http://electroschematics.com electronics schematics, electronic circuits, hobby diy Thu, 24 Jul 2008 18:31:08 +0000 http://backend.userland.com/rss092 en This mic preamp uses the low noise IC uA739. The circuit is an example of how a good preamplifier can be designed for dynamic microphones. The IC houses two identical integrated preamp circuits. The second preamp is used in identical manner for the second channel of the stereo microphone. Diagram bellow ... http://electroschematics.com/506/dynamic-mic-preamplifier/ The human heartbeat can be made audible by using this cardiophone circuit. It is basically an audio circuit coupled to a probe made specially for the purpose of picking up electric signal from the human heart. To get the best signal, place the probe's electrodes to a point close to the ... http://electroschematics.com/502/cardiophone/ Service manual for TFT-LCD TV/Monitor Samsung NK15A and NK17A. Service manual contents: 1. Precautions 2. Product Specifications 3. Disassembly & Reassembly 4. Alignment & Adjustments 5. Troubleshooting 6. Exploded View & Parts List 7. Electrical Parts List 8. Block Diagram 9. Wiring Diagram 10. Schematic Diagrams 11. Panel Description Download Samsung TFT NK15A, NK17A service manual guide http://electroschematics.com/500/samsung-tft-nk15a-nk17a-service-manual/ Service manual for Sony FWD-42PV1A FLAT WIDE DISPLAY, REMOTE COMMANDER RM-980, SPEAKER SYSTEM SS-SP42FW. Sony FWD-42PV1A service manual contents: - service overview - service mode and adjustment - troubleshooting - spare parts - block diagram Download Sony FWD-42PV1A service manual guide http://electroschematics.com/498/service-manual-sony-fwd-42pv1a/ Take a look at this mini transmitter which can be used as a bug transmitter or for spy transmitter too. It uses a single IC 74F13, one coil, a capacitor, one trimmer, one resistor and ofcourse one electret mic. It is so easy to build and can give you a ... http://electroschematics.com/496/74f13-mini-bug-transmitter/ A simple 25W fm radio amplifier used as a final stage for a 2.5W transmitter. I has a total gain of 10 dB and needs a 12V / 3A power supply. It is equiped with KT925W or BLY88, BLY89C. Use a very good headsink because this transistor get very hot ... http://electroschematics.com/494/fm-radio-amplifier-25w/ To find the power gain ratio corresponding to a 3 dB change in level, use the formula: The table showing the amplification factor if you know the power gain in dB power gain dBamplification factor 11.26 21.58 32 42.5 53.16 64 75 86.3 97.95 1010 1112.6 1215.8 1320 1425 1531.6 1640 1750 1863 1979.5 20100 For example if we use BLY90 which has a power gain of 5 dB at 12.5V and 175MHz ... http://electroschematics.com/492/amplification-factor-power-gain-and-db/ Use this fm antenna amplifier in areas where the signal reception of FM stations is too bad. This circuit is just the right thing to do it. It is designed in such a way that the supply current powering it flows through coaxial cable. With this technique, an extra cable to ... http://electroschematics.com/488/fm-antenna-amplifier/ Sony LCD TV KLV-S26A10/S32A10/S40A10 service manual contains: SELF-DIAGNOSIS FUNCTION .................... 1-1 2. DISASSEMBLY ............................................ 2-1 2-1. KLV-S26A10/S32A10 ....................................... 2-1 2-1-1. STAND ASSY REMOVAL .......................... 2-1 2-1-2. REAR CABINET ASSY REMOVAL .......... 2-1 2-1-3. H1E BOARD REMOVAL ............................ 2-2 2-1-4. VESA BRACKET ASSY REMOVAL ......... 2-2 2-1-5. SIDE BRACKET ASSY AND S1 TOP SHIELD REMOVAL ............. 2-3 2-1-6. G2 AND ... http://electroschematics.com/484/sony-klv-s26a10s32a10s40a10-service-manual/ The function of this automatic volume control circuit is to amplify signals without distorting its dynamic compression. The amplitude differences in the signal are levelled off and the disturbing effect vanish. With this tehnique, overcompensation in the volume is avoided. The circuit is used to automatically control the volume levels ... http://electroschematics.com/479/automatic-volume-control/