Circuit for prepaid energy meter

The above designed circuit represents a prepaid energy meter. This circuit uses the Atmel IC 8052 i.e. AT89S52 an 8-bit microcontroller IC.AT89S52 is a low voltage, high performance CMOS 8-bit microcontroller with 8K bytes of In-System programmable (ISP) flash memory and a three level program memory lock. It has operating range from 4.0V to 5.5V. AT89S52 is also equipped within by a 256X8-bit internal RAM and three 16-bit counters. Also, the IC ULN2003 used is a high voltage, high current Darlington array containing seven open collector Darlington pairs with common emitters. Each channel is rated at 500 mA and can withstand peak currents of 600 mA. In it suppression diodes are integrated for inductive load driving and the inputs are pinned opposite the outputs to simplify board layout. The IC used AT24C02 is a two-wire serial EEPROM. It provides 2048 bits of electrically erasable and programmable read only memory organized as 256 words of 8 bits each. It is very useful in applications where low-power and low-voltage operation are essential.

Circuit for fingerprint security system

This is the circuit designed as a hobby project. Here, a fingerprint module has been automated to create an automated fingerprint security system. This circuit uses the Atmel IC 2051 i.e. AT89C2051 an 8-bit microcontroller IC.AT89C2051 is a low voltage, high performance CMOS 8-bit microcomputer with 2K bytes of flash programmable and erasable read-only memory (PEROM).It has operating range from 2.7V to 6V. AT89C2051 is also equipped within by a 128x8-bit internal RAM and two 16-bit counters. Also, general purpose switching and amplification transistors BC547 have been used in the circuit.

Circuit for home security- page 1

The above designed circuit represents an automated home security system. This is the first part; sensor circuit has been described in the latter post below. This circuit uses the Atmel IC 8052 i.e. AT89C52 an 8-bit microcomputer IC.AT89C52 is a low power, high performance CMOS 8-bit microcontroller with 8K bytes of Flash Programmable and erasable read only memory (PEROM) i.e. In-System reprogrammable (ISP) flash memory and a three level program memory lock. AT89C52 is also equipped within by a 256X8-bit internal RAM and three 16-bit counters.

Circuit for Home security (contd.) - touch sensor

The above designed circuit represents an automated home security system-sensor circuit. This is the second part for the above post.It describes the design of the touch sensors required to gather input for the above posted circuit i.e. the circuit for home security system.