmitter and receiver circuit. Just use BF494B made transmitter and similar RF buffer with anttna tuning  PI circuit to maximize output.
And in receiver side use superregenerative one or any IC based circuit. Tuning is a crucial parameter here. You should use wax in coils to avoid detuning.

You may try xbee pro modules, but I cannot help. Perhaps VKSingh or Sultan may help.

Thanks

I will try with FM tx/rx.
Request if you can suggest any good circuit for this purpose.

You can check the link in the mother site.
http://forum.keirle.com/index.php?PHPSESSID=d999c9a158cc118425c14651d324b9b5&topic=14.msg54;topicseen#msg54


I still waiting for PI/ladder network circuit analysis from design and realization point of view, Some of parameters are configned within working zone brilliantly. You can use a tiny speaker in receiver side (before entering into decoder) with a small amplifier and tuning FM Gang in Transmitter section initially. Later you can select Trimmer Capacitor.

Have you gone all the links given previously and only one stage deeper ?
http://myweb.tiscali.co.uk/norcimradiocontrol/Radio9a.htm

Hope it will work.

winding a cd drive motor thanks for the diagram

I have assembled a FM transmitter with 35mhz crystal. Working on increasing the range.
My KDS800 gyro which I purchased, was either faulty or I destroyed its controller, frankly I do not know.
But rather than throwing it out and going for a new one, I traced out the analog o/p of the sensor module and used a differential amplifier with LM324 and a mosfet at output to control the speed of small DC tail motor with a carbon fiber 6X4 propeller.
It is working almost well as a controller with fixed pitch blade can work.

To check this, I have made a platform mounted on a bearing to leave it free to rotate and tied the heli with platform, with main blade angle at ZERO degree so that it may not lift up.
I am trying to upload video soon...

any member pls. guide me how I can upload .mov or any other format video.

Hi,
Recently Bilal requested for an easy reversible ESC used in other purpose, but controlled by Tx/Rx.
So, the communication protocol with Rx to ESC should be with pulse width duration control.
As Bilal is not an electronics background guy, micro-controller based circuit is useless to him except analog one. So, I searched for proven circuit (As I can make trial and error, but he cannot, or you can say I should not impose him for R&D). So found this.
http://www.pt-boat.com/electric/speedcontroller.html
http://www.pt-boat.com/electric/images/speedcontroller3.gif

And the wave-shape controlled picture is also with this. Now LM358 may be replaced with LM324 (quad Op-Amp).

The optional test oscillator is nothing but the test circuit or servo tester.
Hope this will be beneficial to all and specially car and boat lovers.

Thanks

Is not this circuit a bit too much for a electronics noob like Bilal or myself ? More over from what I make out, it needs two batteries

exactly my point Lastrites
and Kalyan sir, in the second link that you have posted, can i connect same battery at both  battery terminals and reversing battery terminal by just swapping the battey wires?......that would save me some bucks

am attaching a pic if that helps

Dear Bilal, do you know any shop where we can get Depron sheets in lucknow.

1-2 yers back i also tried the same , successfully made the tx , checked with oscilloscope all gud , but messed up with the receiver part , ultimately gave up the project.
i still may have the tx part , if any one intrested , will give it for free [will try to search my house if i get it].

thanks for the reply


    can we use the RC transmitter set on different frequency i mean 2.4 MHz ,2.6, 2.7 or set it to send signals to any receiver of
same frequency 

Hallo everyone, I'm new here
Can anyone please reupload the encoder and decoder from kaylan first post from www.pm.keirle.com
the site no longer exist.

I have built an encoder actually, using ic 4017 but why the signal amplitude just about 40 mV, and the off periode between pulse from the encoder was hard to adjust even I have high value pot, Thanks

Please PM me your e-mail ID so that I can send you the resources as they are saved as PDF for offline study.
And also other resources of discrete circuit if you are interested.

With digital voltmeter, in AC or DC mode you cannot measure the voltage as they are pulses and before the stable measurement, the pulse voltage become zero. So you need osciloscope to measure [or have to connect (in fact just touch the leads makes parallel) an extra capacitor of 1000 times that make the pulse from milliseconds to seconds if the circuit have the option.]djusting is little bit difficult as the resolution becomes large and your arena becomes so small.
What would be easier to you ?
a) Adjust 5.6 KOhm using an 5K and 1K POT in series, ......................[Min=5 KOhm and Max = 6 KOhm]
b) Adjust 5.6KOhm using only 10K POT.............................................[Min = 0 and Max = 10 KOhm]
c) Adjust 5.6KOhm using an 100K POT..............................................[Min = 0 and Max = 100 KOhm]
Hope I can express as simple as I can.

With high value pot, adjustment resolution becomes high and you can get lower accuracy.

Thanks