making 27Mhz duplicate toy car transmitter

[fever]

hello all
i bought a small remote toy car for my son.which works on 27Mhz frequency.its transmitter powred by 2AA cells.
one day he connected 9V battery directly to it(for more power),and burned the transmitter.childs play......
transmitter consists of 27Mhz crystall,and a unknown IC.when i connect power IC is getting warm.so i think IC is spoiled.
so guys is there any way to repair it or making a new 27MHz transmitter.
thanks

 

[Papabravo]

If you can't identify the IC then your chances of effecting a repair are between small and vanishingly small, unless the designer of that particular transmitter is a member of this forum. Is it an actual IC or just a blob of black epoxy on the board?

 

[fever]

its a 14pin IC.
some text is written on the IC like this--
TX-2B
YW6ADP

 

[akg]

if it is an IC, compare it with another one , if accessible

 

[philba]

I wonder how much the toy set you back? I bet it will be cheaper and a LOT faster to just buy a new one. Or do what I do with my kid when he breaks his toys by doing something dumb - nothing. it's a valuable lesson for him to learn.

 

[Hero999]

I agree don't spoil him, if you buy him a new one he'll probably break it too.

 

[HarveyH42]

I wonder how much the toy set you back? I bet it will be cheaper and a LOT faster to just buy a new one. Or do what I do with my kid when he breaks his toys by doing something dumb - nothing. it's a valuable lesson for him to learn.

He didn't say how old his son is, but in child logic it wasn't such a dumb idea. Actually, the boy may have some creative potential. Instead of RC cars, might steer him towards more educational toys.

The transmitter... well, tough to make that call. A quality RC car could use most any 27 Mhz transmitter. A small, cheap, Walmart special, would probably a bigger waste of time and money trying to build or replace. Might search the web for the part number on the chip, or Alldatasheets.com. The TX is common for Transmitter so may get lucky, but the rest looks consistent with house numbering.

For the kid, just keep an eye on what sorts of things he seem to like to tinker with, try to find something age appropriate for him to work on. He'll learn to build, and not to destroy.

 

[fever]

well he is 10.
its ture he got lot of intrest in electronics like me.in that anxity he ofen do such things.any way i'll try to fix it or else will bring another one which got low functions.so that he won't spoil them...
one more i observerd is,that TX and RX got same IC.(imean text on them is same)but TX got 14legs and RX got 16legs(in RX last 2legs 8,16 are unused)
so are they same in functioning too?

 

[HarveyH42]

It was just a guess about the TX. I don't know a lot about RC. My brother gave me a Blade CP helicopter last christmas, but need a little more room than my backyard, or just a lot of practice.

You need to find the data sheets for your chips. Since the numbers are the same, but different pin counts, likely house numbered. It's difficult not seeing what you are working on. If its a Walmart brand, just exchange it....

 

[bigkim100]

Actually...the kid uses pretty much the same logic as most adults would...making him quite smart, or at least as smart as 60% of the posters here.
His logic was...if it transmits 20 feet on 3volts...then it will work 100 feet on 9volts.
Personally, I think you should get your ass down to Wal-Mart and buy him TWO remote controlled cars. One to tear apart, and learn how they work, and one for play. Last time I was in Wally-World, they had them for as low as $9.00.
Then get your ass onto ebay and spend $6.00 on one of the old 100 in one electronic kits from radio shack. Maybe in 18 or so years, you'll have a electronics engineer on your hands.

 

[giaosucan]

I thinks you should describe more detail your IC.How many pin which it has??.How does it work ??? .Some IC which is producted by Chinese is deleted its names? I think because of license :-??
I am not sure that It is pt2272 or pt2262 ??hope that

 

[audioguru]

You won't be able to buy the IC. It is made in quantities of millions just for cheap toy RC cars.

 

[awaismqsd]

I think the the question is about R/c transmitter circuit not for the boy...
hehhe


Well fever i do a lot of work in discovering these chinese made ic's but no one know except that of Qunxing factory workers..
they usually use RX and Tx as a prefix in the ic's....better purchase a new american made toy and try to discover the logic..
best of luck

 

[HarveyH42]

Yeah, american made toys are made with destructive kids in mind... Likely use the same chips anyway...

These things weren't designed for repair, they want you to keep buying new replacements.

 

[fever]

well it is china made.
and yes it is purely for my kid only.i wana show him how things get destroyed when u won't follow the rules,and then upto what max extend we can fix them etc.
its just like a small lesson for him.i don;t expect from him to fix such complicated ckts by his own.but still in electronics if u spoil something u shld learn something.
any wany i'll try to fix it,or else buying new one is the only idea left.

 

[fever]

hello once again.
i wonder exactly which part decides the frequency of a transmitter and a receiver.the car TX/RX i saw both using 27MHz xtal,so if i change only the xtal value(say 30MHz) will this pair work at 30MHz frequency???

 

[Nigel Goodwin]

hello once again.
i wonder exactly which part decides the frequency of a transmitter and a receiver.the car TX/RX i saw both using 27MHz xtal,so if i change only the xtal value(say 30MHz) will this pair work at 30MHz frequency???

Yes, the crystal determines it, but there are usually other frequency sensitive parts as well, which may need adjusting. However, 30MHz isn't a legel frequency to do this - there are generally a small number of specific frequencies around 27MHz that you can use. The cheap 'toy' car radio systems generally aren't good enough though to use a number of channels at the same time, but 'proper' radio control model systems are.

 

[HarveyH42]

Yes, the crystal determines it, but there are usually other frequency sensitive parts as well, which may need adjusting. However, 30MHz isn't a legel frequency to do this - there are generally a small number of specific frequencies around 27MHz that you can use. The cheap 'toy' car radio systems generally aren't good enough though to use a number of channels at the same time, but 'proper' radio control model systems are.

How do you know which frequencies are legal? My helicopter is 72 Mhz, my truck is 49Mhz. Are these the same in all countries?

 

[fever]

is it only the legal issue or any othet cause.bcz i have some 4 and 5 Mhz xtals so such low frequency crystals work too

 

[Nigel Goodwin]

How do you know which frequencies are legal? My helicopter is 72 Mhz, my truck is 49Mhz. Are these the same in all countries?

It varies from country to country, the USA is particularly lax about it, and the UK particularly strict. In the USA isn't it the FCC that regulate transmissions?, presumably they will have a list of regulations?.