Lab Power Supply

Description and Circuit

Make your own lab power supply complete with adjustable voltage and constant current source.

Using single IC (LM324)

Here are the circuit.

Strip Board Layout.

Part List

1 LM324 Opamp
1 Ammeter 100 µA 1k ohm
1 Voltmeter
6 IN4001
1 Zener Diode 9.1V
1 Full-Wave Bridge Rectifier
1 LED
2 NPN Transistor, 2N3055
1 NPN Transistor, BC109C
1 Transformer
2 E-Capacitor 2200µF
1 Potentiometer 5k ohm linear
1 Potentiometer 10k ohm linear
1 Resistor 500 ohm
2 Resistor 2.2k ohm
1 Resistor 560 ohm
1 Resistor 6.2k ohm
2 Resistor 68k ohm
1 Resistor 0.22 ohm
4 Resistor 4.7k ohm

Component Image.

LM324

2N3055

Some Pictures.

 

PC IrDA interface

DIY IR interface

This circuit is also from www.electronics-lab.com. Since it is very hard for me to get the infrared interface (TFDU4100), I start to look in the old/damage handphones. It looks something like this.
 
Now, you need to remove it using the hot air blower perhaps.

Connecting to motherboard

Please refer to www.electronics-lab.com on how connect this irda module to your motherboard.

My IrDA

   

Infrared Transceiver Modules

Here are the pin layout and picture of the device.
 

Pin Description of TFDU4100

Pin Number	Function	Description	I/O	Active
1	IRED Anode	IRED anode, should be externally connected to VCC2 through a current control resistor
2	IRED Cathode	IRED cathode, internally connected to driver transistor
3	Txd	Transmit Data Input	1	High
4	Rxd	Received Data Output, open collector. No external pull–up or pull–down resistor is required (20 k. resistor internal to device). Pin is inactive during transmission.	0	Low
5	NC	Do not connect
6	VCC1/SD	Supply Voltage / Shutdown
7	SC	Sensitivity control	1	High
8	GND	Ground

Michael Jackson-Billie Jean-30th Anniversary Special

Will You Be There By Michael Jackson (Live)

Top Ten Michael Jackson Songs

Michael jackson

Top 10 Songs

Electronics Projects

Also See: Construction | Tools | Soldering | 555 timer circuits | Project books
Kits for all the projects are available from RSH Electronics.

Project kits are available! Kits for all the projects on this website are available from RSH Electronics. If you are new to electronics this is an ideal way to be sure you have the correct parts.

A brief description of the each project is given, but for full details click on the title. If you are looking for an easy project suitable for a beginner you might like to try the Flashing LED or Dummy Alarm.
The Simple Component and Continuity Tester is also very easy.
In addition to the web pages, all projects are available as PDF files to download for convenient printing onto A4 paper.
To view and print PDF files you need an Acrobat Reader which may be downloaded free for Windows, Mac, RISC OS, or UNIX/Linux computers. If you are not sure which type of computer you have it is probably Windows.
These projects are provided in good faith but no responsibilty is accepted for their accuracy or suitability for any purpose - you use them entirely at your own risk! If you find an error in a project please tell me so that I can correct it as soon as possible.

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Dummy Alarm
This project makes a superbright LED flash briefly once every 5 seconds to imitate the indicator light of a real alarm. The circuit is designed to use very little current to prolong battery life so that it can be left on permanently.This is a simple project, ideal for a beginner.

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Quiz
This project can be used for a quiz with up to 4 contestants (or teams). Each contestant has a trigger push-switch and LED. When a trigger switch is pressed it lights the corresponding LED, sounds the bleeper and prevents the other trigger switches from working - therefore showing which contestant was the first to press their switch. 

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Traffic Light
This project operates red, amber and green LEDs in the correct sequence for a single UK traffic light. The time taken for the complete red - red & amber - green - amber sequence can be varied from about 7s to about 2½ minutes. A 4017 counter is used to produce the traffic light sequence and this project could be adapted to give a different light sequence if you wish. 

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Dice
Press the push switch to 'throw' the dice: this makes the circuit rapidly cycle through the dice numbers so that an effectively random dice number is displayed by the LEDs when the push switch is released. 

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Model Lighthouse
This project was designed for a model lighthouse to flash a lamp or LED in a simple sequence: two flashes of 2s with a short gap of 1s, followed by a longer gap of 5s before repeating the sequence. A 4017 counter is used to produce the flash sequence and this project includes information on how to adapt it to give a different flash sequence. 

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Simple Component and Continuity Tester
This simple project can be used to test components, circuit board tracks, wires and connections. 

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Flashing LED
This simple project makes a good low-cost first project to check your soldering skills and learn to identify common components. The LED flashes at about 3Hz (3 flashes per second).

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Simple Electronic 'Lock'
There are six (or more) push switches. To 'unlock' you must press all the correct ones at the same time, but not press any of the cancel switches. Pressing just one cancel switch will prevent the circuit unlocking. When the circuit unlocks it actually just turns on an LED for about one second, but it is intended to be adapted to turn on a relay which could be used to switch on another circuit. Most relays cost about £2 to £3 extra.

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Adjustable Timer
This circuit starts timing when switched on. A green LED lights to show that timing is in progress. When the time period is over the green LED turns off, a red LED turns on and a bleeper sounds. The time period is set by a variable resistor and it can be adjusted from 1 to 10 minutes (approximately). It could be used to set a time limit when playing games or as an egg-timer in the kitchen.

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Light-Sensitive Alarm
The circuit detects a sudden shadow falling on a light-sensor and sounds a bleeper for a short time (adjustable). Normal lighting can be used, but the circuit will work best if a beam of light is arranged to fall on the light-sensor. Breaking this beam will then cause the bleeper to sound.

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Christmas Decoration
18 LEDs flash at three different rates and you can use these to create a decoration of your choice. A template for a Christmas tree can be downloaded. The circuit is kept simple (and low cost) by using the 4060B IC which is a counter and oscillator (clock) in one package. The circuit requires a 9V supply, such as a PP3 battery.Also see the 'Random' Flasher for 8 LEDs project.

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Model Railway Signal
This signal is controlled automatically by a passing train fitted with a magnet. It can also be manually set to red or green by pressing the switches. Trains will automatically stop at the red signal.

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Model Railway Level Crossing Lights
The level crossing warning lights are switched on automatically as a train approaches. First an amber light shows, then two red lights flash until the train has passed the crossing.

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Network Lead Tester
This was designed for confirming the continuity and correct wiring of computer network leads, but it can be adapted to check any lead with up to 8 wires by using appropriate connectors.

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'Random' Flasher for 8 LEDs
This project uses a 4026 counter and display driver IC to flash eight LEDs in an apparently random manner. It can be used to create a display of your choice.

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Heart-shaped Badge
The badge consists of eight LEDs arranged in the shape of a heart. One LED is lit at a time and this 'chases' round the shape. It would be easy to adapt this project to create other shapes with the eight LEDs. 

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Valentine Heart
18 LEDs flash at three different rates and you can use these to create an eye-catching Valentine Heart for that special person! A template for the heart shape can be downloaded. The circuit is kept simple (and low cost) by using the 4060B IC which is a counter and oscillator (clock) in one package. The circuit requires a 9V supply, such as a PP3 battery.This new project uses the same circuit as the popular Christmas Decoration.

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Kits for all these projects are available from RSH Electronics. If you are new to electronics I recommend buying a kit because it is a good way to be sure you have the correct parts for a project. 

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Touch Switch

Experiment With NAND Gate - CMOS 4011 Output goes high when touch wires bridge by finger.

Gates Oscillator

Experiment With NAND Gate - CMOS 4011

(CMOS 4011 Layout)

Circuit

Try this super-simple experiment. The output frequency is about 1kHz (square wave).

Forex 4 all

Canadian Dollar Volatility could Spur Intervention

Posted by Shehzad Khan | 11:42 AM | Canada’s Dollar | 0 comments »

The Canadian Dollar appreciated another 2% against the US Dollar, reinforcing the perception that the currency is both too volatile and appreciating too rapidly. This concern is harbored by the Central Bank officials and policymakers, which fear that the rising currency represents the proverbial wrench in the Canadian economic recovery.
From a volatility standpoint, it looks like their concerns are justified. “For years it was traditional for the cost of a one-week option on the Canadian dollar to be 20 to 25 basis points…The cost is now commonly in the 50-point to 75-point range and in the last six months it has been as high as 100 points.” On a relative basis, the currency is also more volatile than the commodities with which it is commonly associated. In the last two months alone, it recorded both a 7.4% plunge and a 10% rise. To be fair, short-term volatility is lower than it was one year ago, but this isn’t going to placate those who insist that it’s still too high.
Looking at the charge that the Canadian Dollar has risen too rapidly, this too appears valid. One could argue that the thundering 20%+ rise since March was simply a retracement (in FX terminology), necessary to offset the even bigger decline that took place following the onset of the credit crisis. This argument, however, ignores the notion that the Loonie was probably overvalued before it fell. At that time, commodity prices were sky-high, and expectations were that they would remain high, if not soar even higher. Since then, they have fallen precipitously, to less than half of the record highs recorded during the peak of the bubble.

Shehzad Khan

How to make people think you're more attractive..

Shehzad Khan: Electronic Projects

Shehzad Khan: Electronic Projects

Electronic Projects

A microcontroller (also microcontroller unit, MCU or µC) is a small computer on a singleintegrated circuit consisting of a relatively simple CPU combined with support functions such as acrystal oscillator, timers, watchdog timer, serial and analog I/O etc. Program memory in the form ofNOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for small or dedicated applications. Thus, in contrast to themicroprocessors used in personal computers and other high-performance or general purpose applications, simplicity is emphasized. Some microcontrollers may operate at clock ratefrequencies as low as 4 kHz, as this is adequate for many typical applications, enabling low power consumption (milliwatts or microwatts). They will generally have the ability to retain functionality while waiting for an event such as a button press or other interrupt; power consumption while sleeping (CPU clock and most peripherals off) may be just nanowatts, making many of them well suited for long lasting battery applications. Other microcontrollers may serve performance-critical roles, where they may need to act more like a digital signal processor (DSP), with higher clock speeds and power consumption.