My Light Diagram

Circuit Diagram Description The door latch alarm circuits are simple and effective and easy to construct. Normally the alarm is in de-activated mode by keeping the switch s1 in off state which can be done with a lock and key kind of switch. Number of doors can be guarded against the intrusion by keeping or connecting the reed switch in series fitted with the help of a magnet. The reed switch can be fitted in such an way that the magnet is fixed on the door, in normal conditions when the door is closed reed switch will be held close to the magnet and hence the reed switch is kept closed , when the door is opened the reed switch contact is opened , this triggers an SCR, the gate of an SCR is connected to its cathode through the reed switch as long as the switch is closed the SCR dose not fire but when the door is opened the SCR is fired supplying an voltage to the alarm circuit. Source -http://www.electronguide.com/circuits_pages/DoorLatchAlertSystem.html

Consider a situation where a burglar has entered your house and snapped the telephone wires, leaving you with no means of communication with the outside world. In such an emergency, you will find this intruder alarm to be very handy. It transmits a prerecorded emergency message repeatedly for reception by an FM receiver. The message containing address, geographical location, name, etc is recorded onto a chip. The prerecorded message can then be transmitted repeatedly with the help of an FM transmitter, in the hope that some noble soul will hear it and inform the police about the incident.   Fig. 1: Block diagram of the intruder radio alert system The circuit comprises a sound recording-and-playback chip (UM5506BH). This chip consists of a 96kbit SRAM and can record up to six seconds of audio. (For details, refer ‘Mini Voice Processor’ circuit published in April 2000 issue of EFY.) After the required message has been recorded, it is passed to a low-power, VHF FM transmitter wired ar...