Light Flasher

This is a very basic circuit for flashing one or more LEDS and also to alternately flash one or more LEDs.
It uses a 555 timer setup as an astable multivibrator with a variable frequency.
With the preset at its max. the flashing rate of the LED is about 1/2 a second. It can be increased by increasing the value of the capacitor from 10uF to a higher value. For example if it is increased to 22uF the flashing rate becomes 1 second.

There is also provision to convert it into an alternating flasher. You just have to connect a LED and a 330ohm as shown in Fig.2 to the points X and Y of Fig.1. Then both the LEDs flash alternately.

Atmel AT89Sxxxx Series Min-Sys

INTRODUCTION

Now this is another kind of design but use a minimum system types using Atmel MCS51 S-series with ISP programming. So with this kind of board, the chip do not need to remove just programmed on board. Programed using ISP programming could be done directly through LPT parallel port. There are many programming software could be found on the internet. Some that I could find and much realiable eq.: AEC-ISP programmer, this kind is DOS version. Could be download at : AEC-Electronics. Also ISP programmer made by Asim Khan, could be download at : Asim Khan's ISP software, this kind is a windows version. Besides that there is software from Adam Dybkowsky which run both version of programmers. It could be found at : Adam's Home Page ISP PROG ATMEL89Sxx. Every programmers used its own ISP cable.

On Tauhid

Allah--ta`ala--has said: "I have not created jinn and
mankind except to serve Me . . . And to every people We sent a
prophet to convey to them that they ought to serve Allah and
avoid at-taghot. . . . Your Lord has decreed that you shall
serve none but Him, and show kindness to your parents . . .
Serve Allah and do not associate aught with Him . . . Come, let
me tell you what your Lord has forbidden you; namely, that you
do not associate aught with Him." (Qor'an 51:56, 16:36, 17:23,
4:36, 6:151-153)

Basic SR flipflops

Circuit Description

This circuit demonstrates the basic SR (for set-reset) flipflops built from NAND and NOR gates. The typical structure of both circuits are the feedback lines that connect the output of one gate back to the input of the other gate.

The behavior of both circuits is very similar; the most important feature is that the circuits are able to store information. Please play with the circuits and compare the simulation with the function (or state) tables on the right of the schematics.

In all normal states, the output of the two gates are inverse to each other, which means that a flipflop circuit can generate both the Q output value and the inverted NQ output value at no extra cost. Naturally, the so called forbidden states don't damage the circuit, but they should be avoided because in those states the outputs of the two gates are not complementary to each other.