LM317T Voltage Regulator with Pass Transistor

This PIC-based project plays converted .MOD chiptunes. The circuit consists of a PIC18F2685 (chosen only for its large program memory--I could have just as easily used a smaller PIC and an external EEPROM), a DAC, and an LM386 linear op-amp. Also a voltage regulator (from 9V to 3V) and a couple capacitors. The .MOD converter GUI is a program I created in C++ using Qt. It loads in .MOD files, which have several tracks and can contain many "instrument" sound clips. In the .MOD playback, the instruments are repeated at different frequencies to allow some great flexibility. On the PIC, this is not feasible due to memory restrictions, so the PIC synthesizes different instruments using different waveforms (triangle, sawtooth, square, and white noise) with supporting data (volume, diminish, frequency, etc.). The converter GUI allows you to easily see and hear how each track will sound both before and after conversion. It generates .c files as its output, which are easily included in the PIC's project. Every time the circuit is powered on, the PIC pulls a random number seed from its internal EEPROM, generates a random number, and updates the seed. The random number is used to select a song to play from its internal memory. When the song plays to completion, the same process is used to randomly determine the next track. Without RNG, the same songs would play in the same order each time, which is boring. If my webcam had better sound quality, you could hear that it sounds pretty ...



http://www.youtube.com/watch?v=SsBf6Veq-Ps&hl=en

I am showing a method of using a CdS photoresistor to control a standard triac dimmer circuit that is wired to an electric drill motor (a universal motor). The CdS photoresistor is driven by an LED that is controlled by a PWM pin on an arduino microcontroller. This system provides a very easy way to control 120V AC devices with a single PWM pin, and not use any timing code or method to detect the zero-crossing of the AC power since this is done intrinsically in the circuit. It also offers true electrical isolation between the AC line voltage and microcontroller.



http://www.youtube.com/watch?v=7yEABsNyRfo&hl=en

How to calculate the total power consumed in your design. Highlights Silicon Labs C8051F9xx family of ultra low power mixed signal MCUs. Highly-pipelined 8051 microcontroller core that is the fastest and lowest-power in the industry www.silabs.com Highest level of analog peripheral integration and lowest power microcontroller across all operating modes www.silabs.com Lowest power single-chip MCU with an integrated sub-GHz RF transceiver www.silabs.com 8-bit 8051 MCU core with the highest precision analog peripherals, making them ideal for analog and computation intensive applications www.silabs.com Capacitive touch sense MCUs enable implementation of sophisticated and responsive touch interfaces www.silabs.com Automotive and Industrial Microcontrollers with best-in-class analog peripherals and digital signal processing in ultra-small packages www.silabs.com C8051F9xx ultra-low power 8 bit microcontroller has the industry's lowest active mode current consumption, lowest current consumption in sleep modes and fastest wake-up and analog settling time.



http://www.youtube.com/watch?v=QALpBWT_YWo&hl=en

The heart of the LED chaser is the PIC 16F628A microcontroller, IC2. The program that runs on this chip controls the LEDs attached to the output port pins. Resistors R1 thru R8 limit the current through LED1 - LED8 to a safe level that won't damage the PICs I/O ports or LEDs. Resistor R9 provides a pull-up for the input connected to switch S1. R10 holds the PICs MCLR reset signal high. Capacitor C1 is used to decouple the 5 volt power supply to the PIC. The voltage regulator used is a LM2931-5.0, low-drop-out regulator and will maintain regulation with an input voltage down to 6 volts. Input voltage for the LED chaser should be between 6 volts and 14 volts to ensure power dissipation remains within limits. The LM2931-5.0 regulator is designed for battery powered and automotive applications and includes internal current limiting, thermal shutdown, as well as reverse battery connection without damage to itself or the circuit behind it. Capacitor C3 is important and must be fitted to prevent instability of the regulator output. i got this from: picprojects.biz



http://www.youtube.com/watch?v=KcsRgNZ116c&hl=en

Micro-controller interfacing circuit contains power supply, 16F877A PIC, voltage regulator 7805, 10KΩ resistors for the input ports, 330Ω resistors for the output ports. Two transistors C5476 BJT NPN type were added -as a switch- to the drive circuit for the two drive systems to let the PIC activate the relay coil. PIC used for main drive system to control direction and position of the car automaticaly. For main drive system, PIC was programmed to have seven input ports and two out ports. The seven input ports were connected to four magnetic switches and three pushbuttons. The two output ports connected to the Bases of two BJTs in the drive circuit, one to move the car upward and the other to move the car downward. Before connecting the interfacing circuit to the input switches and the main motor, it had been tested on a laboratory breadboard and connected to a DC Wiper motor. The input switches were seven normally open switches connected on the breadboard. Hashemite Uni. - Mechatronics Dept. - Panorama Electrical Elevator Graduation Project 2008/2009. Done by: Ashraf Samir Al-Bitar: aushrufcouzin@hotmail.com Ahmad Sufain Abu-Asfar: ahmadaboasfar@yahoo.com Hazem Jamil Al-Hawajreh: hazemja@hotmail.com Supervised by Dr. Asma Al-Tamimi



http://www.youtube.com/watch?v=Nn2v14eEQ3s&hl=en