Circuit AMPLIFICADOR 700WATTS 2SC5200 - 2SA1943 ESQUEMA - 700WATTS AMPLIFIER 2SC5200 - 2SA1943 SCHEME Schematics

AMPLIFICADOR 700WATTS 2SC5200 - 2SA1943 ESQUEMA - 700WATTS AMPLIFIER 2SC5200 - 2SA1943 SCHEME

Este esquema é um amplificador de potência profissional, de alta potência em classe AB.
Os amplificadores de alta potência na classe AB não são muito comuns, e somente são utilizados em sistemas de sonorização onde o objetivo é alcançar a máxima fidelidade e também um timbre bastante macio, aveludado e natural em toda a faixa audível e um bom fator de amortecimento.

READ MORE... http://www.te1.com.br/2011/03/amplificador-de-660-watts-rms-4-ohms-mono/#axzz1NgiHZ6rC

THIS IS THE PICTURE BELONGS TO THE WEBSITE : http://www.te1.com.br

read more "Circuit AMPLIFICADOR 700WATTS 2SC5200 - 2SA1943 ESQUEMA - 700WATTS AMPLIFIER 2SC5200 - 2SA1943 SCHEME Schematics"

Circuit Infrared Radar (IR) System Schematics

Infrared Radar (IR) System

Chris from PyroElectro.com has a abundant commodity about a do-it-yourself alarm arrangement body with PIC18F452. It’s a abundant amusement activity although the schematic is actual complicated. This activity uses three capital accessories to actualize the claimed alarm system. The IR Ambit sensor gives output, the pic microcontroller processes it and again displays the achievement on the led array.

The ambition of this activity is to actualize a alive ir alarm system. The arrangement will alone be appropriate to admeasurement abutting adjacency at an bend of 90 degrees as apparent in the archetype above. The ambit of arrangement is almost 4-30cm, 20-150cm & 1m-5.5m depending aloft which sensor you accept to use. Below is an archetype of what abbreviate ambit claimed alarm could be acclimated for.

read more "Circuit Infrared Radar (IR) System Schematics"

Circuit Electronic Amplifier TDA2006 Schematics

Amplifier TDA2006 Kit

This amplifier circuit is build around the tda2006 integrated circuit who features a short circuit protection system, and a thermal shutdown system in case of overheating.

With a 12v power supply the circuit delivers 12w on a 4 ohm speaker and 8w on a 8 ohm speaker. The integrated circuit can work with a power supply between 6v and 15v max.

Amplifier TDA2006 Circuit

The TDA2006 is a monolithic integrated circuit in Pentawatt package, intended for use as a low frequency class "AB" amplifier. At ±12V, d = 10 % typically it provides 12W output power on a 4Ω load and 8W on a 8Ω . The TDA2006 provides high output current and has very low harmonic and cross-over distortion.

Further the device incorporates an original (and patented) short circuit protection system comprising an arrangement for automatically limiting the dissipated power so as to keep the working point of the output transistors within their safe operating area. A conventional thermal shutdown system is also included. The TDA2006 is pin to pin equivalent to the TDA2030

read more "Circuit Electronic Amplifier TDA2006 Schematics"

Circuit Electronic Circuit Amplifier TDA7381 Schematics

IC TDA7381

The TDA7381 is a class AB audio power amplifier in Flexi watt25 package designed for car radio applications. You you can also use this circuit for other purposes. Thanks to the fully complementary PNP/NPN output configuration the TDA7381 allows a rail to rail output voltage swing with no need of bootstrap capacitors.

The extremely reduced components count allows very compact sets. The on-board clipping detector simplifies gain compression operations. The fault diagnostics makes it possible to detect mistakes during Car- Radio assembly and wiring in the car.

This is a 4 x25 Watt audio amplifier circuit using IC TDA7381. The amplifier circuit require few external components and is very easy to build. This amplifier is designed for car audio system, but you may use the circuit for another application such as mp3 player, computer etc

Amplifier TDA7381 Circuit

Absolute maximum ratings of IC TDA7295 IC : Operating supply voltage = 18 V, DC supply voltage = 28 V, Peak supply voltage (t = 50 ms) = 50 V, Output peak current Repetitive (duty cycle 10 % at f = 10 Hz) = 3 A, Output peak current Non repetitive (t = 100 μs) = 4A, Power dissipation, (Tcase = 70 °C) = 80 W, Junction temperature = 150 °C, Storage temperature = -40 to 150 °C

read more "Circuit Electronic Circuit Amplifier TDA7381 Schematics"

Circuit Electronic Amplifier TDA2002 Schematics

Amplifier TDA2002 Kit

This is a power amplifier circuit which built using a TDA2002 power amplifier IC module. These are replacements for the original LM383 which is no longer available.

It is easy to build and has a minimum of external components. The module has both short circuit protection and thermal protection. It can drive loads as low as 1.6 ohm and is capable of delivering over 10 watts from a 16 V supply.

The small amplifier is constructed around the TDA2002 IC, capable of delivering 4Wrms at 4ohms. The supply voltage may be anywhere between 8 and 18V, and the IC will accept transient voltage peaks of up to 28V without damage. The additional features of TDA 2002, very low number of external components, ease of assembly, space and cost saving, are maintained. The device provides a high output current capability (up to 3.5A) very low harmonic and cross-over distortion. Completely safe operation is guaranteed due to protection against DC and AC short circuit between all pins and ground, thermal over-range.

Amplifier TDA2002 Circuit

component: R1 potentiometer 10 k ohm, R2 220 ohm 1/4 watt resistor, R3 2R2 ohm 1/4 watt resistor, R4 1 ohm 1/4 watt resistor, IC1 TDA2002 amplifier module 1, Heat sink, C110uF/50V electrolytic capacitor, C2 470uF/16V electrolytic capacitor, C3 2200uF/25V electrolytic capacitor, C4 100 nF mylar 1, C5 100 nF monoblock 1, C6 100uF ecap 1.

read more "Circuit Electronic Amplifier TDA2002 Schematics"

Circuit Electronic Circuit Amplifier BD139 Schematics

Amplifier BD139 Kit

As a headphone amplifier, this design is very similar to others on the ESP site, but the main difference is that this one (and P70) has been built and fully tested. The design is fairly standard, and every variation was checked out before arriving at the final circuit. A photo of the prototype is shown below, and at only 64 x 38mm (2.5 x 1.5 inches) it is very small - naturally, the heatsink is not included in the dimensions.

In short, the amp can be used anywhere that you need an opamp with more output current than normally available. Since most are rated for around ±20-50mA, general purpose opamps are not suitable for driving long cables or anywhere else that a relatively high output current is needed.

The output transistors are biased using only resistors, rather than constant current sources. Extensive testing showed that using current sources made no discernible difference to performance, but increased the complexity and PCB size. Using separate caps for each biasing diode does make a difference though - and although it is relatively minor, the use of the two caps is justified IMHO.

Amplifier BD139 Circuit

The amplifier itself is fairly conventional, and is very similar to another shown on this site (see Project 24). This amplifier does not include the active volume control, because in general it is far easier to get a good log pot (or simply 'fake' the pot's law as described in Project 01). Likewise, it does not include the cross-feed described in Project 109. If this is desired, it is very easy to implement on a small piece of tag board, or even 'sky hook' the few components off the bypass switch. Full details of how to do this will be included in the construction guide when PCBs are available.

The bias diodes should be 1N4148 or similar - power diodes are not recommended, as their forward voltage is too low. This may result in distortion around the crossover region, where one transistor turns off and the other on. As shown, crossover distortion is absolutely unmeasurable with the equipment I have available.

read more "Circuit Electronic Circuit Amplifier BD139 Schematics"

Circuit TDA2822 AMPLIFICADOR DE AUDÍFONOS - HEADPHONE AMPLIFIER Schematics

TDA2822 AMPLIFICADOR DE AUDÍFONOS - HEADPHONE AMPLIFIER

A stereo power amp designed for use in portable players and radios. A 3V supply can be used to drive headphones providing 20mW in 32 Ohms per channel, and a 9V supply will provide 1W in 8 Ohm per channel for small loudspeakers.

READ MORE..... http://construyasuvideorockola.com/proy_audifon.php

THIS IS THE PICTURE BELONGS TO THE WEBSITE: http://construyasuvideorockola.com

read more "Circuit TDA2822 AMPLIFICADOR DE AUDÍFONOS - HEADPHONE AMPLIFIER Schematics"

Circuit Light Relay Circuit Schematics

This module has many application in the industry. It is usually present in elevator doors ,automatic doors, furnaces, machine security systems, printers,etc. It is also used to count people, or to detect bodies.

Electronic Circuit Description
Try place LDR on light,see what happened.The relay RL1, Still in not active condition.When you block LDR from light or in darkness,sensing transistor T2 will on, this signal then amplified and drive T1 to turns on RL1,Relay. Then F and OUT1 are connected.You can used the relay output to turn on something useful.

Electronic circuit Diagram Component List

[Resistor]

R4 - 1 - 10 ohm , R1- 1 - 270 ohm , R5- 1 - 1K

R6- 1 - 4K7 , R3- 1 - 10K LDR, R2- 1 - Adjustable 4K7

[Capacitor]

C1- 1 - 100nF , C2- 1 - 100nF (electrolytic)

[Transistor]

T1 - 1 - 547 , T2 - 1 - 337

[Miscellaneous]

Diode D1 - 1 1N4148 , Photoelectric Cell - 1 , Relay -1

read more "Circuit Light Relay Circuit Schematics"

Circuit 3V FM transmitter Circuit Schematics

3V FM transmitter Circuit

This 3V FM transmitter Circuit is about the simplest and best basal transmitter to body and accept a advantageous transmitting range. It is decidedly able admitting its baby basic calculation and 3V operating voltage. It will calmly access over three floors of an accommodation architecture and go over 300 meters in the accessible air.

The ambit is basically a radio abundance (RF) oscillator that operates about 100 MHz. Audio best up andamplified by the electret microphone is fed into the audio amplifier date congenital about the aboriginal transistor. Output from the beneficiary is fed into the abject of the additional transistor area it modulates the beating abundance of the catchbasin ambit (the 5 about-face braid and the trimcap) by capricious the alliance capacitance of the transistor. Alliance capacitance is a action of the abeyant aberration activated to the abject of the transistor. The catchbasin ambit is affiliated in a Colpitts

Place the transmitter about 10 anxiety from a FM radio. Set the radio to about about 89 - 90 MHz. Walk aback tothe FM transmitter and about-face it on. Spread the ambagious of the braid afar by about 1mm from anniversary other. No coilwinding should be affecting addition winding. Use a baby spiral disciplinarian to tune the trim cap. Remove the screwdriverfrom the trim spiral afterwards every acclimation so the LC ambit is not afflicted by devious capicitance. Or use a plasticscrewdriver. If you accept adversity award the transmitting abundance again accept a additional being tune up and downthe FM punch afterwards every adjustment. One abounding about-face of the trim cap will awning its abounding ambit of capacitance from 6pF to 45pF. The accustomed FM bandage tunes in over about one tenth of the abounding ambit of the affability cap.

So it is best to acclimatize it in accomplish of 5 to 10 degrees at anniversary turn. So affability takes a little backbone but is not difficult. The acumen that there charge be at atomic 10 ft. break amid the radio and the FM transmitter is that the FM transmitter emits harmonics; it does not alone afford on one abundance but on several altered frequencies abutting to anniversary other. You should accept little adversity in award the Tx abundance back you chase this procedure.

read more "Circuit 3V FM transmitter Circuit Schematics"

Circuit 3M Wireless Intercom System Schematics

3M Wireless Intercom System circuit Diagram

The afterward schematic shows the 3M Wireless Intercom Arrangement Circuit and Components Diagram. The 3M Wireless Intercom Arrangement is advised for aerial reliability, compactness, and affluence of service. It is advised to accommodate two-way, radio-frequency audio advice in quick account drive-through restaurants and accessibility stores. The arrangement can be programmed to accomplish on any one of 16 altered channels to accommodate high-quality audio achievement and abate the achievability of arrest amid adjoining wireless systems.

read more "Circuit 3M Wireless Intercom System Schematics"

Circuit Electronic Circuit 5 Watt FM Amplifier Schematics

5 Watt FM Amplifier Board

This design is a 2 stage amplifier that has about 17db of gain, suitable for an input of 50 to 100 MW. Its basically a Veronica 5 watt vco transmitter, without the vco.

The transistors are a 2N4427 and a MRF237. Output power is 2.5 to 5 watts, depending on input drive and dc voltage. At 13.7 vdc with 50 MW of drive, the output was 2.5 watts. The maximum dc voltage recommended is about 15-16 volts.

The unit is constructed with copper clad board, a large piece is used as the construction surface and is mounted into a case. Other board material is cut into small pads, then glued to the construction surface for part connections. A heatsink is needed for the both transistors, a small "top hat" style will work for TR1 but TR2 requires a larger heatsink thats attached to the case. This is made from aluminum L stock, a 3/8" hole and a slot is made for TR2 to fit snuggly in. Up to 7-8 watts output is possible with this amp, but for continious duty only 5 watts maximum output is recommended.

5 Watt FM Amplifier Circuit

A fan is required and it is mouted on the case lid, with holes drilled for ventilation. The chokes H1, H2 and H3 are 5 turns of 30 awg wire on a ferite bead and choke H4 is a 330 ohm 1/2 watt resistor with 14 turns of 30 awg with a ferite bead on each end. Ferite beads need to be of type 43 material. The coils L1, L2 and L3 are made of 18 awg tinned wire. A 1.5 amp 3ag fuse is part of the dc power cord assembly. I used BNC coax connectors for input and output, however SO-239 or F type connectors would be fine too.

read more "Circuit Electronic Circuit 5 Watt FM Amplifier Schematics"

Circuit Electronic Circuit PIC16f628a Clock Schematics

PIC16f628a Clock

The clock is regarding one of the oldest human inventions, where it’s meeting the need to measure the time in the natural units, such as second, minute, day, month and the year. However, if you want to measure the time accurately, you’ll need the help of some devices.

Brother Paul has invented the first record of a minute hand on a clock in 1475. Alexander Bain, a Scottish clockmaker was the first inventor that patented the electric clock in 1840! Although the digital clock is one of the most common items in nowadays.

PIC16f628a Database

It is a small adjustable clock/date with thermometer function based on PIC16F628 or PIC16F84 microchip and DS18S20 or DS18B20 temperature sensor. The hardware part is very simple because it only uses pic microcontroller, the DS18S20/DS18B20 sensor, 4x7 segments (common anode, something like KW4-301xxx Series, or common cathode something like CC56-21SURKWA), four transistors, some rezistors!

read more "Circuit Electronic Circuit PIC16f628a Clock Schematics"

Circuit Electronic Circuit NJM2035 Stereo Encoder Schematics

NJM2035 Stereo Encoder Board

This package comes with components and instructions that are needed to build simple but high quality stereo encoder.

The circuit connects to any mono FM transmitter and converts it into HI-FI stereo transmitter. The project can be supplied with as little as 1.2 Volts, up to 3.6 Volts. The circuit also has built-in stereo pre-emphasis to enhance and produce a crystal clear sound. NJM2035 is manufactured by NJR CORPORATION (JRC), a subsidiary of New Japan Radio, a company that is known as the world's best manufacturer of high end professional audio semiconductors.

he stereo encoder consists of three main stages; pre-emphasis, digital encoder and mixer stages.Pre-emphasis stage is achieved by using two 47K resistors and two 1nF capacitors. This helps to eliminate the noise that is produced during the FM transmission of your audio signal.

NJM2035 Stereo Encoder Circuit

Second stage that is built around NJM2035 is a digital encoder. All of its internal blocks except for two audio amplifiers (pins 1 & 14) that act as separators are created using digital circuits. The first digital circuit is a 38KHz oscillator that is generated by using external 38KHz crystal (pin 7), 10pF capacitor (pin 6) and 100pF bypass capacitor (pin 5). Once 38KHz frequency is generated it is then buffered and divided into two 19KHz signals with a phase difference of 180 degrees. Once that is done these two frequencies are connected with two time division MPX digital alternating switchers ,one for each audio channel. Here audio channels are switched between each other with a total frequency of 38KHz. If you would be able to slow this frequency to 1Hz per second you would be able to hear that this all but a trick. During the first half of the second you would hear the left audio channel and during the second half of the second you would hear the right audio channel. Due to the fact that the channels are switched with a fast frequency of 38KHz per second our brain is unable to recognize that these channels are really switched and receives this as a continuous audio signal. At the same time another signal from the 38KHz oscillator is divided by half into 19KHz. This signal is called a PILOT tone because it will help a stereo decoder on the receiver’s part to slice the MULTIPLEX signal (mixed L and R audio channels) and separate them back into left and right audio channels.

read more "Circuit Electronic Circuit NJM2035 Stereo Encoder Schematics"

Circuit Electronic Circuit Function Generator Schematics

Function Generator Object

The High Speed Function Generator was published in the professional electronics section of the Aug 1996 issue of Electronics Australia, and has proven to be extremely popular. The kit is no longer available from any of the kit suppliers.

There is a problem with the TTL output when the generator is used on the LOW and MEDIUM frequency ranges AND the MAIN frequency adjust control is set to the lower 15% of it's range. Any significant loading on the TTL output will cause it to osscillate on the positive and negative edges. This is apparently an inherent problem with the MAX038 chip !. The only solution is to buffer the SYNC output of the MAX038 with a 74HC14 schmitt inverter. This can be mounted on a small piece of vero-board along with R10 and a bypass capacitor. Use the other 5 inverters in the package in parallel to provide a high current buffered output. Be sure to connect the supply pins of the 74HC14 directly to pins 15 and 16 of the MAX038.

Function Generator PCB

YES, those electro's are hanging over the edge of the PCB. I didn't have anything else available, and Jaycar was closed !. This one didn't have the TTL output, that was a last minute inclusion in the second prototype that was published, hence the oversight described below.

read more "Circuit Electronic Circuit Function Generator Schematics"

Circuit 6 Line Digital Wireless Systems XDS-PLUS Schematics

6 Line Digital Wireless Systems XDS-PLUS

The XDS-PLUS is a asperous agenda apparatus wireless arrangement antic abounding appearance of the XDR Series arranged into a metal anatomy stompbox receiver. The result: continued abundance acknowledgment and continued operating ambit that alone a Line 6 can accord you.

The XDS-PLUS appearance companderless technology and bifold agenda manual for the complete and feel of a absolute wire affiliation with an absurd akin of arrest aegis alone accessible from Line 6.

MelodyMusicOnline is an Authorized Line 6 Digital Wireless Dealer

Visit the Line 6 Web Site much more information

Features include:
• Dual RF Diversity (anti-jamming)
• Continental Roaming
• 200’ Operating Range
• 2009 Compliant so it’s Free from FCC & DTV Concerns
• Metal Stompbox Receiver with 1/4 Wave Detachable Antenna

SYSTEM CONTAINS:
• XDT4 Digital UHF bodypack transmitter
• XDR2 Digital UHF stompbox receiver
• Instrument cable
• 9V DC Power supply included
• Users guide and all necessary batteries

SPECIFICATIONS:
Frequency Response (± .5dB):
10 Hz – 20 kHz
Audio Dynamic Range:
Greater than 118 dB
Distortion:
0.03% THD
Compatible Channels:
Five
RF Output Power:
15mw
Operating Range:
200′ line-of-sight (may vary due to local conditions)

read more "Circuit 6 Line Digital Wireless Systems XDS-PLUS Schematics"

Circuit Wireless FM Transmitter Schematics

Wireless FM Transmitter Circuit Diagram

The wireless transmitter ambit congenital about transistor T1 (BF494) is a basal low-power variable-frequency VHF oscillator. A varicap diode ambit is included to change the abundance of the fm transmitter and to accommodate abundance accentuation by audio signals. The achievement of the oscillator is about 50 milliwatts. Transistor T2 (2N3866) forms a VHF-class A ability amplifier. It boosts the oscillator signals’ ability four to bristles times. Thus, 200-250 milliwatts of ability is generated at the beneficiary of transistor T2.

For bigger results, accumulate the ambit on a good-quality bottle adhesive lath and abode the transmitter central an aluminium case. Shield the oscillator date application an aluminium sheet.

Coil ambagious capacity are accustomed below:

• L1 – 4 turns of 20 SWG wire close wound over 8mm diameter plastic former.
• L2 – 2 turns of 24 SWG wire near top end of L1.
• (Note: No core (i.e. air core) is used for the above coils)
• L3 – 7 turns of 24 SWG wire close wound with 4mm diameter air core.
• L4 – 7 turns of 24 SWG wire-wound on a ferrite bead (as choke)

Potentiometer VR1 is acclimated to alter the axiological abundance admitting potentiometer VR2 is acclimated as ability control. For hum-free operation, accomplish the wireless fm transmitter on a 12V rechargeable array backpack of 10 x 1.2-volt Ni-Cd cells. Transistor T2 charge be army on a calefaction sink. Do not about-face on the transmitter after a analogous antenna. Adjust both trimmers (VC1 and VC2) for best manual power. Adjust potentiometer VR1 to set the axiological abundance abreast 100 MHz.

read more "Circuit Wireless FM Transmitter Schematics"

Circuit Wireless Headphones Receiver Schematics

Wireless Headphones Receiver

The wireless headphones receiver presented is an accepted appliance of ZN415 produced by Ferranti ( abbreviate beachcomber receiver). ZN415 assures a affection reproduction, has a 1.5 array alimentation and contains a MA detector and audio amplifier.

The accepted burning is < 5mA, L1 has 40 turns, 0.2 Ø chestnut and 20mm Ø ferrite. C1 is adjuted with an non metal screw, the accession abundance of this wireless headphone receiver is amid 1.7MHz and 3.4MHz – shortwave receiver. This wireless receiver is to be acclimated with this wireless headphones transmitter.

read more "Circuit Wireless Headphones Receiver Schematics"

Circuit Wireless headphones transmitter circuit Schematics

Wireless headphones transmitter circuit

This wireless headphones transmitter assures a affection accession over 2 meters. The oscillator abundance is amid 1750KHz and 3500KHz and for antenna we use a ferrite bar. IC1 amplifies the audio arresting and TC1 is a buffer. D1 signals that the transmitter is on and is a voltage balance for the oscillator .

L1 is a toroidal amount T50-2 with 80 turns, 0.2mm Ø. L2 requires a 10-20cm ferrite bar, L2a has 3 turns, 0.6mm Ø coiled at arena end of L2b wich has 30 turns, 0.5mm Ø .

The accepted burning of the wireless transmitter is <= 150mA and is to be acclimated with this wireless headphones receiver.

read more "Circuit Wireless headphones transmitter circuit Schematics"

Circuit Wireless Microphone circuit diagram Schematics

Wireless Microphone circuit diagram

The ambit of frequencies for the FM advertisement bandage is 90MHz (MHz = Megahertz or 90 actor cycles per second). Because the FM microphone has a capricious acquainted circuit, it can be acquainted to a quiet atom on your bounded FM advertisement bandage for the best reception. When the baby microphone aspect is addled by sound, it converts the audio to a change in accepted through resistor R1 (see schematic diagram).

This electrical change is amplified and eventually abundance modulates the transmitter. The manual ambit of the FM microphone is about 100 feet, depending on the ability of the antenna (properly acquainted or not) and the affection of the FM radio receiver.

read more "Circuit Wireless Microphone circuit diagram Schematics"

Circuit Electronic Circuit Diode Radio Schematics

Diode Radio

If you ever look at construction notes for building old detector type radios the type of headphones specified always have an impedance of 2 × 2000Ω.

Nowadays the most commonly available headphones have an impedance of 2 × 32 Ω, this relatively low value makes them unsuitable for such a design. However, with a bit of crafty transformation these headphones can be used in just such a design. To adapt them, you will need a transformer taken from a mains adapter unit, the type that has a switchable output voltage (3/4.5/6/9/12 V) without the rectifying diodes and capacitor. Using the different taps of this type of transformer it is possible to optimize the impedance match.

Diode Radio Circuit

For the diode radio (any germanium diode is suitable in this design) the key to success is correct impedance matching so that none of the received signal energy is lost. The antenna coil on the 10 mm diameter by 100 mm long ferrite rod is made up of 60 turns with a tap point at every 10 turns; this is suitable for medium wave reception. If a long external aerial is used it should be connected to a lower tap point to reduce its damping effect on the circuit. You can experiment with all the available tapping points to find the best reception. With such a simple radio design, the external aerial will have a big influence on its performance.

read more "Circuit Electronic Circuit Diode Radio Schematics"

Circuit Electronic Circuit Wire Tracer Transmitter Schematics

Wire Tracer Transmitter Object

The output frequency alternates between about 2100 Hz and 2200 Hz. This is a very distinctive test signal that is easily distinguished from any other signals that may be present.

Resistor R6 is connected to a piece of wire, about ten centimeters long, that functions as the antenna. The ground connection (junction C2-C3) is connected to ground. When the antenna is connected directly to a cable, it is possible to determine at the other end of the cable, with the aid of the receiver, which conductor is which (don’t do this with live conductors!). The schematic for the matching receiver may be found elsewhere in this website.

The circuit depicted here forms one half of a device that will prove extremely handy when tracing the path of electrical wiring in a building or to locate a break in a wire. The system is based on similar equipment that is used by technicians in telephone exchanges.

Wire Tracer Transmitter Circuit

The operation is straightforward. You require a generator that delivers an easily recognizable signal which, using a short antenna, is inductively coupled to a simple, but high gain, receiver. To create a useful transmitter it would suffice to build a simple generator based on a 555. But as the adjacent diagram shows, a 556 was selected instead. The second timer (IC1a) is used to modulate the tone produced by IC1b.

read more "Circuit Electronic Circuit Wire Tracer Transmitter Schematics"

Circuit Electronic Circuit LC Meter PIC16F628A Schematics

LC Meter PIC16F628A Kit

This is one of the most accurate and simplest LC inductance / capacitance Meters that one can find, yet one that you can easily build yourself.

This LC Meter allows to measure incredibly small inductances starting from 10nH to 1000nH, 1uH to 1000uH, 1mH to 100mH and capacitance from 0.1pF up to 900nF. LC Meter's circuit uses an auto ranging system so that way you do not need to spend time selecting ranges manually. Another neat function is reset switch that will reset the initial inductance / capacitance, making sure that the final readings of the LC Meter are as accurate as possible.

LC Meter PIC16F628A Board

Special Edition LC Meter Kit includes top notch high precision components that are only found in premium quality kits. It includes high quality printed circuit board (PCB) with green solder mask and pre-soldered tracks for easier soldering, LCD display with green LED backlight, programmed PIC16F628A microcontroller chip, high precision capacitors and inductor, 1% Metal Film resistors, Machined IC Sockets, gold plated header pins, LCD header connectors and all the other components that are needed to build a premium quality kit. Thanks to the use of LCD connectors LCD display can be detached from the main PCB board at any time even after the kit has been assembled. Special Edition Accurate LC Meter is designed for professionals that require unprecedented measurement accuracy and offers great value at low cost.

Now let's use the above theory and apply it to electronics. The LC Meter uses a popular LM311 IC that that functions as a frequency generator and this is exactly what we need. If we want to calculate the value of an unknown inductor we use a known Ccal 1000pF capacitor and the value of an unknown inductor. LM311 will generate a frequency that we can measure with a frequency meter. Once we have this information we can use the frequency formula to calculate the inductance.

The same thing can be done for calculating the value of a unknown capacitor. This time we don't know the value a capacitor so instead we use the value of a known inductor to calculate the frequency. Once we have that information we apply the formula to determine the capacitance.

LC Meter PIC16F628A Circuit

All this sounds great, however if we want to determine the value of a lot of inductors / capacitors then this may become a very time consuming process. Sure, we can write a computer program to do all these calculations, but what if we don't have an access to a computer or a frequency meter?

That's were PIC16F628A microcontroller comes handy. PIC16F628A is like a small computer that can execute HEX programs that are written using an assembly language. PIC16F628A is a very flexible microcontroller because it has PINs which can be configured as inputs and outputs. Besides that, PIC16F628A IC requires very minimal number of external components like 4.000MHz crystal / resonator and a few resistors. Before PIC16F628A microcontroller can be used it has to be programmed with a HEX code which has to be sent from the computer. All Accurate LC Meter kits already come with microcontroller that is already programmed and ready to be used.

read more "Circuit Electronic Circuit LC Meter PIC16F628A Schematics"

Circuit Electronic Circuit USB Interface Schematics

USB Interface

If the Vout of the computer or especially a laptop is not strong enough, an external power supply port can either be used to power the USB module from external. This port can also be used to power a core module by altering jumpers.

The project has the capability of connecting to the computer through USB as it provides 2 MIDI In and 2 MIDI Out ports.

USB Interface Circuit

The Cypress AN2131SC is the heart of the module which is a 8051 derivative with integrated USB peripheral. It is highly available and avoids the attachment of an external memory due to its embedded 8k SRAM. The firmware from EEPROM 24LC64 is loaded into the SRAM during power-on by the IIC bootloader. The USB firmware is open source and licensed for non-commercial use only as it is written in C. The free available EZ-USB toolchain is used to develop the code.

The USB module has only been tested with Win ME, Win XP, and Linux. Although they support the same driver which is based on the official Device Class Definition form www.usb.org , it is not guaranteed that they will work with other operating systems.

read more "Circuit Electronic Circuit USB Interface Schematics"