Innovation & Idea

noreply@blogger.com (ayie) — Sat, 20 Feb 2010 16:24:00 +0000

Diodes are polarised, which means that they must be inserted into the PCB the correct way round.
This is because an electric current will only flow through them in one direction (like air will only flow one way through a tyre valve). Diodes have two connections, an anode and a cathode.
The cathode is always identified by a dot, ring or some other mark.

Diodes Symbols

The pcb is often marked with a + sign for the cathode end. Diodes come in all shapes and sizes.
They are often marked with a type number.
Detailed characteristics of a diode can be found by looking up the type number in a data book.

If you know how to measure resistance with a meter then test some diodes. A good one has low resistance in one direction and high in the other.

There are specialised types of diode available such as the zener and light emitting diode (LED).

Diodes Symbols

Diode Connections Tutorial

Diode Connections

The cathode end of the diode is usually marked in some manner.
Forward Biased Junction Tutorial

Forward Biased Junction Tutorial
Forward Biased Junction Tutorial

Forward Biased Junction

Bear in mind that like charges repel and unlikes attract. When a battery is connected as shown, the negative terminal pushes negative electrons towards the junction.
The positive terminal pushes holes towards the junction.
If the voltage is high enough then the barrier will be overcome and current will flow through the junction.

There is a voltage across the diode. 0.6 for silicon, o.3 for germanium.

The junction is said to be FORWARD BIASED.

The P type is the anode of the diode, the N type the cathode, as shown by the diode symbol.

The resistor limits the current to a safe level.

Transistor Lower Base Bias Resistor Open Circuit Tutorial

noreply@blogger.com (ayie) — Sat, 20 Feb 2010 16:22:00 +0000

There is no potential divider action and the full +9 volts is applied to the base by R1.

This causes a high base current to flow, which in turn causes a high collector current to flow.

There is a large volts drop across R3, causing a low collector volts.

There is a large volts drop across R4, causing the emitter volts to rise.

Tracking Stollen Laptop.

noreply@blogger.com (ayie) — Sat, 16 Jan 2010 10:48:00 +0000

How to track back your laptop when it taken by someone?

I'm using LOGMEIN. You can see if the person thar taking your laptop online or not, when your laptop was online. It also record capture ip, time & date. Its free.. try it.

Atmel AT89S51, AT89S52, AT89C51, AT89C2051

noreply@blogger.com (ayie) — Thu, 15 Oct 2009 07:35:00 +0000

HP Compaq dc7900 Small Form Factor PC driver for windows Xp

noreply@blogger.com (ayie) — Wed, 07 Oct 2009 08:35:00 +0000

Microsoft Windows XP SP2 Universal Audio Architecture Update (Q888111)

Intel Chipset Support for Microsoft Windows

NVIDIA Graphics Driver for Non-HDMI Graphics Cards (Microsoft Windows XP)

Agere (LSI) Systems Soft Modem

Intel Gigabit Network Connection Drivers for Microsoft Windows XP

Live Streaming Universiti Malaysia Pahang Konvocation

noreply@blogger.com (ayie) — Fri, 02 Oct 2009 12:28:00 +0000

Sila clik disini

Running Light LED

noreply@blogger.com (ayie) — Tue, 29 Sep 2009 04:42:00 +0000

Congratulation, you have succeded with make more LED to blink. Now lets improve your skill by making running LED ( 8 LED ). In this lesson, you'll turn on one LED in sequence for 8 LED.

Step 1st
Build the circuit as shown in figure 2.1.3. As you seen on figure 2.1.3. P0.0 trough P0.7 is connected to LED's katode each. Remember, that all we want to do with this lesson is make these LED to run.

Microcontroller Application LED

Figure 2.1.3. Diagram Skematik Running LED

Step 2nd
In this step, you must tipe the assembly program to make four LED blink, we assume that you have already known the editor, we used MIDE-51 to edit the program.

org 0h
start: mov P0,#11111110b; Turn on LED on P0.0
call delay ; call delay time
mov P0,#11111101b; Turn on LED on P0.1
call delay ; call delay time
mov P0,#11111011b; Turn on LED on P0.2
call delay ; call delay time
mov P0,#11110111b; Turn on LED on P0.3
call delay ; call delay time
mov P0,#11101111b; Turn on LED on P0.4
call delay ; call delay time
mov P0,#11011111b; Turn on LED on P0.5
call delay ; call delay time
mov P0,#10111111b; Turn on LED on P0.6
call delay ; call delay time
mov P0,#01111111b; Turn on LED on P3.7
call delay ; call delay time
sjmp start ; loooooop forever to start
;=============================================
;subroutine delay created to rise delay time
;=============================================
delay: mov R1,#255
del1: mov R2,#255
del2: djnz R2,del2
djnz R1,del1
ret
end

Step 3rd
Safe your assembly program above, and name it with LED3.asm (for example) Compile the program that you have been save by using MIDE-51, see the software instruction.

Step 4th
Download your hex file ( LED3.hex ) into the microcontroller by using Microcontroller ATMEL ISP software, see the instruction.After download this hex file you'll see the action of the LED ( of course if your cable connection and your program are corrected ).

4 Channel RF Remote Control

noreply@blogger.com (ayie) — Tue, 29 Sep 2009 00:06:00 +0000

Figure 1. RF 4 channels remote Transmitter

This is a very simple RF transmitter circuit that consists of the Holtek HT-12E encoder chip and AM 418MHZ-transmitter module (WZ-X01). Using the hybrid RF xmit/receive modules make building the RF remote control a lot easy.

The transmitter can be powered with any voltage from +3 to +12V. The total current consumption is less than 5ma. Depending on the supply voltage, you may need to select a difference resistance value for the oscillator resistor R1. The recommended oscillator is Foscd (decoder) = 50 Fosce (encoder). See data sheet for more details.

The individual security code of the transmitter is preset by dip-switches S5, up to 256 combinations.

When any of S1-S4 is pressed the /TE pin is pulled low, and power is applied to both the encoder chip and transmitter module, the encoder then starts scanning and transmitting the status of the 12bits address and data serially.

Figure 2 RF 4 channels receiver circuit

The circuit diagram for the receiver (WZ-R01)is shown in figure 2. The decoder U1(HT-12D) receives serial addresses and data from the encoder that are transmitted by the RF transmitter module. It compares the serial input data three times continuously with its local addresses. If no error or unmatched codes are found, the input data codes are then decoded and transferred to the output pins D8~D11. The VT pin also goes high to indicate a valid transmission, which will turn on the LED1. The addresses of the decoder (set by S1) have to be matched with the transmitter encoder. The outputs of U1 drive the four TIP30 PNP transistors that can be connected to the relays or lamps.

The operating range of this transmitter/receiver is dependent on the choice and position of the antenna. The space around the antenna is as important as the antenna itself. Try to keep the antenna away from other metal in the system such as batteries and PCB ground plane. The following types of antenna are recommended.

Blink More LED :D

noreply@blogger.com (ayie) — Mon, 28 Sep 2009 23:48:00 +0000

Congratulation, you have succeded with make a LED blink. Now lets improve your skill by making more LED blink ( 8 LED ). In this lesson, we will make four LED blink change reversed.

Step 1st
Build the circuit as shown in figure 2.1.2. As you seen on figure 2.1.2. P0.0 trough P0.7 is connected to LED's katode each. Remember, that all we want to do with this lesson is make four LED blink change reversed.

Microcontroller Application LED

Figure 2.1.2. Diagram Skematik LED Blink

Step 2nd
In this step, you must tipe the assembly program to make four LED blink, we assume that you have already known the editor, we used MIDE-51 to edit the program.

org 0h
start: mov P0,#11110000b; Turn on LED on P0.0 - P0.3
call delay ; call delay time
mov P0,#00001111b; Turn on LED on P3.4 - P0.7
call delay; call delay time
sjmp start; loooooop forever to start
;=============================================
;subroutine delay created to rise delay time
;=============================================
delay: mov R1,#255
del1: mov R2,#255
del2: djnz R2,del2
djnz R1,del1
ret
end

Step 3rd
Safe your assembly program above, and name it with LED2.asm (for example) Compile the program that you have been save by using MIDE-51, see the software instruction.

Step 4th
Download your hex file ( LED2.hex ) into the microcontroller by using Microcontroller ATMEL ISP software, see the instruction.After download this hex file you'll see the action of the LED ( of course if your cable connection and your program are corrected ).

Atmel : Blink LED Tutorial

noreply@blogger.com (ayie) — Fri, 25 Sep 2009 07:13:00 +0000

Making a LED Blink

The first step is to build a simple circuit. At this point you should be familiar with the parts used. (1 resistors, and 1 LED). This design is intended for use with an Atmel 89s51 but also posible for others family 8051. Most microcontrollers can handle the current required to turn an LED on and off but. In this lesson we're going to make a LED Blink continously.

Step 1st
Build the circuit as shown in figure 2.1.1 As you seen on figure 2.1.1 P0.0 is connected to LED's katode. Remember, that all we want to do with this lesson is make a LED blink.

Figure 2.1.1 Diagram Skematik LED Blink

Step 2nd
In this step, you must tipe the assembly program to make the LED blink, we assume that you have already known the editor, we used MIDE-51 to edit the program. ( Download File : blink_led )

org 0h
start: Clr P0.0 ; send '0' to P0.0
call delay; call delay time
Setb P0.0 ; send '1' to P0.0
call delay; call delay time
sjmp start; loooooop forever to start
;=============================================
;subroutine delay created to rise delay time
;=============================================
delay: mov R1,#255
del1: mov R2,#255
del2: djnz R2,del2
djnz R1,del1
ret
end

Step 3rd
Safe your assembly program above, and name it with LED1.asm (for example) Compile the program that you have been save by using MIDE-51, see the software instruction.

Step 4th
Download your hex file ( LED1.hex ) into the microcontroller by using Microcontroller ATMEL ISP software, see the instruction.After download this hex file you'll see the action of the LED ( of course if your cable connection and your program are corrected ).

Eagle CAD Software

noreply@blogger.com (ayie) — Fri, 25 Sep 2009 06:50:00 +0000

This is the use full software for electronic student. It's help student to save the time when create and design the electronic circuit. For me its very help me on design the circuit.

you can download the software from .

here