Advance Oatley Electronics K295 Stereo Tube Sound Line Buffer Amplifier Kit

Oatley Electronics K295 Stereo Tube Sound Line Buffer Amplifier Kit


The latest kit offering from Oatley Electronics is the K295 Stereo Tube Sound Line Buffer Amplifier Kit which retails for $36AU. The low cost, simple to construct, stereo tube buffer, lets you experience "tube sound". The kit is based around JAN 6418 sub-miniature vacuum tubes and designed for 100-120 or 200-240V 50/60Hz AC operation. These inexpensive tube kits can sound quite good, see Mark's review of the K272 Headphone Amplifier Kit and the recent review in audioXpress. Via - Mark [K295 stereo JAN6418 tube buffer / preamp kit].

Construction and Parts List for VHF/UHF TV modulator

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The circuit diagram- figure 2

Construction

The tiny printed circuit board designed for this circuit is shown in figure 3. It is not double-sided as this was found to be unnecessary. Construction is thereby simplified and readers who do not buy the board through our EPS service (tut-tut) will find it easier to make themselves. Building the circuit is simply a matter of fitting the components onto the printed circuit board. The coils, often a source of much teeth-gnashing and hair-pulling, will not be a problem in this case. Two of them, Ll and L2, are made by winding 3.5 turns of enamelled copper wire (about 0.2 mm thick) on a 3.5 mm ferrite bead. Another, L4, is just one turn of copper wire (0.8. . . 1 mm thick) air-wound with a diameter of 8 mm. The fourth inductor, L3, can simply be bought. Any third overtone crystal with a frequency of between 25 and 30 MHz will work in this circuit. A number of suitable values are advertised in this issue. The only parts that might prove difficult to find are diodes Dl and D2. The ones stated in the parts list are available at the moment but do not give up hope if your corner shop does not have them. The only important thing is that they must be UHF Schottky diodes; the actual type number is of little consequence.

Parts list

Resistors:
R1, R2 = 4k7
R3, R4 = 56ohm
P1 = 100 ohm preset
P2 = 500 ohm preset

Capacitors:
C1 = 4mf7/16 V
C2= 10p
C3 = 220p
C4 = 47p
C5 = 47n, ceramic
C6 = 100n*
C7 = 330n*

Inductors:
L1, L2 = 3.5 turns of 0.2 mm (SWG 35 or 36) CuL on a ferrite bead of about 3.5 x 3.5 mm
L3 = 1 microH
L4 = 1 turn of 0.8. . .1 mm (SWG 19...21) CuL, air wound with a diameter of 8 mm

Semiconductors:
D1, D2 = 1N6263 (Ambit/Cirkit)
D3 = lN4148
T1 = BFR91 (Ambit/Cirkit)
IC1 = 7805*

Miscellaneous:
X1 = crystal, 27 MHzd(3rd overtone) or other 3rd overtone crystal between 25 and 30 MHz

*= not needed if the circuit is powered from a stabilised 5 V supply

88-108 MHz Mono Modulated Fm Transmitter Circuit for House

This is a Fm Transmitter circuit for house.It
is a mono modulation type FM and Frequency range 88-108 MHz. Working voltage range 12-18 VDC and use current max at 450mA only. This circuit convenient for , because , have good small-sized. It is the ideal project for the beginner who wishes to get started in the fascinating world of FM broadcasting and wants a good basic circuit. This circuit use the transistor the important , be the number is 2N3553.

Lower Sensitivity Pocket FM Radio BF184

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The idea was to use a simple receiver, but can be used to escape to 3 times viewed. My previous 6-transistor receiver was more complicated and requires 12 volts. This means that 10 AA batteries. I designed and built acircuit board, and built a small aluminum box will hold Comact as possible.

There is nothing wrong with this design. The detector has a simple Colpitts oscillator is of a type often used in other receptor super-regeneration. It’s natural for yourself. The sensitivity for this type of detector is relatively low, but it’s simple and easy to get work. As always, gave me a feedback control to determine the optimum point of operation, ie. maximum sensitivity and minimum SCA / stereo subcarrier beat.

REF:www.stardi.com/simple-fm-receiver-pocket-fm-radio-circuit-main-bf184-transistor/

Mosfet 1000 Watt Inverter Produsing Stable “Square Wave” Output Voltage.


Explaination:

This power inverter circuit will provide a very
stable “Square Wave” Output Voltage. Frequency of operation is determined by a pot and is normally set to 60 Hz. Various “off the shelf” transformers can be used. Or Custom wind your own for best results.

Additional MosFets can be paralleled for higher power. It is recommended to Have a “Fuse” in the Power Line and to always have a “Load connected”, while power is being applied. The Fuse should be rated at 32 volts and should be aproximately 10 Amps per 100 watts of output. The Power leads must be heavy enough wire to handle this High Current Draw! appropriate Heat Sinks Should be used on the RFP50N06 Fets. These Fets are rated at 50 Amps and 60 Volts. Other types of Mosfets can be substituted if you wish.

There ARE Limitations! I have had numerous requests for an Inverter for 1000 watts and Even MORE. Sorry I Don’t feel this is Practical. At 1000 Watts and operating from a 12 Volt Source, the Input Current will be close to 100 AMPS. That would Require a HUGH Size of a Primary Wire.

No Power Supply Requires to Operate for Emergency Crystal Radio

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Crystal Radio

Emergency Crystal radio
requires no power supply to operate because it uses energy from the signals it receives. Performance is – like one should expect – poor. Nevertheless, with a good antenna and proper ground, it shouldn’t be too difficult to tune to a strong AM station.



While this emergency crystal radio circuit is very simple, many points should be observed. The variable capacitor is relatively hard to get in a store these days, so your best bet to find one could be a junked AM receiver. Connect the case to the antenna and the central rod to ground. Otherwise, you’ll de-tune the circuit every time you touch the capacitor.

Next comes the coil. Originally, 60-80 turn air core coils of large diameter (10cm) were used. A less bulky alternative could be 30 turns of enamel-coated magnet wire wound on a ferrite rod. It works for me, at least.

Detection and demodulation of the signal is done by a germanium diode. In the US, 1N34 seems to be very popular. Here in Europe, AA119 is more common and offers similar performance.

Finally, you’ll need high-impedance headphones. These are also quite rare. Ordinary Walkman phones won’t work directly. Add an audio output transformer to drive them or build a small amplifier like shown on the next page.

Problems:
To hear anything, you’ll need a very long antenna. Use any hookup wire at least a few meters in length. Make sure that no power lines are nearby! A good ground is also vital, like a cold water pipe. Otherwise, plant a metal rod as deeply in the ground as possible and it should work well.

Possible uses:
In these times of incredible advance in technology, such a simplistic receiver doesn’t seem to have any real use at all. It’s a nice project for the more nostalgic types, though. Since no power is required for operation, having such a receiver could prove handy in an emergency situation or just to hear the news when you’re out in the woods backpacking

Analysis of a Sound to Determine at Various Frequencies Using Mini Audio Spectrum Analyzer LM3915

The circuit has been designed to create a spectrum analyzer that will provide an analysis of a sound to determine at various frequencies, the volume of sounds that make up the overall sound spectrum.
MIni Audio Spectrum Analyzer

Circuit Explanation

The device is sensitive enough to determine the sound wave components of frequency and amplitude with the changing of frequency and the width of an acoustic signal. The proportionality of signal width is indicated by the brightness of LED as it turns ON while the color indicates the proportionality of frequency. In order for the red LED to turn ON in strong signal, the sensitivity of the input circuit is adjusted by resistor R2. The middle signal is represented by a yellow LED while the low signal is indicated the green LED.
The 10 LEDs in 3 lines comprise the display unit which is ensured the IC2 as it functions as a counter decoder represented by the two gates ICa-b.the frequency of the counter is being regulated by R6. No LED will turn ON in the absence of any signal in the input. The LEDs will begin to flicker or blink depending on the intensity and tempo of the signal, once a signal has been applied in the input. The values of the resistors R4 & R5 can be varied that will be suitable for the desired requirements. Alternatively, this can be done by placing a 1K ohm trimmer in place of R4 & R5 during the initial regulation and adjustment of the values. It can be eventually removed and replaced with permanent resistors as soon as the desired values are achieved. Additional LEDs can be added in connection to IC2 although this circuit does not precisely measure the input signal.
Part List

R1= 1K8Kohm
R2= 100Kohm trimmer
R3= 1Kohm
R4= 100 ohm…..1Kohm
R5= 100 ohm…..1Kohm
R6= 100Kohm trimmer
C1= 100nF 100V
D1….10= RED LED
D11….20= YELLOW LED
D21….30= GREEN LED
IC1= LM3915
IC2= 4017
IC3= 4011
Application
This audio spectrum analyzer is a user interface component capable of making visible the sound pressure for a range of frequencies over time by taking a sample from an audio data stream and an animated visualization during the play is created in real time. It is ideal for any purpose which includes analysis and identification of human speech, ham radio audio reception tuning, analysis of vocal and instrumental music, evaluation and tuning of musical instruments, analysis of bat echolocation sounds, evaluation and calibration of home audio systems, and analysis and identification of biological sounds. Other uses of the audio spectrum analyzer are in distortion analysis, transfer functions, and digital filtering.

Isolation Step Up/Down Power Transformer(110 to 220 Converter)

If you want to 220V AC voltage from 110V AC source, then a 220 converter that is known as the step-up voltage converter needs to be applied for this purpose. It is very easy to do, just by using a step-up transformer.

The 220 converter is a power transformer. In the use of 220 converter also functions as a 110 converter, changing the voltage 110V AC to 220V AC. So an ordinary power transformer has the function of step up and step-down voltage converter.

Measuring Power Transformer Rating

In order for your 220 converter is the right choice, you need to determine wattage requirements of electronic applications that will be used to it. If your device requires 220V 1100W to work properly it needs the current 5 amperes, then the minimum current required 10 amperes at 110V input voltage.

Because of the current in the transformer is influenced by the diameter of the wire coils used in secondary and primary winding transformer. The greater the wattage you need, the greater the form of the transformer stepped up / down.

Measurement of Surface Temperature By Using Infrared Radiometer

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Measurement of surface temperature is a crucial component of energy transfer. Accurate measurement of the leaf-to-air temperature gradient is essential to the determination of transpiration rate and stomatal conductance in both single leaves and plant canopies.

This gradient is often less than 1 C, which means that leaf temperature should be measured to within 0.2 C. To achieve this accuracy, the Apogee Instruments Infrared Radiometers correct for changes in the sensor body temperature with a subroutine designed for Campbell Scientific dataloggers.


Design for ECC802S Tube SRPP Preamplifier

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ECC802S Tube SRPP Preamplifier

Bruce of OddWatt Audio has shared with us his ECC802S tube SRPP preamplifier design. The preamplifier uses a solid state power supply and DC is used for the heaters. The gain of the preamp can be set at 7 or 11. 12AU7 and ECC82 tubes can also be used. For more information about this project, see the DIY ECC802S (12AU7 / ECC82) Vacuum Tube SRPP Preamplifier.

Brief Configuration About Voltmeters

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About voltmeter
  • Voltmeters measure voltage.
  • Voltage is measured in volts, V.
  • Voltmeters are connected in parallel across components.
  • Voltmeters possess a extremely higher resistance

measurement with voltmeter
Connecting a voltmeter in parallel

Measuring voltage at a stage
When testing circuits you often have to find the voltages at numerous factors, for instance the voltage at pin 2 of a 555 timer chip. This can seem complicated – where should you connect the second voltmeter lead?

  • Connect the black ( damaging -) voltmeter lead to 0V, normally the negative terminal of the battery or power provide.
  • Connect the red ( constructive +) voltmeter lead to the point you exactly where you need to measure the voltage.
  • The black lead can be left completely connected to 0V whilst you use the red lead as a probe to measure voltages at numerous factors.
  • You may wish to make use of a crocodile clip around the black lead to maintain it in location.

Distinct Advantages of Infrared Thermometers Over Contact Thermometers

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Infrared thermometers offer some distinct advantages over contact thermometers, since they can measure temperature without physically touching the object. Infrared temperature measurement is ideal for measuring objects that:
  • Are too far or to difficult to reach
  • Require non-contamination from one reading to the next
  • Are moving, rotating or vibrating
  • Are too time consuming for contact sensors and require quick temperature measurements
  • Have high temperatures up to 3,000 F
  • Can be scratched or damaged by physical contact
  • Have curved, distorted or varying surface conditions
  • Are too thin and soft for contact sensors
  • Are too hot to touch or approach
  • Are electrically active and too dangerous to touch

Brief describition and Features of the Temperature Data Logger

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Here's a temperature data logger circuit, an 8-pin microcontroller based circuit for temperature data logging via the serial port of any computer from between 1 and 4 remote digital temperature sensors, DS1820/DS18S20 made by Dallas.

Features of the Temperature Data Logger are are follow:
  • Provides realtime data via the serial port.
  • Interfaces up to 4 x DS1820 sensors.
  • Accuracy to 0.5 degrees centigrade
  • Fahrenheit scale selected by a jumper
  • No external power required
  • Data stream easily logged & processed.
  • Over 200m distance for each sensor

Decorating The Sound Of Organ,Piano By Comparing with sound level tool

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A tool that use for fine to decorate the sound of , organ , piano , have the pitch is equal. By have the accuracy is similar to with compare with the sound of the professional. But use the ability in listenning sound beat. At happen between 2 frequency sounds that confute by use origin frequency pillar circuit in 250.830 kHz frequency occurrences. For feed to reach first part of 5 IC. Which build the circuit divides by the frequency model a program.

IC 8211 Used to Bright LED

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This circuit can use with power supply since 5 volt until 25 Volt. When voltage of power supply or battery agree come to lower location level keeps. It make LED bright show know. Although the circuit this use how many is the equipment not, but there is the stability and accurate in good moderately work. Because of use IC Voltage Detector 8211 that bring build be Voltage Comparator Circuit. Which have Voltage Comparator at certainly stay within the integrated circuit. Using fines to decorate VR1 give Volt tall more Voltage Comparator The a little when level Battery Volt lower LED as a result bright suddenly.

Schematic Diagram ForThree-Phase Full Wave Bridge Rectifier


A rectifier is an electrical device that converts alternating current (AC) to direct current (DC), a process known as rectification. This almost always involves the use of some device that only allows one-way flow of electrons, a diode. Above schematic diagram shows a Three-Phase Full Wave Bridge Rectifier Circuit Diagram. Each three-phase line connects between a pair of diodes: one to route power to the positive (+) side of the load, and the other to route power to the negative (-) side of the load.

An Exciting product( BA1404 HI-FI Stereo FM Transmitter Kit)

hi fi stereo fm transmitter

hi fi stereo fm transmitter

Be “On Air” with your own radio station! BA1404 based transmitter is an exciting product that will broadcast high quality stereo signal in 88MHz - 108MHz FM band. It can be connected to any type of stereo audio source such as iPod, Computer, Laptop, CD Player, Walkman, Television, Satellite Receiver, Tape Deck or other stereo system to transmit stereo sound with excellent clarity throughout your home, office, yard or camp ground.




Introduction To Lenticular Lenses With Lenticular Viewing

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After the release of some major motion pictures like Avatar, UP, Alice in Wonderland and so on, the whole movie industry has been turned on by the 3D effect. Due to this boom in the 3D movie world, major TV manufacturers have also started developing 3D TV’s for home viewing. There are mainly three basic methods that are developed to produce a 3D image on an LCD TV. But their production had been refined as some methods are more costly than the others. At the same time, the costlier ones turn out to be the more feasible ones and also user friendly.

The first thing that comes to our mind is the use of 3D glasses for viewing a 3-Dimensional movie. The use of glasses for watching movie in a TV is can be again cut down to two types of technologies namely Passive glass system and Active Glass system.

Here we are going to discuss a new type of technology where we can view 3D movies with the same effect, and that too without the use of glasses. This is called lenticular viewing.

Lenticular Viewing

This method involves the use of lenticules, which are actually very tiny cylindrical plastic lenses. These lenticules are then attached on to a transparent sheet in an array, and then stuck on to the LCD TV screen. Thus when a person views the screen, different images is received by the left and the right eye. That is, the images received by your left eye will be completely different from that received by the right eye. These different 2D images seen by your both eyes will be combined to a single 3D image by your brain. This method is actually called stereopsis, in which the eyes discern the depth).Thus, like other methods, there is no need of the use of 3D glasses for watching a movie.

The detailed figure that shows the actual working of a lenticular lens is shown below.

Lenticular Lens
Lenticular Lens

This method can be easily tried and experimented at home. All you have to do is take a magazine, roll it to a cylindrical shape and view through it with your one eye, keeping te other eye closed. First see through your right eye, then your left eye. While viewing through one eye keep the other one closed. You will notice that by viewing through different angles you are actually viewing different images. That is, from your left eye, you get to see more pictures and text that is on the extreme left side. From your right eye, you see more pictures and text that is on the extreme right side. When both these images are combined, you get a full depth image in the brain.

Disadvantages

• The developers of this technology have to create special type of images for the effect to work. The two sets of images must be joined together. Thus, if a person, views such a video in a normal LCD TV, he would only be able to see blurry double images.
• Some people may not be able to cope up with the lenticular display for long. They feel a kind of motion sickness after watching the display for a long time. This is because the eyes are given extra work to focus and also converge the image.

• This method is less popular than the other two autostereoscopic methods.

• The production of such a 3D TV will also be costly.

• For viewing images using such a technology, you are bound to sit in a “sweet spot” for getting the correct 3D effect. Even a little bend away from the angle will cause the images to be blurred. Thus only 2 or 3 people can easily watch TV comfortably due to the small angle for viewing.

• Though the above problem can be easily avoided to a certain extent by increasing the number of lenticules and also the refresh rate of the screen, the increasing expense will cause problems.



Barking Dog Alarm Circuit Working

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Condenser microphone (the alarm) mounted in the dog’s cage will perceive the sound bark and produces an AC signal, which pass through the DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 with T2 will strengthen the voice signal and provide current pulses from the collector of T2. Trigger input pulses applied to the collector of transistor T3 and combined with capacitor C3 to the base of the transistor T4, which causes the T4 Cutt-off. The collector voltage of transistor T4 forward biases transistor T3 through resistor R8.

Barking Dog Alarm Circuit

Barking Dog Alarm Circuit

Transistor T1 conducts and capacitor C3 discharges to keep transistor T4 cut-off. Transistor T4 remains cut-off until capacitor C3 charges enough to enable it to conduct. When transistor T4 conducts, its collector voltage goes low to drive transistor T3 into cut-off state. Resistor R9 and capacitor C3 are timing components. When fully charged, capacitor C3 takes about two minutes to discharge. So when sound is produced in front of the condenser mic, TRiAC1 (BT136) fires and the bulb (B1) glows for about two minutes.


LED Tester Tool Making

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The project pertains to a standalone LED test tool that can be used to avoid the hassle of complicated LED testing using LED’s datasheet, multimeter, or power supply.

Explanation

There are several factors involved when selecting an LED for a project since various shapes and colors of LED electronic components are available in the market. The actual color of the LED, current required for the desired brightness, resistor size needed to achieve the current/brightness, and choosing the anode or cathode on the LED. Since the voltage drop of the LED varies based on current, computing the resistor value is not that easy.

As a power source, a 9V battery is used by the LED tester since it does not monopolize the bench variable power supply while providing portability. A double-sided sticky tape is used to attach the 9V battery to the PCB. The battery will last for many years so scraping off the tape when it is time to replace the battery will not be a problem because the circuit only uses between 2mA and 26mA when briefly lighting an LED and does not consume any measurable power when idle.

SG3525 using DC motor Controller

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This control circuit is ideal for the accurate control of DC motors as well as other applications like lighting levels and small heaters etc. The circuit converts a DC voltage into series of pulses, such that the pulse duration is directly proportion to the value of the DC voltage. The great advantage of such a circuit is that almost no power is lost in the control circuit.

This circuit protects against overload and short circuit, PWM range can be adjusted from 0-100%, PWM frequency is 100HZ-5KHZ adjustable. Operation voltage from +8V~ 35V, minimum current consumption is about 35mA. Maximum current can go up to 6.5A. Efficiency better than 90% at full load.

The functions of three trim pots are as follow:
VR1: setting the minimum output voltage
VR3: setting the maximum output voltage
VR2: setting the output frequency.

Latest Dimmer 12 Volt Lamp

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Here is a 12 volt / 2 amp lamp dimmer that can be used to dim a standard 25 watt automobile brake or backup bulb by controlling the duty cycle of a astable 555 timer oscillator. When the wiper of the potentiometer is at the uppermost position, the capacitor will charge quickly through both 1K resistors and the diode, producing a short positive interval and long negative interval which dims the lamp to near darkness. When the potentiometer wiper is at the lowermost position, the capacitor will charge through both 1K resistors and the 50K potentiometer and discharge through the lower 1K resistor, producing a long positive interval and short negative interval which brightens the lamp to near full intensity. The duty cycle of the 200 Hz square wave can be varied from approximately 5% to 95%. The two circuits below illustrate connecting the lamp to either the positive or negative side of the supply.

From : http://ourworld.compuserve.com/homepages/Bill_Bowden/

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