Schematic Volt: a

Showing posts with label a. Show all posts

Showing posts with label a. Show all posts

Tuesday, November 18, 2014

Make a series letters from the LED

Make a series letters from the LED , Things to consider before making the sign of the LED array,
1) Use LED nodes.
2) Paint the top of the PCB with a dark color (black).
3) Note the LED specifications. In this experiment use a 5mm diameter LED nodes
that emit red, specification voltage of 3 volts.

The assembly of LED:
1) One letter composed at most 5 columns and 7 rows.
2) One column mostly composed by 6 LEDs are arranged series.
3) Then the fifth column are connected in parallel.

4) Each column given the constraints, Rx, which amount depends on the number of LEDs in one column and depends also on the type of LED (in this experiment that used LED 5mm in diameter, clear with red light beam).

5) In a column consisting of 6 LEDs, Rx = 330 ohm, 5 LEDs, Rx = 560 Ohms, 4 LEDs, Rx = 680 Ohms

Remember, this provision applies to 5 mm LED red light beam nodes.

6) Every letter was given FCS9013 transistor amplifier.

Here is one letter LED scheme.

Make

Medium picture below is the lay out of the 2-letter nameplate. To make the sign 8 letter, copied from a second stay this letter.

Make

Example of LED on the letters A and B:

Make

Value Rx in the first and the fifth column (letter A) of 560 ohms, because it consists of 5 LEDs are arranged series. Rx in the second column, third, and fourth, amounting to 680 ohms because it consists of two LEDs.

Rx first column letter B, 330 ohms. Rx second column, third, fourth, and fifth at 680 ohms.

Friday, November 7, 2014

10 to 14W Class A Audio Amplifier

I have built this amplifier and it does sound good. It requires a preamp as it hasnt got much gain. It requires big heat sinks and a large transformer and a great power supply and careful wiring, but in the end it is xtremely simple and it sounds very good. The zener diode rejects any ripple coming from the power supply, But you still only want a ripple of 10mV max. The ripple reaching the input is amplified, so the zener diode gets rid of that, but whatever ripple there is will still reach the power stage.

Tuesday, November 4, 2014

How to Build a Electronic Telephone Ringer

How to Build a Electronic Telephone Ringer. This circuit produces a ringing sound similar to that made by more recent telephones. It consists of three almost identical oscillators connected in a chain, each generating a squarewave signal. The frequency of each oscillator depends on the RC combination: R4 and C1 around IC1.A, R8 and C2 around IC1.B and R12 and C3 around IC3.C.

The pairs of 100 kΩresistors divide the asym-metric power supply voltage (between 5 V and 30 V) so that, in conjunction with the 100 kΩfeedback resistors (R3, R7 and R11) either one third or two thirds of the supply voltage will be present at the non-inverting inputs to the opamps. The voltage across the capacitor therefore oscillates in a triangle wave between these two values.

Electronic Telephone Ringer Circuit Diagram:

The first oscillator is free-running at a frequency of approximately 1/3 Hz. Only when its output is high, and D1 stops conducting, can the second oscillator run. The frequency of the second oscillator is about 13 Hz, and optional LED D3 flashes when it is running. When the output of the second oscillator is low, the third is allowed to run. The frequency of the third oscillator is around 1 kHz, and this is the tone that is produced. The second oscillator is not absolutely necessary:

its function is just to add a little modulation to the 1 kHz tone. A piezo sounder is connected to the output of the third oscillator to convert the electrical signal into an acoustic one. The current consumption of the circuit is just under 1 mA with a 5V power supply, rising to about 1.65 mA with a supply volt-age of 15 V.

Saturday, October 25, 2014

Make a Photodiode Alarm

This Photodiode based Alarm can be used to give a warning alarm when someone passes through a protected area. The circuit is kept standby through a laser beam or IR beam focused on to the Photodiode. When the beam path breaks, alarm will be triggered.

The circuit uses a PN Photodiode in the reverse bias mode to detect light intensity. In the presence of Laser / IR rays, the Photodiode conducts and provides base bias to T1. The NPN transistor T1 conducts and takes the reset pin 4 of IC1 to ground potential. IC1 is wired as an Astable oscillator using the components R3, VR1 and C3. The Astable operates only when its resent pin becomes high. When the Laser / IR beam breaks, current thorough the Photodiode ceases and T1 turns off. The collector voltage of T1 then goes high and enables IC1. The output pulses from IC1 drives the speaker and alarm tone will be generated.

Photo-Diode Alarm Circuit

Circuit Project: Photodiode Alarm circuit

IR Transmitter Circuit

Circuit Project: Photodiode Alarm circuit

A simple IR transmitter circuit is given which uses Continuous IR rays. The transmitter can emit IR rays up to 5 meters if the IR LEDs are enclosed in black tubes. Link

Thursday, October 23, 2014

Build a Converter VGA to BNC Adapter

There are monitors which only have three BNC inputs and which use composite synchronization (‘sync on green’). This circuit has been designed with these types of monitor in mind. As can be seen, the circuit has been kept very simple, but it still gives a reasonable performance. The principle of operation is very straightforward. The RGB signals from the VGA connector are fed to three BNC connectors via AC-coupling capacitors. These have been added to stop any direct current from entering the VGA card. A pull-up resistor on the green output provides a DC offset, while a transistor (a BS170 MOSFET) can switch this output to ground. It is possible to get synchronisation problems when the display is extremely bright, with a maximum green component.

In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.

VGA to BNC adapter PCB layout

This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity. LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.

Resistors:

R1,R2,R3 = 470Ω

R4 = 100Ω

R5 = 3kΩ3

Capacitors:

C1,C3,C5 = 47µF 25V radial

C2,C4,C6,C7,C10 = 100nF ceramic

C8 = 4µF7 63V radial

C9 = 100µF 25V radial

Semiconductors:

D1 = LED, high-efficiency

D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05

Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω

Build a Solar power supply

Here is Solar power supply circuit delivers either 4.8 or 7.2 V regulated at 15 mA with a 3-V input from a bank of photocells. Rl should be 453 kQ for a 7.2-V output and 274 РЁ for a 4.8-Vdc output. Regulator efficiency is around 70%. This should be considered when selecting suitable solar cells.

Circuit Diagram

Build a Solar power supply

Hi Fi 25W Power Amplifier Class A

Hi-Fi 25W Power Amplifier (Class-A) Schematics Circuit

Hi-Fi

Click to view larger

Wednesday, October 22, 2014

How to Make a Frequency Generator

How to Make a Frequency Generator. On cloud busters Fredbuster created a wonder tutorial for getting started and building your own Zapper. Fredbusters Tutorial in PDF-Based off his design here is how I made my frequency generator.

Frequency Generator Circuit Diagram

Parts Needed

1 Project box with PC board included,

1 Compositor 1 micro farad, C2, I like the un-polarized because it allows you not to worry about positive an negative sides. If you do get one with a longer leg thats the positive, see schematic for proper placement.

1 Compositor .01 micro farad, C1

1 LED 1-3 volt, small red ones. Remember the longer leg is the positive, connect properly,

1 Resistor 3.3k ohm, R1, It will say it on the upper part figuring out the colors is a pain. See photo below for product ID.

1 Resistor 3.9k ohm R4

1 Resistor 4.7k ohm R5

1 Resistor 1k ohm R3 for creating a body zapper with pennies,

1 resistor for R2 see Fredbusters PDF file for specific resistor for frequency. I use variable potentiometers because I like to set exact frequencies myself. I use 100k potentiometers, they give me a range from 6hz to 460hz when adjusting. You can see in the below photo I have both the large audio and micro potentiometers. The micro is used to be set at 15hz and the Audio is for creating variable.

1 on/off switch for the battery

1 toggle switch for the switching between 15hzand variable. Thats how I like to do mine.

1 555CN timer chip, make sure its the one that can handle up to 18 volts. The CMOS 555 can only handle low voltage and is easily shorted out.

1 8 pin IC Socket, just incase you burn out your 555 you can replace it without creating another circuit.

2 9 volt battery plugs, I like 2 because it lasts longer and has more amperage. One will do fin though.

Black and Red 22 gauge connecting wire, Make sure its the one with multiple threads of copper and not a solid one. Its easier to bend and move. The solid copper connecting wire is to kinky and breaks to easily, for my taste.

1 spool of Solder, The thinner the better, for getting into tight spaces and heats up better.

1 Solder Iron, A pin point will be needed for this circuit.

1 1/8" audio phone jack, I like them because they make the box look clean and its and easy size to attach to any other devices.

First we take the PC board that was included with the Black box and break it into a size we need.

Next we place the 8 pin bracket in the middle.

Notice on the back how I bend over the pins to hold it in place.

Next we attach R1 3.3k resistor. One end goes to pin 8 and the other to pin 7, I bend the legs over the pin then cut off 1/4" longer than the distance to the pin. the remaining 1/4" I bent over and stick in the pin hole. see schematic.

Here is how it looks on the back.

Next we attach Compositor C2 1.0 mf, and Compositor C1 0.001 mf. C2 connects to pin 6 and the base of C1. C1 connects to pin 5 and C2 base.

Here is how it looks on the back, notice how the base of C1 and C2 are twisted together.

Next we add R4 3.9k and R5 4.7k to the board.

Notice on the back the ends are twisted together and connected to Pin 3.

Here is when I added the 555 timer, make sure the black dot is in the upper left corner.

Using one of the wire ends I cut off from the excess of the resistors I connect Pin 2 to Pin 6. like so.

Now is when I start adding the wires to hook up the positive and negative connections.

Back of circuit.

Now for the wires that hook up to LED, Output jack and switches.

You can see how I soldered the connections together. Make sure you are clean and accurate. Other wise a lose connection or overlapping solder will cause the circuit not to work. This takes patients and time, dont rush it. If you do overlap a connection with solder, heat it up, use another wire to suck up the excess and then use a knife to remove the last bits. I heat the wires first then add the solder. Its cleaner once you get used to soldering. Takes practice.

Here is what the final circuit looks like before its place in a box. You can see the R2 I added here. I use a toggle switch to go back and forth between the set resistor and variable resistor. One end of the resistor is connected to R1 where it attaches to pin 7. The middle Pin on the Potentiometer is then connected to a toggle switch. The Middle switch pin is then connected to C2 where it attaches to pin 6. Using potentiometers allows you to set a frequency you want. In Fredbusterstutorial he gives you the specific resistor for specific frequency.

Here are links to four photos showing detailed enlargement of the circuit with the variable potentiometers added and how they are connected. This should explain how I connected the potentiometers.

http://www.ryanmcginty.com/orgone/frontcircuitlg.jpg

http://www.ryanmcginty.com/orgone/backcircuitlg.jpg

http://www.ryanmcginty.com/orgone/beforeboxback.jpg

http://www.ryanmcginty.com/orgone/beforebox.jpg

Next I begin placing the circuit into the box. I slip the LED wires thru to the outside because thats how you hook up this specific light. I used shrink tubing to seal the connection keeping them not from touching other wires.

You can see how I drilled the holes to fit each switch, LED and output jack. This is how I have the circuit placed inside the box. Notice the blank area to hold the two 9 volt batteries. I prefer two 9v because it allow the Freq Gen to run longer. About 14 days nonstop at 15hz.

And finally how the frequency box looks when finished. Notice I dont have penny electrodes because this box is only to power OR devices and not kill body parasites. Copy the circuit drawing above and you can have both.

Radioshack sells a digital voltage meter which has a setting for frequencies. It cost me about $50. It works great. All I do is connect the output from the generator to the meter’s input wires. Instantly it says the exact frequency the dial is tuned too. If you don’t have voltage meter and work around the house repairing things yourself this is a must have.

To put the set the frequencies I use my computer. I use the 1/8" stereo jack into my sound card, making sure the input volume is on low. Use a Sound generator program and match the tones. Make sure the sound wave is set to square. It takes time to get it right but it works.

On a good day it takes me 1 hour and half to make the whole thing. It will cost you about $40 to 45 in parts to make one like mine.

Sourced By: Ryan

Build a 3000W Stereo Power Amplifier Circuit Diagram

How to Build a 3000W Stereo Power Amplifier Circuit Diagram? Lets start first we define 3000wstereo power amplifier circuit diagram this circuit has a power output of up to 1500W RMS power amplifier circuit is often used to power sound systems spelunker for outdor. In the final image can be seen a series of power amplifiers using 10 sets of power transistors for the ending.

This power amplifier circuit using a transistor amplifier from the front, signal splitter, driver and power amplifier. Current consumption required is quite large power amplifier that is 15-20 A 1500W power amplifier circuits for this. Supply voltage needed by the power of this amplifier is the optimal working order symmetrical 130VDC (130VDC-130VDC ground). 1500W amplifier circuit below is a picture series of mono, stereo if you want to make it necessary to make two copies of the circuit. For more details can be viewed directly image the following 1500W power amplifier circuit.

The series of High Power Amplifier 1500W With Transistor

3000W Stereo Power Amplifier Circuit Diagram

In the above series of power amplifier 1500W is equipped to control a DC Offset function to set the power amplifier is turned on at the moment and with no input signal then the output should be 0VDC. Then also equipped with a flow regulator to the power amplifier bias. Final part of this power amplifier requires adequate cooling to absorb the heat generated. Power amplifier is not equipped with a speaker protector, therefore it is necessary diapsang protector on the speaker output so that when the power amplifier is not the case turned on the beat to the speaker that can damage the speaker.

Monday, October 20, 2014

Build a Single Chip FM Radio Circuit Diagram Using IC TDA 7000

To day i share cheapest cost FM radio circuit using IC TDA 7000. This Single Chip FM Radio Circuit Diagram is designed as per the data sheet and the result is excellent. Ideal for all category of electronic enthusiasts.

The TDA7000 is a monolithic integrated circuit for mono FM portable radios, where a minimum on peripheral components is crucial. The IC TDA 7000 has a Frequency-Locked-Loop system with an intermediate frequency of 70 kHz. The intermediate frequency selectivity is achieved by active RC filters. The only function which needs alignment is the resonant circuit for the oscillator, thus selecting the reception frequency. Spurious reception is avoided by means of a mute circuit, which also eliminates too noisy input signals. Special steps are taken to meet the radiation requirements.

Single Chip FM Radio Circuit Diagram Using IC TDA 7000

Single Chip FM Radio Circuit Diagram Using IC TDA 7000

Notes

For L1 and L2 wind 5 turns of 0.6 mm enameled Copper wire on a 4 mm dia plastic former.
For antenna use a 50mm long insulated copper wire.
IC TDA 7000 can withstand up to 10 V supply voltage.But I recommend 6V.
Use an 8 Ohm speaker or Headphone at the audio output.

Sunday, October 5, 2014

How to calculate the value of a resistor using the color coded stripes on the resisto

To calculate the value of a resistor using the color coded stripes on the resistor, use the following procedure.

Step One: Turn the resistor so that the gold or silver stripe is at the right end of the resistor.

Step Two: Look at the color of the first two stripes on the left end. These correspond to the first two digits of the resistor value. Use the table given below to determine the first two digits.

Step Three: Look at the third stripe from the left. This corresponds to a multiplication value. Find the value using the table below.

Step Four: Multiply the two digit number from step two by the number from step three. This is the value of the resistor n ohms. The fourth stripe indicates the accuracy of the resistor. A gold stripe means the value of the resistor may vary by 5% from the value given by the stripes.

Resistor Color Codes (with gold or silver strip on right end)

Follow the above procedure with the examples below and soon you will be able to quickly determine the value of a resistor by just a glance at the color coded stripes.

Examples

Example1:
You are given a resistor whose stripes are colored from left to right as brown, black, orange, gold. Find the resistance value.

Step One: The gold stripe is on the right so go to Step Two.

Step Two: The first stripe is brown which has a value of 1. The second stripe is black which has a value of 0. Therefore the first two digits of the resistance value are 10.

Step Three: The third stripe is orange which means x 1,000.

Step Four: The value of the resistance is found as 10 x 1000 = 10,000 ohms (10 kilohms = 10 kohms).

The gold stripe means the actual value of the resistor mar vary by 5% meaning the actual value will be somewhere between 9,500 ohms and 10,500 ohms. (Since 5% of 10,000 = 0.05 x 10,000 = 500)

Example2:
You are given a resistor whose stripes are colored from left to right as orange, orange, brown, silver. Find the resistance value.

Step One: The silver stripe is on the right so go to Step Two.

Step Two: The first stripe is orange which has a value of 3. The second stripe is orange which has a value of 3. Therefore the first two digits of the resistance value are 33.

Step Three: The third stripe is brown which means x 10.

Step Four: The value of the resistance is found as 33 x 10 = 330 ohms.

The silver stripe means the actual value of the resistor mar vary by 10% meaning the actual value will be between 297 ohms and 363 ohms. (Since 10% of 330 = 0.10 x 330 = 33)

Example3:
You are given a resistor whose stripes are colored from left to right as blue, gray, red, gold. Find the resistance value.

Step One: The gold stripe is on the right so go to Step Two.

Step Two: The first stripe is blue which has a value of 6. The second stripe is gray which has a value of 8. Therefore the first two digits of the resistance value are 68.

Step Three: The third stripe is red which means x 100.

Step Four: The value of the resistance is found as 68 x 100 = 6800 ohms (6.8 kilohms = 6.8 kohms).

The gold stripe means the actual value of the resistor mar vary by 5% meaning the actual value will be somewhere between 6,460 ohms and 7,140 ohms. (Since 5% of 6,800 = 0.05 x 6,800 = 340)

Example 4:
You are given a resistor whose stripes are colored from left to right as green, brown, black, gold. Find the resistance value.

Step One: The gold stripe is on the right so go to Step Two.

Step Two: The first stripe is green which has a value of 5. The second stripe is brown which has a value of 1. Therefore the first two digits of the resistance value are 51.

Step Three: The third stripe is black which means x 1.

Step Four: The value of the resistance is found as 51 x 1 = 51 ohms.

The gold stripe means the actual value of the resistor mar vary by 5% meaning the actual value will be somewhere between 48.45 ohms and 53.55 ohms. (Since 5% of 51 = 0.05 x 51 = 2.55)

Other Resistor Information

There are some more rules that may be useful when working with resistors. You do not need to know them but if you need a resistor with a value that you do not have, you my be able to use the following information to create the value of resistor you need.

First Rule for Resistors : Series Connection

When two resistors are connected in series, as shown in Figure 1, the new resistance between points A and B is R1 + R2.

Figure 1

The resistors add together. For example if R1 = 500 ohms and R2 = 250 ohms then the resistance between points A and B would be R1 + R2 = 500 + 250 = 750 ohms.

Second Rule for Resistors : Parallel Connection

When two resistors are connected in parallel, as shown in Figure 2, the new resistance is smaller than either R1 or R2. The new resistance between points A and B is (R1 x R2) / (R1 + R2).

Figure 2

For example, if R1 = 500 and R2 = 250 then the resistance between points A and B = (500 x 250) / (500 + 250) = (125,000) / (750) = 167 ohms. If R1 = R2 then the new resistance is just R1 / 2.

Saturday, September 13, 2014

Class A headphone amplifier

Class A headphone amplifier

Class A headphone amplifier

Thursday, September 4, 2014

Build a Freezer Meltdown Alarm Wiring diagram Schematic

How to Build a Freezer Meltdown Alarm Circuit Diagram? Thats easy or nothing ? This is a simplest schema, This is a schema diagram. The meltdown is a magnet held to a small stand by ice. A reed switch is below the magnet. When the ice melts, the magnet falls on the switch, closing it, and completing the alarm schema.

Freezer Meltdown Alarm Circuit Diagram

Freezer

Thursday, August 28, 2014

Build a Telephone Conversation Recorder Wiring diagram Schematic

Build a Telephone Conversation Recorder Circuit Diagram. This Telephone Conversation Recorder Circuit Diagram enables automatic switching-on of the tape recorder when the handset is lifted. The tape recorder gets switched off when the handset is replaced. The signals are suitably attenuated to a level at which they can be recorded using the ‘MICIN’ socket of the tape recorder. Points X and Y in the schema are connected to the telephone lines.

Resistors R1 and R2 act as a voltage divider. The voltage appearing across R2 is fed to the ‘MIC-IN’ socket of the tape recorder. The values of R1 and R2 may be changed depending on the input impedance of the tape recorder’s ‘MIC-IN’ terminals. Capacitor C1 is used for blocking the flow of DC. The second part of the schema controls relay RL1, which is used to switch on/off the tape recorder.

Telephone Conversation Recorder Circuit Diagram

Telephone

A voltage of 48 volts appears across the telephone lines in on-hook condition. This voltage drops to about 9 volts when the handset is lifted. Diodes D1 through D4 constitute a bridge rectifier/polarity guard. This ensures that transistor T1 gets voltage of proper polarity, irrespective of the polarity of the telephone lines.

Tuesday, August 26, 2014

Build a Low Power Consumption 5V Regulator Wiring diagram Schematic

How to build a Low Power Consumption 5V Regulator Circuit Diagram? The special feature of the schema shown below is the low consumption. With voltage n 9 at the entrance and no exit load, absorbs current 50 ma, which is certainly very small compared with a quiescent current 78L05. The components that comprise it are scarce. Just a reference voltage source, formed by the T1 and the IC 1 and an amplifier consisting of the IC2 and T2 so we have to output the desired voltage stabilizer.

The trend that emerges at the output of IC 1 increased to 1,22 V. Using the IC2 and the P1 is set so that the output of the schema is n equal to 5 exactly at the entrance of the schema can be imposed voltage between 6.5 ??? 30 V DC, while the maximum output current reaches 1 mA for the better functioning of the stabilizer, transistors T and T 1 a 1 b should be possible similar characteristics. That is why we preferred a double type transistors MAT02 or alternatively one of the MAT01, SSM2210 or LM394.

Low Power Consumption 5V Regulator Circuit Diagram

Low

If your course is hard to find, you can use two common BC, but which should be selected to have approximately the same threshold voltage. The Operational IC 1 and IC2 is type OR22. Especially for IC2, the peak current of the output can be set using the power introduced in this through the resistor R9. The price of electricity varies between 500 to 400 ma BAC course, before making an increase, you should check whether the output transistor T2 is able to meet the equally elevated currents that it may request the load.

The filter formed by the R6-C 1 is meant to suppress the spurious peaks may accidentally be deployed at the entrance of IC2. The capacitor C2 improves the stability of the schema, wherethose which the stabilizer is required to provide pulsed current. The total schema resistance and is highly therefore sensitive to any kind of electrostatic and magnetic disturbances. The control stabilizer made with a complex load to absorb continuous stream of 1 mA. The pulse of 1 mA Measurement results are shown in the table. The current Ig represents the quiescent current of stabilizer.

Monday, August 25, 2014

Build a 4 Transistor FM Transmitter Wiring diagram Schematic

4 Transistor FM Transmitter Circuit Diagram

4 transistor fm transmitter circuit diagram

Build a 4 Transistor FM Transmitter Circuit Diagram. This 4 Transistor FM Transmitter Circuit Diagram provides an FM modulated signal with an output power of around 500mW. The input microphone pre-amp is built around a couple of 2N3904 transistors (Q1/Q2), and audio gain is limited by the 5k preset trim potentiometer.

The oscillator is a colpitt stage, frequency of oscillation governed by the tank schema made from two 5pF ceramic capacitors and the L2 inductor. The output stage operates as a Class D amplifier, no direct bias is applied but the RF signal developed across the 3.9uH inductor is sufficient to drive this stage. The emitter resistor and 1k base resistor prevent instability and thermal runaway in this stage.

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