Need help modifying rc car circuit

[trip6]

Hello,

I have this old toy RC car and a pager and I am wondering if a small hack, using the two is possible or not. The pager doesn't work but its motor does. I want to make a new "pager" that vibrates when the car's remote is used. The car has a small reciever circuit (27MHz if that's of any use) connected up to its own motor and uses 4x1.5V AA batteries. Its remote(transmitter) uses a 9V battery.

I would like to make this as small as possible (matchbox size preferably so it fits easily in a pocket). The reciever circuit is pretty small, its the motor that it is connected too, and the 4 batteries that take up a lot of space. Since I have this pager motor lying around I though it would make an ideal replacement for the car motor...greatly reducing the size.

And that's as far as I my limited knowledge of circuits takes me :)
Is there a way to determine if I can reduce the number of batteries(and hence the space) for the modified circuit? Will reducing the batteries effect the reciever? Also that pager motor is much much smaller than the car motor. Do I risk burning it up? And lastly the antenna is about 7-8inches. Can I bend it to reduce the size?
Sorry for all the dumb questions(hopefully not posting in the wrong forum) but any help would be greatly appreciated. Thanks a lot.

 

[SystemTheory]

Most older RC receivers need more than 4.5 volts to operate as far as I know. It may be hard to eliminate voltage cells on the receiver. A step up switching power supply is a solution but hard to build yourself and probably costly to purchase. You might try to google for Rx hack that works on low voltage, such as wireless mouse or something like that, usually with much less Tx/Rx range.

Edit: afterthought, you might check the RC boards for more info on hacking old RC equipment.

 

[trip6]

Thanks for your reply. I was hoping it would work over larger distance 25-30 meters (similar to range of keyless entry of cars). If this can work, its for someone who has recently lost their hearing. There are all kinds of alerting and signaling systems available for the hearing impaired. They seem simple enough but the prices just seem crazy.

I'll try to find some RC boards to post on. I saw some lithium camera (3V) batteries on sale which take up much less space than 4AA's. I might give those a try too. Thanks again for your help.

 

[SystemTheory]

google key fob reciever. There may be an economical solution already available.

http://www.homesecuritystore.com/c-121-keyfobs.aspx

Good luck!