Owner: Cool Electronic Circuits URL:http://free-electronic-circuit.blogspot.com/ Join Date: Fri, 06 Jun 2008 08:16:34 -0500 Rating:0 Site Description: Cool Circuit Collections : Electronic Circuit, Circuit Design, RF Circuit, AF Circuits, Printed Circuit Boards Prototype Site statistics:Click here
Telemetry Transmitter for Small Animal 2008-06-03 11:23:50 The goal of this project was to build a small, cheap, light-weight telemetry transmitter to attach to a small animal. This version uses a commercial, low-power transmitter, the Radiotronix RCT-433-AS. The design worked well, but has a relatively high current draw of about 500 microamps. A CR1620 lithium coin cell runs the circuit for about a week. The current version uses a pair of CMOS oscillator Read more:Animal
, Small
, Transmitter
River Level Monitoring System - RiverSpy2 #2 2008-06-03 11:14:46 How to get startedAs you can see from the picture at part #1, the original system was prototyped using veroboard. If you are not familiar with electronics, you will find it easier to build using a printed circuit board (pcb). The layout files are given below. You can order from within the expresspcb program. The MiniBoard service at expresspcb costs US$83 for 3 boards, including a courier service Read more:River
, System
River Level Monitoring System - RiverSpy2 #1 2008-06-03 11:09:21 System OverviewThe diagram below gives an overall picture of the system. At the river end, the system is broken into two parts. At the bottom of the river, bolted to an existing stick gauge (or some other convienient location) is a differential pressure sensor. This sensor measures the difference in pressure between the athmosphere and the bottom of the river. To make this differential measureme Read more:River
, System
Video Amplifier with Sync Stripper and DC Restore (EL8102) 2008-05-20 02:38:59 IntroductionThe circuit in Figure 1 transmits 200MHz (-3dB bandwidth) video signals while stripping off the sync pulse and performing DC restoration. It is configured for a typical video cable driver application driving a double-terminated 75Ω load, where the EL8102 (IC3) is configured for a gain of +2 to ensure unity gain throughout.Sync StrippingIn component video systems it is frequently nece Read more:Amplifier
, Restore
, Stripper
Wideband UHF TV Signal Amplifier 2008-05-20 02:26:14 This UHF wideband signal amplifier has a total gain of 10 to 15 dB in the 400 - 850 MHz domain frequency so it can be used where the tv signal is weak. For UHF TV signal amplifier to work correctly, you need to cut the components pins as short as possible. C1, C2, C6, C7 are SMD type (surface mounted). This antenna tv amplifier or uhf wideband amplifier need to be build inside of a metal box an Read more:Amplifier
, Wideband
Audio Millivoltmeter as Audio Test Equipment 2008-05-13 16:04:59 When performing any tests on an audio system, some form of measuring device is essential. Digital multimeters are not useful, since they will not give the true picture of what is happening, and most have a fairly limited frequency range. An oscilloscope equipment is the ideal tool for audio test, but not all hobbyists can afford the outlay for a scope, and would find justifying the not inconsider Read more:Audio
, Equipment
Water Activated Alarm 2008-05-08 02:10:37 The Electronic circuit uses a 555 timer wired as an astable oscillator and powered by the emitter current of the BC109C. Under dry conditions, the transistor will have no bias current and be fully off. As the probes get wet, a small current flows between base and emitter and the transistor switches on. A larger current flows in the collector electronic circuit enabling the 555 osillator to sound.A
Radio Wave Alarm 2008-05-07 03:55:40 This alarm circuit is sure to have the police beating a path to your door - however, it has the added advantage of alerting you to their presence even before their footsteps fall on the doormat.The circuit transmits on Medium Wave (this is the small problem with the police). IC1a, together with a sensor (try a 20cm x 20cm sheet of tin foil) oscillates at just over 1MHz. This is modulated by an aud Read more:Radio
Almost Ultrasonic Motion Sensor 2008-05-07 03:51:56 This sensor uses the sound generator in the RCX to make a 15kHz audio tone, which is almost ultrasonic. The tone is received with circuitry similar to my Sound sensor. The output of a crystal microphone MIC is amplified and then only the very high frequencies are further amplified (see plot). This signal is enveloped detected with a diode D1 and capacitor C1. The voltage on the capacitor will equa Read more:Almost
, Motion
, Sensor
Audio Video Transmitter 2008-05-04 11:07:47 Small Circuit to send your Audio
Video from DVD player or satellite receiver to VHF RF signal. This circuit connected to TV RF input via 75 ohm cable or telescopic antenna. Don’t use this circuit for more power without filter and use antenna only to transmit. Frequency range on vhf band about 50-250 MHz.You can change the transistor for transmitting on UHF band. Keep the components lead shortly. Read more:Transmitter
Telemetry Transmitter System 2008-05-04 10:57:16 This project is a multi sensor telemetry system with Frequency Division Multiplexing (FDM).This Telemetry System
acquires several different sensor inputs, FM modulates each level by manipulating Direct Digital Synthesis increment values, transmits the resulting signal on a commercial FM radio band, and receives and decodes the original sensor levels.Wireless Telemetry System - LinkMiniature Telem Read more:Transmitter
Make Printed Circuit Boards 2008-05-01 14:26:31 Creating Printed Circuit
Boards (PCBs) is easy and fun for the whole family! But read the disclaimer -- heat and corrosive chemicals are dangerous. After you've prototyped and tested your circuit design, creating a PCB will provide a sturdy and reliable backbone for your circuit and will give your project a professional finished quality. Using PCBs can even help reduce the time you spend building
What's Electronic circuit 2008-04-30 06:56:11 An electronic circuit is an electrical circuit that connects active and passive electronic components such as resistors, capacitors, microprocessors, transistors or vacuum tubes.The electronic circuits are typically built using a printed circuit board (PCB) that is used to mechanically support and electrically connect electronic components.The continued miniaturization and savings in power allows Read more:Electronic
Privacy Policy 2008-04-30 06:32:29 Privacy Policy
for Free Electronic Circuit (FEC)If you require any more information or have any questions about our privacy policy, please feel free to contact us by email at fecircuit@telkom.net.Log FilesLike many other Web sites, FEC makes use of log files. The information inside the log files includes internet protocol ( IP ) addresses, type of browser, Internet Service Provider ( ISP ), date/t Read more:Privacy
, Privacy Policy
Very Low Power UHF RF Transmitter with CC1050 Chip 2008-04-30 06:30:58 CC1050 is RF Integrated Circuit UHF transmitter designed for very low power and very low voltage wireless applications. The circuit is mainly intended for the ISM Industrial, Scientific and Medical) and SRD (Short Range Device) frequency bands at 315, 433, 868 and 915 MHz, but can easily be programmed for operation at other frequencies in the 300-1000 MHz range.The main operating parameters of C Read more:Transmitter
UHF TV RF amplifier 5W 2008-07-12 03:46:02 This electronic circuit is a RF Power Amplifier for driving small UHF TV transmitters. Its gain is 7dB and can amplify a signal between 450-800 MHz. You can drive the circuit with 1 to 1,5 Watts signal. Better use double layer PCB with the second layer connected to earth. Use a stabilized power supply 25 volts and at least 5Amps.The transistor case is the SOT-122A and be careful because the transi
Telephone Hybrid Circuit 2008-07-12 03:34:56 This electronic circuit is a telephone hybrid. It is intended to be used to create an easy connection beetween telephone line and studio equipment. Connect the two wires of the telephone line to the tip and ground of the line input and connect the telephone itself to the phone output on the tip and ground only.Now the hybrid is interfaced (fully balanced) between your telephone and its connection Read more:Circuit
, Hybrid
Oxygen Sensor Simulator 2008-07-13 18:05:35 This electronic circuit is an oxygen sensor simulator that built on a protoboard. Note the cigarette lighter plug used for power source. The adjustment knob is at the left, and the switch is on the right. The red indicator LED is in the middle. Only use red, because the voltage drop of the LED is part of the circuit!The schematic diagram for the simulator. Closing the switch engages the simulator. Read more:Oxygen
, Sensor
, Simulator
Fan Controller with an LM76 as Temperature Estimator 2008-10-06 04:30:49 This temperature sensor circuit is to control a small fan controller. An LM76 as temperature 'estimator' used in this project. To make it a little more interesting, an LPH7653 display to show the heat sink temperature and fan status.
This projects used an AT90S8535, but as the schematic shows, a lot of the controllers pins are left unused. You may want to select a smaller AVR. The choice will mai Read more:Temperature
Ultrasonic Pest Repellant 2008-09-30 22:03:00 This electronic circuit is an ultrasonic pest repellant are repelled by variabble ultrasonic frequency in the range of 30 kHz to 50 kHz. Thus to increase the effectiveness, frequency of ultrasonic oscillator has to be continuously varied between certain limits.
By using this circuit design, frequency of emission of ultrasonic sound is continuously varied step-by-step automatically. Here five st
Mosquito Repellant Circuit with BC547 2008-09-30 21:50:19 This Moosquito repellat circuit uses two BC547 transnistor as astable multibibrator. The Astable Multivibrator, which is generally used as a signal generator, is once again used here to generate the desired frequencies. It is an excellent example of the fact, how versatile simple basic electronic circuit can be.
Astable Multivibrator Circuit
Operation
When T1 is conducting T2 is off and when T2 Read more:Mosquito
Insect Repellant with CMOS 4047 2008-09-30 21:36:01 This elctronic circuit is an insect repellant using IC CMOS 4047. Repell those repugnent insects from your Garden this Summer with this insect repellant circuit.
This insect repellant circuit designed by Graham Maynard the circuitry consists of a phase locked loop (CMOS 4047) wired as a 22KHz oscillator. The output is amplified by a pair of complimentary output transistors and drives a Motorola 3
Three in One Tester for Audio, Diode, and Circuit 2008-09-26 14:52:25 This electronic schematic circuit is a test circuit for audio, diode and circuit. This very handy simple solid state battery operated tester. It works on two 1.2-1.5 AA-batteries.
This three in one tester can be used for :
audit AF/LF signal
circuit tester
diode tester
1 KHz tone generator
When you switch S1 OFF the diode/circuit testerschematic can be used.
Source: Read more:Audio
, Circuit
, Tester
, Three
Making Really Good Homemade Printed Circuits Boards (PCBs) 2008-09-20 13:50:44 Want to know how to make really really good homemade Printed circuit boards? This taken is from original posting of Mike's Electronic Stuff. This page contains a guide to producing consistently high quality PCBs quickly and efficiently, particularly for professional prototyping of production boards. Unlike most other PCB homebrew guides, emphasis is placed on quality, speed and repeatability rath Read more:Circuits
Battery Low Voltage Beeper 2008-11-17 07:06:41 This electronic circuit is an alarm circuit for low battery condition. It provides an audible and visual low voltage warning for 12V battery powered devices. When the battery voltage is above the set point (typically 11V), the circuit is idle. If the battery voltage should fall below the set point, the LED will light and the speaker will emit a periodic beeping sound to warn of the impending loss Read more:Voltage
2-25V 5A Power Supply LM338 2008-11-14 08:46:15 This power supply circuit uses a LM338 adjustable 3 terminal regulator to supply a current of up to 5A over a variable output voltage of 2V to 25V DC. It will come in handy to power up many electronic circuits when you are assembling or building any electronic devices. The schematic and parts list are designed for a power supply input of 240VAC. Change the ratings of the components if 110V AC powe Read more:Power Supply
, Supply
ICL7107 Digital LED Voltmeter 2008-11-12 01:27:24 This circuit is a digital voltmeter with LED display. It's ideal to use for measuring the output voltage of your DC power supply. It includes a 3.5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199.9V with a resolution of 0.1V. The voltmeter is based on single ICL7107 chip and may be fitted on a small 3cm x 7cm printed circuit board. The circuit should be s Read more:Digital
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