A Circuit that fades an LED on and off.

Overview 

These two circuits make a LED fade on and off. The first circuit charges a 100u and the transistor amplifies the current entering the 100u and delivers 100 times this value to the LED via the collector-emitter pins. The circuit needs 9v for operation since pin 2 of the 555 detects 2/3 Vcc before changing the state of the output so we only have a maximum of 5.5v via a 470R resistor to illuminate the LED. 

Schematic 

Parts List 

1x - NE555 Bipolar Timer
1x - LED (Red) 1x - 470 Resistor (1/4W)
1x - 33K Resistor (1/4W)
1x - 100µF Electrolytic Capacitor (16V)
1x - BC547 NPN Transistor
1x - 9V Voltage Battery 

Led Running Lights from

If you are looking for the miniature running LEDs light then here you can get one. The circuit in this site is using the timer 555 1 to 10 decoder 7493 and 1 to 16 decoder 7441.

PART LISTS

RESISTORS
R1	6.8k
VR1	100K
R3, R4	220 Ohm

ICs
IC1	Timer 555IC
IC2	1 to 10 Decoder 7493 IC
IC3	1 to 16 decoder 7441 IC
(N1,N2) IC4	IC 7400 – NAND Gate

DIODES
D1 – D16	LEDs

OTHERS
C1	Capacitor 5μ 25 V
C2	Capacitor 0.01μ
BATT	Battery 5 Volt

Circuit Diagram

Led Runing Light circuit diagram

The circuit consists of three parts. The first part has an oscillator while the second has mod 16 counter 7493. The oscillator is wired in self-triggered mode, and the potentiometer VR1 is used for speed control of the running lights. That is, frequency can be varied from 21 Hz to less than 1 Hz.The counter outputs A, B and C are decoded by IC3 (the decoder 7442) and the outputs obtained on pins 1 to 9 of this IC.The D output of the counter is used for selecting the LEDs from D1 to D8 or D9 to D16. When D is low D1 to D8 are selected, and when D is high D9 to D16 are selected.For the selection of these LEDs, IC4 (7400) NAND gate is used. Thus, a sequential running effect is produced.

This handy mobile bug or cell phone detector from: 

tor, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cellphone from a distance of one and-a-half metres. So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorised video transmission.

The circuit can detect both the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases.

Cell Phone Detector Circuit Schematic

An ordinary RF detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band used in mobile phones. The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3 to 10 cm. So a circuit detecting gigahertz signals is required for a mobile bug.

Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone. The lead length of the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired frequency. The disk capacitor along with the leads acts as a small gigahertz loop antenna to collect the RF signals from the mobile phone.

RADIATION DETECTOR 

Components required:

Sl. No	Components	Range	Quantity
1	IC    CD4033	--------------------------	1
2	Capacitor	1uF 25V	1
3	Resister	2.2k,100Ω	1 each
4	Battery	9V	1
5	LED	RED,GREEN,YELLOW	2 each
6	Areal	---------------------------	1
7	PCB.	---------------------------	1
8	Lead, wire, connecter	----------------------------	----

Working of the circuit:

IC CD 4033is the decade counters with 7 segment display driver. It has seven outputs to drive LED or seven segment display. The clock input (pin1) of IC is very sensitive and readily accepts energy from the electromagnetic radiation even from a long distance. This property of the IC CD4033 is exploited here to measure the intensity of the radiation. The reset pin 15 of IC is connected to C1 and R1 to reset the IC after completing cycle. So that the functioning of IC continues till the input pulses cease.

Areal: A small length wire can be used as a real. A telescopic areal used in pocket radio will give an elegant look to the gadget.

Testing of the circuit:

Bring the areal close to the TV of CRT monitor of computer. All the LEDs light up one by one giving a running pattern. The aped of running light depends on the strength of the radiation. Move away the unit away from the monitor.  As the distance increases, speed of light also decreases. Finally the LEDs stop glowing...  

Full form of computer related terms:
* HTTP - Hyper Text Transfer Protocol.
* HTTPS - Hyper Text Transfer Protocol Secure.
* IP - Internet Protocol.
* URL - Uniform Resource Locator.
* USB - Universal Serial Bus.
* VIRUS - Vital Information Resource Under Seized.
* 3G - 3rd Generation.
* GSM - Global System for Mobile Communication.
* CDMA - Code Divison Multiple Access.
* UMTS - Universal Mobile Telecommunication
System.
* SIM - Subscriber Identity Module.
* AVI = Audio Video Interleave
* RTS = Real Time Streaming
* SIS = Symbian OS Installer File
* AMR = Adaptive Multi-Rate Codec
* JAD = Java Application Descriptor
* JAR = Java Archive
* JAD = Java Application Descriptor
* 3GPP = 3rd Generation Partnership Project
* 3GP = 3rd Generation Project
* MP3 = MPEG player lll
* MP4 = MPEG-4 video file
* AAC = Advanced Audio Coding
* GIF = Graphic InterchangeableFormat
* JPEG = Joint Photographic ExpertGroup
* BMP = Bitmap
* SWF = Shock Wave Flash
* WMV = Windows Media Video
* WMA = Windows Media Audio
* WAV = Waveform Audio
* PNG = Portable Network Graphics
* DOC = Document (Microsoft Corporation)
* PDF = Portable Document Format
* M3G = Mobile 3D Graphics
* M4A = MPEG-4 Audio File
* NTH = Nokia Theme (series 40)
* THM = Themes (Sony Ericsson)
* MMF = Synthetic Music Mobile Application File
* NRT = Nokia Ringtone
* XMF = Extensible Music File
* WBMP = Wireless Bitmap Image
* DVX = DivX Video
* HTML = Hyper Text Markup Language
* WML = Wireless Markup Language
* CD - Compact Disk.
* DVD - Digital Versatile Disk.
* CRT - Cathode Ray Tube.
* DAT - Digital Audio Tape.
* DOS - Disk Operating System.
* GUI - Graphical User Interface.
* HTTP - Hyper Text Transfer Protocol.
* IP - Internet Protocol.
* ISP - Internet Service Provider.
* TCP - Transmission Control Protocol.
* UPS - UninterruptiblePower Supply.
* HSDPA - High Speed Downlink Packet Access.
* EDGE - Enhanced Data Rate for GSM [Global
System for Mobile
Communication] Evolution.
* VHF - Very High Frequency.
* UHF - Ultra High Frequency.
* GPRS - General Packet Radio Service.
* WAP - Wireless Application Protocol.
* TCP - Transmission Control Protocol .
* ARPANET - Advanced Research Project Agency
Network.
* IBM - International Business Machines.
* HP - Hewlett Packard.
* AM/FM - Amplitude/ Frequency Modulation.
* WLAN - Wireless Local Area Network