Circuit Project Electronic

The Witness Camera operation is conceptually simple, but involves many ingredients. Some are physical components, the others are software blocks. To make things clear, I will introduce them gradually, according to the operating mode.

The most important hardware component is the ITC328 camera module. It consists of a VGA (640×480) CMOS colour sensor and a JPEG-compression chip. The compression engine includes a serial interface at 3.3V levels that can be connected directly to a microcontroller’s UART. Issuing the appropriate commands you can take snapshots as JPEG-compressed byte streams. The camera comes in a handy module with everything including the lens, and a 4-pole connector for power and data.
The most important software component is the AVR-DOS file system. It is a library for driving mass storage devices, like SD and MMC cards, CompactFlash, and even hard disks connected to the AVR microcontroller. It provides an high-level programming interface for accessing disks formatted according to FAT16 or FAT32 specifications, which means its files are directly compatible with PCs. By linking AVR-DOS to your program you can create and open files, write and read data, create and change directories with simple commands, like you would do on a PC. Restricting read/write access to one file at a time, the FLASH and RAM footprints are minimal (8kB and 1.3kB), making it possible to use a small 8-bit AVR device like the Mega32 for tasks usually accomplished by 16- or even 32-bit processors.

These two blocks are the foundation and starting point of the Witness Camera design. With the aid of the simplified block diagram of Figure 1, let’s see how these block interoperate during normal operation as a time-lapse recorder.[...]

Read More Source:
http://www.electronicsweekly.com/blogs/gadget-freak/2008/05/
keep-your-property-where-you-c.html

This is PWM Speed DC motor Rotation circuit. It can Forard-Reverse and Regenerative Braking function. By this circuit use a signal PWM control the speed of DC 12V motor with Power mosfet IRF150. The relay RY1 use control Reverse with the digital alarm , change , Q10. The Relay RY2 work be , function brake resistor. By control Run or stop with the digital alarm with . The F1 , use protect through the circuit. The D1 use for protect current turn back from DC Motor. The detail is other , please see in the circuit.

The compact 5 pin L165 IC general a stabilized symmetrical power supply from a single asymmetrical power supply. The output voltage is however, half of the input voltage. One needs to add the ripple filter capacitors C1, C2, C3 and C4 and some resistors for setting the symmetry. In constructing the circuit, place the capacitors C1 and C2 as close to the IC as possible.
On the other hand, place the capacitors C3 and C4 close to the output jacks. Make sure that the circuit lines on the pcb are properly dimensioned to handle high current levels. Current levels up to 3 amperes can flow through the circuit. Additionally, provide a proper heatsink for the L165 IC.
The L165 IC can also be viewed as a voltage amplifier. It amplifies the voltage appearing at the junction between R1 and R2.
One cas also replace the IC with TCA1365. However, when using the TCA IC, pins 3 and 4 have to be connected together. Also connect a 220pF capacitor between pins 5 and 6.

Link : http://apowersupply.com