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Author Topic: Help-Remote Controlled Robot  (Read 3799 times)

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Offline combogirlTopic starter

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Help-Remote Controlled Robot
« on: August 08, 2007, 05:40:13 AM »
Guys, i have built a remote controlled remote controlled robot but the range of transmitter
is very short, It works at 29 Mhz,
Can anyone suggest me some way from which its range can be increased ? ??? ?

Offline HDL_CinC_Dragon

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Re: Help-Remote Controlled Robot
« Reply #1 on: August 08, 2007, 12:09:03 PM »
How about a little more information than that?

What receiver(RX)/transmitter(TX) are you using? Did you make the RX and TX circuits? Did you buy them pre-made? Whats there model number? How much power is going to the circuit?
these and other questions. The more we know, the more we will be able to help you ;)
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Offline combogirlTopic starter

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Re: Help-Remote Controlled Robot
« Reply #2 on: August 08, 2007, 01:12:45 PM »
Pre-made...works at 9 volt, Bought it from a friend, The receiver is fine, Robot runs with great speed.
But the transmitter its range is too short, Maximum range is 5 feet at plain ground, The signal becomes more weak if
there are obstacles... My whole project is hanging just because of that transmitter !  :-[

Offline Soeren

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Re: Help-Remote Controlled Robot
« Reply #3 on: August 08, 2007, 05:29:26 PM »
Hi,

Pre-made...works at 9 volt, Bought it from a friend, The receiver is fine, Robot runs with great speed.
But the transmitter its range is too short, Maximum range is 5 feet at plain ground,
Sounds like your robot is either very electrically noisy, swamping the transmissions, or an embarrasing oops have set in... Nah, you did check the 9V battery for power, right?  ;)

Quote
My whole project is hanging just because of that transmitter !  :-[
I'm very curious about how you descide that "the receiver is fine" and "the transmitters range is too short"?
(Since, somehow I don't think you know the transmitters ERP and the receivers sensitivity and range is what those two numbers achieve together).

To boost range:
Check voltage of 9V battery during a transmission.
Reduce EMI from robot (probably the main culpritt).
Enlarge antennas on both TX and RX, unless they're wavelength calculated.
Make a 1 transistor antenna amplifier for the receiver.

I assume the 2 parts come from an R/C-vehicle and if so, range must have been a tiny bit better 'till you installed it in your 'bot.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline combogirlTopic starter

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Re: Help-Remote Controlled Robot
« Reply #4 on: August 09, 2007, 08:04:58 AM »
The receiver is fine because when i move near to robot it moves fine with great speed  :-X

Make a 1 transistor antenna amplifier for the receiver. How to do that ?  ???

Offline Soeren

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Re: Help-Remote Controlled Robot
« Reply #5 on: August 09, 2007, 04:44:25 PM »
The receiver is fine because when i move near to robot it moves fine with great speed  :-X
Perhaps it's just your presence getting the robot to behave ;)

Seriously... You have to understand that it might as well be, actually it more likely is, the receiver that's being swamped by noise, when the transmitter signal weakens a bit.

Quote
Make a 1 transistor antenna amplifier for the receiver. How to do that ?  ???
I'll tell you as soon as you have verified the points mentioned before this on the list - I listed them in the sequence they should be carried out. Making an antenna booster will only worsen things, if the other points are not dealt with beforehand.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline Admin

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Re: Help-Remote Controlled Robot
« Reply #6 on: August 09, 2007, 05:56:59 PM »
29Mhz? There are many RC toys that use 27Mhz . . . So I suspect you have a 'made in china' style remote? They inherently suck, but you might be able to mod it . . .

The easiest way is what Soeren mentioned, which is to use a single transistor to amplify the signal. Read up on how transistors work (wikipedia, google).

Read the first few links on this page:
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=DGUS,DGUS:2006-11,DGUS:en&q=transistor+amplifier

Im definitely no RC expert, far from it . . . but you can also use op-amps as well.
http://www.societyofrobots.com/schematics_voltamp.shtml
http://en.wikipedia.org/wiki/Op-amp

op-amps are a bit confusing at first, but they are actually very simple to use. Same with transistors.

The easiest solution . . . try increasing your antenna length. Solder a really long wire to your antenna . . . its ugly, but it just might work . . .

Another solution. Transmission for RC is best when both antennas are parallel. Hold your remote parallel with your robot antenna and that should help, too . . . (a cheap ugly trick, I know . . .)

Offline combogirlTopic starter

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Re: Help-Remote Controlled Robot
« Reply #7 on: August 11, 2007, 07:58:29 AM »
Soeren, Thanks for your interest, I checked all you mentioned

Check voltage of 9V battery during a transmission.)
Took a new battery, Also ran it with an adapter, range didn't increase a centimeter   :(

Reduce EMI from robot. (How can i do that ?)
Enlarge antennas on both TX and RX, unless they're wavelength calculated. (antennae is already long)

The admin's tip to solder a wire to the transmitter did work though but i can't walk around with a large wire dangling around me..
I think the only solution to my problem is to make that 1 transistor antenna amplifier, How can i make it ?  ???

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Re: Help-Remote Controlled Robot
« Reply #8 on: August 11, 2007, 08:05:43 AM »
Quote
I think the only solution to my problem is to make that 1 transistor antenna amplifier, How can i make it ?
hmmmmm the schematics and instructions are listed in my last post :P
If you are stuck somewhere just let me know what you have already . . .

 


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