Radio remote control has been applied in many fields because of its long transmission distance, strong anti-interference ability and directionless. However, due to the complexity of electrical appliances, huge launching equipment and difficult debugging, it has been limited in the civil field. With the development of electronic technology, these problems have been solved, which makes it have strong vitality.
Here, I would like to introduce a method of making a radio remote control transmitter and receiver.
Circuit introduction
The radio remote control transmitter is a miniature transmitter. Its transmitting frequency is 3 15MHz. When the power supply is 12V, the remote control distance is 100M, and the working current is only 4mA. A radio is a receiver and demodulator, just like a TV tuner. Its typical operating voltage is 6V, waiting current is 2mA, and receiving frequency is 3 15MHz. Using them, various radio remote control devices can be easily made, which has the advantages of miniaturization, long transmission distance, low power consumption and strong anti-interference ability. The infrared and ultrasonic transmitting and receiving heads can be easily replaced.
The circuit principle of the radio transmitter is shown in the figure. Circuit 4: emitter tube V 1 and peripheral elements C 1, C2, L 1, L2, etc. An UHF transmitting circuit with a frequency of 3 15MHz is formed and transmitted into the air through the loop antenna L2. The antenna L2 is made of silver-plated wire or enameled wire, with a diameter of 1.5mm and an antenna size of 24mm (length) X9mm (height). Transistor V 1 adopts high-frequency emitting tube BE4 14 or 2SC3355.
The circuit principle of T63 1 radio remote control receiver is shown in the figure. The receiving circuit is mainly composed of V 1, IC, etc. V 1, C7, C9, L2 and other components constitute the UHF receiving circuit, and C9 has changed its receiving frequency through fine adjustment to make it strictly align with the 265MHz transmitting frequency. When the antenna L2 receives the modulated wave, it is amplified by V 1 tuning, and then amplified by V2, and sent to IC? After further amplification and shaping, LM358 is output from the seventh pin of LM358. The actual size of the printed circuit board is 3 1mmX23CC, and the antenna size is 27mm (length) X9mm (height). OUT is the signal output terminal, and the transistor V 1 is BE4 15 or 2SC3355. The capacitor C9 can be a small adjustable capacitor. LM358 is selected as the IC.
In order to reduce the volume in the transmitting and receiving circuits, all resistors are made of 1/8W or116w. Electrolytic capacitors also use subminiature capacitors, and other capacitors use high-frequency ceramic capacitors. When welding, the component pins should be cut as short as possible to make them close to the circuit board, which should be made of high frequency circuit board.
Below are two transceivers with acoustic surfaces. Compared with the circuit introduced above, it has longer transmission distance, stronger anti-interference ability and easier manufacturing and debugging.