Music Reactive LED Chaser Light Circuit 12

 

7 Volt to 40 Volt Boost Converter 555 ic

 

VU Meter

 The Stereo VU Meter PC board with the components fitted. Only the battery and speaker are external, connected to flying leads. A close up of the completed unit. The overlay makes construction easy. Make sure the left-hand row of resistors starts with 47k at the bottom and 4k7 at the top. I saw one unit with the whole row reversed. It made very little difference to the performance of the unit, but it was not quite as sensitive as the correct version

The BOOTSTRAP circuit connects to the LED bar graph via A B C. Only one BOOTSTRAP circuit is provided on the board. It is capable of driving both bar graphs in a mono mode. For a stereo readout, you will need to build another bootstrap circuit. This will give a STEREO SOUND LEVEL INDICATOR.  

 

ROBOT-1 light-detecting circuits

 ROBOT-1 A simple robot can be made with 2 motors and two light-detecting circuits, (identical to the circuit above). The robot is attracted to light and when the light dependent resistor sees light its resistance decreases. This turns on the BC547 and also the BC557. The shaft of the motor has a rubber foot that contacts the ground and moves the robot. The two pots adjust the sensitivity of the LDRs. This kit is available from Velleman as kit number MK127.

PHONE TAPE

 PHONE TAPE - 2 The circuit is turned off when the phone line is 45v as the voltage divider made up of the 470k, 1M and 100k puts 3.5v on the base of the first BC557 transistor. If you are not able to get to cut the lead to the phone, the circuit above will record a conversation from an extension lead. The remote plug must be wired around the correct way for the motor to operate.

LED TORCH with 1.5v SUPPLY LED TORCH

 

LED TORCH with 1.5v SUPPLY This simple circuit will illuminate a super-bright white LED to full brightness with 28mA from a 1.5v cell. The LED is 20,000mcd (20cd @ 15° viewing angle) and has an output of approx 1lumen. The transformer is wound on a small ferrite slug 2.6mm dia and 6mm long. It is made from F29 ferrite material as the circuit operates at a high frequency (100kHz to 500kHz). The efficiency of the circuit revolves around the fact that a LED will produce a very high output when delivered pulses, but the overall current will be less than a steady DC current. BC 337 has a collector-emitter voltage of 45v. (BC338 has 25v collector-emitter voltage rating.) The voltage across the transistor is no more than 4v as the LED absorbs the spikes. Do not remove the LED as the spikes from the transformer will damage the transistor. The circuit will drive 1 or 2 while LEDs in series.

 

LIGHTENING DETECTOR

 LIGHTENING DETECTOR Clouds can carry such huge electric charges that may to cause lightning flashes of thousands of volts. It is really a fascinating phenomenon. When a lightning flash takes place a broad spectrum of radio-frequencies is generated. In this broad spectrum there is special intense emissions of the VLF (Very Low Frequency) band. This project will allow you to build a receiver to pick up a band near 300 KHz. An LED will flash to indicate the lightning flashes. THE CIRCUIT The radio-signal generated by the lightning flash is picked up by the telescopic antenna with the help of a 10mH choke. The choke L1 resonates with the antenna and allows current to flow into the receiver circuit. The L2 of 330uH in parallel with the 680pF capacitor C1 forms a tuned circuit for 300KHz. This parallel-tuned tank circuit is coupled to the base of Q1 via D2. The amplified radio signal is again coupled into the base of Q2. Transistors Q2 and Q3 form an LED flasher circuit. Transistor Q4 is the LED driver. The flasher is biased so that when VR1 is carefully adjusted the LED flashes only when a radio burst appears at the input due to a lightning flash. Positive feedback ensures the LED to be full on. The circuit quickly resets by charging C4 capacitor through diode D1. The circuit draws only about 100uA in idle state. Therefore it can run on two cells for many hours.

12v LAMP DIMMER

12v LAMP DIMMER Here is a 12 volt @ 2 amp lamp dimmer that can be used to dim a standard 25 watt bulb by controlling the duty cycle of a astable 555 timer oscillator. When the potentiometer is at the up position, the capacitor will charge quickly through both 1k resistors and the diode, producing a short positive interval and long negative interval which dims the lamp to near darkness. When the potentiometer is at the lower position, the capacitor will charge through both 1k resistors and the 50k potentiometer and discharge through the lower 1k resistor, producing a long positive interval and short negative interval which brightens the lamp to near full intensity. The duty cycle of the 200Hz square wave can be varied from approximately 5% to 95%. The two circuits below show how to connect the lamp to either the positive or negative side of the supply.

But the first circuit has a mistake and some components are not needed. The 555 will sink 300mA and it can be connected directly to the output transistor - you don't need the buffer transistor. When the 555 goes HIGH, the voltage on Pin 3 is 1.5v lower than the 12v rail and thus the transistor does not turn off. The two diodes in the circuit below are needed to drop an additional 1v so the transistor turns off.
 

10 OUTPUT LED SEQUENCER

 10 OUTPUT LED SEQUENCER Here is 10 output LED sequencer. After the last LED is illuminated, the circuit is reset. This circuit is build around readily available, low cost components - a 555 and decade counter CD4O1 7. The timer IC NE555 is wired as an astable multivibrator that produces 6Hz clock at its output pin 3. The 4017 is a CMOS decade counter with 10 outputs. Inputs include a CLOCK (Pin 1 4), a RESET (Pin 15), and a CLOCK INHIBIT (Pin 13). The clock input connects to a Schmitt trigger for pulse shaping and allows slow clock rise and fall times (not needed in our case). The counter advances one output at the rising edge of the clock signal if the CLOCK INHIBIT line is low. A high RESET signal resets the counter to the zero output. The circuit may be configured for counts less than 10 by connecting RESET to an output pin (one after the desired count). Thus, a five stage sequencer can be made by connecting pin 15 to pin 1. A CARRY-OUT signal (pin 12) can be used to clock subsequent stages in a multi-device counting chain. The output from 1C2 pin 3 is connected to clock pin (pin 14) of the IC3 for sequencing operations. NPN transistors Q1- Q10 are used to increase the output current for the LEDs which is set by the common 150 ohm resistor. In the circuit, only one of the outputs is HIGH at any one time and the output advances by one count with every clock pulse.

REACTION TIMER GAME

  REACTION TIMER GAME 

 This is a game for two players. Player 1 presses the START button. This resets the 4026 counter chip and starts the 555 oscillator. The 555 produces 10 pulses per second and these are counted by the 4026 chip and displayed on the 7-Segment display. The second player is required to press the STOP button. This freezes the display by activating the Clock Inhibit line of the 4026 (pin 2). Two time-delay circuits are included. The first activates the 555 by charging a 10u electrolytic and at the same time delivering a (high) pulse to the 4026 chip to reset it. The second timer freezes the count on the display (by raising the voltage on pin 2) so it can be read.

TV REMOTE CONTROL JAMMER

 TV REMOTE CONTROL JAMMER This circuit confuses the infra-red receiver in a TV. It produces a constant signal that interferes with the signal from a remote control and prevents the TV detecting a channel-change or any other command. This allows you to watch your own program without anyone changing the channel !! The circuit is adjusted to produce a 38kHz signal. The IR diode is called an Infra-red transmitting Diode or IR emitter diode to distinguish it from a receiving diode, called an IR receiver or IR receiving diode. (A Photo diode is a receiving diode). There are so many IR emitters that we cannot put a generic number on the circuit to represent the type of diode. Some types include: CY85G, LD271, CQY37N(45¢), INF3850, INF3880, INF3940 (30¢). The current through the IR LED is limited to 100mA by the inclusion of the two 1N4148 diodes, as these form a constant-current arrangement when combined with the transistor and 5R6 resistor

tda7293

 

pir sansor