Dilshan R Jayakody’s Web Log

This project is about a wireless musical call bell, which I designed to meet some of my friend's requirements. This circuit design uses only the 4000 series CMOS logical ICs, NE555 , UM66 , and TDA7233 audio amplifier IC. For the remote control, we use a 433MHz 4-channel remote control module . This circuit is designed to work continuously with a low-power external 5V power supply. Prototype version of wireless call bell. The PCB in this call bell is designed as a single-sided PCB. The dimension of the PCB is 82mm × 50mm.  All the components in this circuit are commonly available through-hole-type components. The whole assembly process of this musical call bell is shown in the video attached to this document. The RF remote control module we use in this project consists of a remote control decoder and encoding IC. In our version, the transmitter (key fob) has a PT2262 encoder, and the receiver has a PT2272 decoder IC. In the prototype build, the receiver and transmitter are confi...

After the 2 weeks of continues development we finally design suitable RC remote control system for cars. This RC system has, Battery eliminator circuit (BEC) Control System 433MHz transmitter and receiver module Motor driver and servo controller In this design both transmitter and receiver modules are based on seeed studio’s 433MHz RF link kit and control systems are based on microchip’s PIC16F84A MCU. At the design time we test this circuit with Futaba, Airtronics, JR-Radios, HiTec and "Mystery" (available in eBay) micro-servo units. This circuit may support standard electric motors (brushed DC motors) and during the testing stages we drive RC helicopter motors and RC airplane motors successfully with this system. To drive this circuit we use 7.2V 500mAh Li-Po batter pack. During the circuit assembling and testing, make sure to take necessary actions (e.g: shielding) to prevent/minimize the EM interferences which was generated by the motors. Most of the time t...