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

This be 8A Solinoid coil driver circuit. Which use mosfet number IRF150 2 amounts, be important equipment , it performs to drive Solinoid coil. Which be valuable low resistance, use current the plentiful. By use the way encourages of input model PWM make use current , share lower, mosfet not very hot. Unless R16 still use fine but current adjust and R15 use fine decorate Release Adj as well .
(PWM duty cycle) D = Vout/Vin , want about 3V, D = 3/12 = 0.25 etc. , want about 9V, D = 9/12 = 0.75. The R16 take keep fine topmost trend has depend upon a kind of solenoid.
The R16 , can fine get from 4A trends arrive at 9A. The D1 help cover up something current flow turn back from solenoid coil. The C1 use increase efficiency of the circuit. The detail is other, please see in the circuit.

This simple 220V power interface is intended as an interface for monitoring electric equipments and devices using a computer. The interface only senses whether the device being monitored is turned on or off. The most important aspect of the circuit is the galvanic isolation between the AC main line being monitored and the interface to the computer. This is done with the use of the optocoupler IC TIL111 but a suitable replacement can be used too.

Useful for electronics hobbyists, this linear workbench desktop power supply circuit converts a high input voltage (12V) from the SMPS of a PC into low output voltage (1.25 to 9 volts). An adjustable three-pin voltage regulator chip LM317T (IC1) is used here to provide the required voltages. The LM317T regulator, in TO-220 pack, can handle current of up to 1 amp in practice.

The diagram shows the circuit of the desktop power supply. Regulator IC LM317T is arranged in its standard application. Diode D1 guards against polarity reversal and capacitor C1 is an additional buffer. The green LED (LED1) indicates the status of the power input. Diode D2 prevents the output voltage from rising above the input voltage when a capacitive or inductive load is connected at the output. Similarly, capacitor C3 suppresses any residual ripple.

Connect a standard digital voltmeter in parallel with the output leads to accurately set the desired voltage with the help of variable resistor VR1. You can also use your digital multimeter if the digital voltmeter is not available. Switch on S1 and set the required voltage through preset VR1 and read it on the digital voltmeter. Now the power supply is ready for use.

Read more Source:
http://apowersupply.com/desktop-power-supply-circuit-34.html

This be power motor controller 12V circuit. with a signal MCU Control be high class voltage , about 3V. It can motor control turn advance or walk go backwards all right. By use power mosfet number IRF150 use apply to 100W small stump size hills. The relay 12V 2 contract , for change electronic pole gives motor. By feed a signal Reverse Rotation change a B pins of 2N3904 give it works to give the electric current to the coil relay. This circuit uses voltage 12V at current about 10A. The C1-4700uF help increase efficiency of the circuit while , feed the fire gives motor during first. The D2 use protect the electric current pulls sharply from motor harm with mosfet Q1-IRF150 get. Other detail in the circuit.

This AC to DC converter circuit is capable to convert an alternative voltage from 70 – 260 Vac into a DC voltage from 180 to 250 Vdc.
To achieve this convertion we use a rectifier MC34161 as a voltage doubler at low input voltages and as a classic rectifier at high input voltages.
MC34161 includes a reference power supply which delivers 2.54V at pin 1. The signal level applied at pin 2 is internally compared with a 1.27V voltage.
D5 zener diode, togheter with R1 and C4 provide IC’s required 12V voltage. Capacitor’s voltage of C2 and C3 must be > 250V. [...]
Read more Source:
http://apowersupply.com/ac-dc-converter-circuit-263.html

Here is a simple and effective circuit for driving florescent lamps from a 12 V supply.The circuit is nothing but consists of an oscillator, a MOSFET switch and a step-up transformer for driving the florescent lamp.

The IC1 TLC 555 is wired as an astable multivibrator for producing the necessary oscillations.The MOSFET Q1 is used to amplify the oscillations produced by the IC1.The out put of MOSFET is connected to the primary of the step up transformer to produce a ~400 V AC for driving the florescent lamp.

Read more :http://www.circuitstoday.com/12-v-florescent-lamp-driver-circuit
Thank you

This is circuit Automatic Charger and Full charged indicator. For 24V batteries it can charger with current be stable about 1.5A and have voltage output 27Volt with integrated number circuit LM317K. When the battery has had full already , as a result will cut the work. There is a tube LED show the work with use integrated number circuit LT431 perform check the level , voltage battery and systematically protect short circuit with IC LM317. Unless D2 perform protect wasp a pole battery wrong as well. The IC1 should hold heat sink with. The detail is other , see in the circuit.