Small RF universal remote controls


This small Radio Control (RC) circuit is easliy. It can install with a toy train or automobile that used a voltage supply from 6-12 volts. Which the radio receivers sectors is installed in the car will turn on – off the DC motor runs by forcing the rhythm on – off of the transmitter radioInstead of using a switch turns on-off in the car.

The principle of circuit on the radio receiver section.
The circuit in Figure 1. is simply a receiver and controller. By the high frequency receiver that is in a Q1(2SC828 or 2SC458) act received the radio frequencies. In rang 270-300 MHz. There is a trimmer -VC1 is determiner a value of frequency receiver in conjunction with, L1 Is high-frequency coil.

Receiver of small rf universal remote controls

Figure 1.

So if adjusted Trimmer will make receive frequency changes according to the value as above. Radio frequencies that incoming is converted into a low power audio signal. So need to use Q2, Q3(2SC828 or 2SC458) acts amplifiers from The circuit in part of Q1. To lead the sound, From the transmission sector incoming through power amplifiers. Which is to receive audio through the expansion From Q2, Q3 through C10. To the base of Q4(2SC1061 or TIP41) To conduct current through R11 to control the Q5. Which is transistor drive the DC motor rotate and LED1 flashes with the beat. Delivery – receive signals from the transmitter. They will be able to control or stop the car as needed.

The principle of circuit on the radio transmitter section.
The circuit in Figure 2 is the transmitter circuit with a simple principle. Operation just like The radio transmitters or a normal wireless microphone circuits. By Q1(2SC828 or 2SC458) acts as high frequency radio generator. It can Change the the transmited frequency output by changing adjusted VC or a trimmer in there.

Transmitter of small rf universal remote controls

Figure 2

Specific radio transmission to the receiver can not work. So must have a tone generator circuits. With Q2, Q3 In conjunction with C2, C3, R3, R4 and R5. Created tone frequency is mixed with the radio broadcast of Q1 and then sent to the receiver. To control motor and LED contacts.

Pcb layout of the transmitter circuit

Figure 3 is the PCB layout of the transmitter circuit

Pcb layout of the receiter circuit

Figure 4 is the PCB of the receiver circuit

How to builds
On Figure 3 is the PCB layout of the transmitter circuit. And Figure 4 is the PCB of the receiver circuit. Details about soldering equipment. I do not say again Because There are several articles already, Friends certainly would not like to read.


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