This is very much interesting application and I think you will surly build it. Any battery powered toy car can be made to run or stop from a remote place (around 100 mts) using this remote. Because it is RF remote you can operate your toy car through the obstacles (like wall, partitions etc.). So it will be a real wireless control for toy car.
To build this project the first thing you need is a battery (Pencil Cell) powered toy car which runs with small electric DC motor. You have to remove all its connections (with the switch or battery cells etc.) and make both the terminals of this DC motor open. The next you need is the electronic circuit that will move the toy car and a remote control.
There are two parts in this project 1) Remote control (2) Toycar circuit
Remote control circuit is same as it is in FM remote bell. Working and operation are also same. When you press switch IC567 will generate frequency of 2.75 KHz and it will be modulated by FM Tx. Circuit is shown in Circuit Diagram tab2.
Toy Car circuit:-
Just there is slight modification in receiver circuit. Here you have to rotate small DC motor in a toy car instead of generating melody sound. The idea is that whenever you press switch from remote control a DC motor will rotate and toy car will run forward. Circuit is as shown in circuit diagram tab 1.
Connection: – The main components of the circuit are IC 567(PLL), IC 555 and relay. The Signal o/p taken from FM radio is coupled to i/p of IC 567 through 100nf capacitor. The o/p of PLL is given to trigger i/p(pin no.2) IC 555. It is connected in monostable multivibrator mode. o/p of IC-555 drives relay which is connected with DC motor of toycar.
· When you press switch S from the transmitter 2.75 KHz signal is generated and it will be modulated by FM Transmitter.
· This FM modulated signal is demodulated by FM radio and given to PLL IC 567
· This IC detects 2.75 KHz signal and gives low o/p
· This low o/p triggers IC 555 and it will generate high pulse of 5 sec.
· This pulse will fires the relay and motor will get DC supply from battery.
· So motor starts rotating and toy car will run forward ( If car runs reverse then just change the terminals of DC Motor)
· After 5 sec o/p of IC-555 again becomes low and relay will be de-energized. So supply of motor is disconnected and it will stop rotating. Toy car also stops automatically.
· Pressing switch again will move the toycar forward to some distance.
So whenever you press the switch on the transmitter the toy-car will move some distance and then stops. Again you press again car will move further and so on and on. Here it is advantageous that no need of line of sight communication between remote and toy car circuit. You can run your toycar from anywhere (of course in the radius of 50 mts.) means if you are in one room and car is in other room then also you can run the car !!!!.
Filed Under: 555 Timers, Electronic Projects