Electronic Projects   |   Store   |   Schematics   |   Downloads   |   Search  

Circuit-Zone.com - Electronic Projects



FM Broadcast Transmitter
Posted on Sunday, January 8, 2012   •   Category: FM Transmitters


This FM Broadcast Transmitter circuit will transmit a continuous audio tone on the FM broadcast band (88-108 MHz) which could used for remote control or security purposes. Circuit draws about 30 mA from a 6-9 volt battery and can be received to about 100 yards. A 555 timer is used to produce the tone (about 600 Hz) which frequency modulates a Hartley oscillator. A second JFET transistor buffer stage is used to isolate the oscillator from the antenna so that the antenna position and length has less effect on the frequency. Fine frequency adjustment can be made by adjusting the 200 ohm resistor in series with the battery. Oscillator frequency is set by a 5 turn tapped inductor and 13 pF capacitor.


TV Transmitter Circuit
Posted on Wednesday, January 4, 2012   •   Category: TV Transmitters


This is a small TV transmitter circuit which transmits in VHF band, negative sound modulation and PAL video modulation. It is suitable in countries where the B and G system is used.


Capacitance Meter
Posted on Tuesday, January 3, 2012   •   Category: Test and Measurement


RF laboratory often requires capacitance meter for small capacitors in pF range. Such a device can easily be built by yourself. Here, a measurement converter for PC serial port is presented. The frequency of an oscillator is reduced by the target and measured on a PC. The appropriate conversion then allows the direct display of the capacity. The input uses a short and low capacitance probe tip. The opposite pole is clamped to ground cable with a crocodile. The NE555 precision timer receives its operating voltage directly from the serial interface and produces a measurement object without C is a square wave with a frequency of 3.5 kHz. The signal is processed via the CTS input of the interface.


Function Generator XR2206
Posted on Saturday, December 31, 2011   •   Category: Test and Measurement


For measurement purposes in the electronics laboratory is needed again and again signals of different frequency and waveforms. A common function generator provides sine, for example, triangular and square waves. The frequency must be adjustable and at least cover the low frequency range. The low-cost IC XR2206 provides a very simple function generator with only a few external components. XR2206 data sheet provides complete basic circuit for a simple function generator. It requires an operating voltage of 12 V and delivers sine and square wave signals. Instead of the sine wave output is obtained after opening of S1 a triangular output wave. XR2206 IC contains an internal VCO (Voltage Controlled Oscillator, Voltage Controlled Oscillator) with triangular and rectangular output. The capacitor C and the power to determine the frequency at pin 7. With a pot of 2 megohms and a fixed resistor of 1 kOhm variation gives a ratio of 1 to 2000 and may include a range of 10 Hz to 20 kHz sweep.


Phone Spy Transmitter
Posted on Friday, December 30, 2011   •   Category: FM Transmitters


Here is a very simple telephone broadcaster transmitter which can be used to eavesdrop on a telephone conversation. The circuit can also be used as a wireless telephone amplifier. One important feature of this phone transmitter is that the circuit derives its power directly from the active telephone lines, and thus avoids use of any external battery or other power supplies.


Page 28 of 149:   1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   72   73   74   75   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   101   102   103   104   105   106   107   108   109   110   111   112   113   114   115   116   117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   136   137   138   139   140   141   142   143   144   145   146   147   148   149

Circuit-Zone.com © 2017. All Rights Reserved.
AC / DC Innveters
AM Radio
Amplifiers
Antennas
Arduino
Audio Attenuators
Audio DAC
AVR
Battery Chargers
CNC Milling Devices
Counters / Frequency Meters
Fluorescent Lamps
FM Radio / Receivers
FM Transmitters
Frequency Wave Generators
Headphone Amplifiers
iPOD Hacks
LC Meter
LED
Miscellaneous
Motor Controllers
MP3 Players
Oscillators
Oscilloscopes
PC Circuits
PCB
Phone Circuits
PIC
PLL Circuits
Power Supplies
RC Servo Motors
Remote Control
RF Radio Frequency
Robots
Sensors
Solar Circuits
Stepper Motors
Stereo Encoders
Test and Measurement
Timer Circuits
TV Transmitters
USB Circuts
USB Interface Adapters
USB Soundcards / USB Headphones
Video
Volume Control