## Aiken code – Excess 3 code

Aiken code – Excess 3 code

Aiken BCD code is similar to the natural BCD code, but with “weights” or “values” distributed differently.

The Excess 3 Code is obtained by adding “3” to each combination of the natural BCD code.

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## Logic probe circuit using CD4001 IC

Logic probe circuit with CD4001 IC

This logic probe circuit is useful for people who needs an instrument to measure the logic levels on digital circuits. This circuit is implemented with CMOS IC technology and is recommended for testing circuits using the same technology

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## The Binary Number System

The binary number system

The binary number system. unlike the Decimal number System, where they are allowed 10 digits (0 to 9), you only need two (2) digits: “0” and “1”.

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## BCD Code: Binary Coded Decimal

BCD Code In order to share information in digital format, it is common to use a binary or hexadecimal representations (BCD Code). There are other methods to represent this information and one of them is the BCD code. By using the BCD coding is easy to see the relationship between a decimal number (base 10) and the corresponding […]

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## Sequential circuit

What is a Sequential circuit? The main difference between a combinational circuit and a sequential circuit is that in the sequential circuit there is a feedback from one or more of the outputs to one or more of the inputs. You can see that the output of the OR gate is feedbacked to the input of the lower AND gate. This means that the […]

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## Digital Logic Levels (hight, low, 0, 1)

Digital Logic Levels (hight, low, 0, 1) In digital circuits is common to say that we have a “high or a “low” logic level at the input or output of a circuit. If we have a “high” level we say it is a “1” and if we have a “low” level we say that it is a “0”. If we were using […]

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## Logic OR gate

Logic OR gate The logic Or gate is one of the simplest digital logic gates. The output of this gate is high, when one or all of its inputs are high. The OR gate is represented by the following Boolean function: X =A+B or X=B+A. (for a 2 input OR gate) Two Input logic OR gate The following picture shows […]

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## What is a Truth Table?

What is a Truth Table?

The Truth Table is used to simplify boolean equations obtained from digital circuits. The truth tables can have many columns, but all tables operate in the same way.

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## What is a Logic Circuit?

What is a logic Circuit?

A Logic circuit uses two logic levels to transfer the information. A hight logic level or “1” and a low logic level or “0”. The Logic circuits are made of digital elements such as the AND gate, the OR gate, the NOT gate and a combinations of them.

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