The purpose of electronic circuits is to control the flow of electric currents. This may sound like a silly question, but why do we need to control the currents? Well, it has been found experimentally that the intensity of various electrical effects is related to the amount of the charge Q that passes by a certain region per unit time.

Burglar alarm system is an important part of home security systems. This burglar alarm project is based on PIR sensor, UM3561 and Speaker. PIR sensor used to detect body motion and UM3561 & speaker to produce Police siren after any movement detection.

We are very much familiar with our television sets, DVDs, MP3 players, music systems and many other device that are controlled by using IR Remote. There are many types of remote controls available for different devices but most of them work on around 38KHz Frequency signal.

Blue - negative, ground Red - positive, Vcc Brown - 74163 pin 11 (Output A) Green - 74163 pin 12 (Output B) Magenta - 74163 pin 13 (Output C) Gray - inverter output

If an oscillator of a particular frequency and mark to space ratio is required, the method would be to calculate periodic time from the required frequency and the discharge time and charge time using the formulae for tD and tC described in Oscillators Module 4.3. To do this, some component details will be needed.