Monday, August 18, 2014

Binary and Hex Numbers

Computers understand numbers and logic, as most are digital computers. The Binary Hexadecimal System is the way the numbers or logical commands are instructed to the computer. All input devices or sensors must finally talk this language to the CPU, and all outputs and actuators must be able to understand this numbers to do their job.

Binary and Hex Numbers

A bimetallic thermostat is like a simple mechanical computer. Where the bimetal response is the sensor input, the contacts are the output to actuator and the bimetal thermal behavior is of the nature of intelligence. Similarly we have opamps which can be real-time complex analog computers. And the Living Being are like biologicals robot which have all the things - a control systems, computers, sensors and actuators, even probably a wireless network. :-)

Binary Numbers
  • Bit is 0 or 1 ... one digit ... 0 could be 0 volts and 1 five volts.
  • Nibble is four bits, 4 digits, like 0010 , in hex a nibble is 0 to F.
  • Byte is eight bits, 8 digits, like 1100 0010 , in hex 00 to FF.
  • BCD binary coded decimal is binary code for numbers 0 to 9.
  • Learn more by reading asciicat here. Download and use.
Computer Science and of computer programming, while emphasizing the development and analysis of common data structures and algorithms.

CS152, Fundamentals of Computer Science II, and Programming Languages.

A Tutorial on Binary Numbers

Samuel A. Rebelsky
  • Basic Concepts Behind the Binary System
  • Binary Addition
  • Binary Multiplication
  • Binary Division
  • Conversion from Decimal to Binary
  • Negation in the Binary System
A Tutorial on Binary Numbers

Sunday, August 17, 2014

Resistor Color Code

The Resistors Value has to be Deciphered by understanding the well kept Secret Color Code that is known only to Makers, Ham Radio, and Engineers.

The Resistor have colored painted bands, makes electronic populated PCBs look attractive, but that was not the real purpose. It was an early innovation in what is called now Ergonomics of the Workplace. In other words it makes you spot values easily and also their magnitude.

If you find a black resistor on the PCB with no color stripes, it means it has burnt up and would have values less than 10K. You have to research the design to arrive at the value of that blown device.

1st band - 1st digit - Yellow = 4

2nd band - 2nd digit - Violet = 7

3rd band - Red = 2 -- number of zeros that follow -- means 4700 ohms -- 4.7 kilo ohms or 4k7

Resistor Color Code

For 4 banded ones, MFR 1% first 3 bands represent first three digits, and fourth band stands for the number of zeros that follow. 4.7k will be Yw Vt Bk Bn.

Right End Band is for tolerance

Brown Band 1% -- MFR Metal Film Resistor is used in Instrumentation Electronics.

Gold Band 5% -- CFR Carbon Film Resistor is common for Consumer Electronics.

Silver Stripe is 10%

Read more at my Basic Electrical Circuits

Thursday, August 14, 2014

Exponents - Giga Tera Pico Nano

In the Metric System you will encounter prefixes for numbers. In electronics, right from resistors to hard disks these units are used. So you have to have in your memory, at least the ones below, so that you place the correct value of cap or inductor in your circuit.

See SI Units or Metric Units to read more about these. R, C and L values are given these prefixes.

We have resistors like 10 Tera Ohms of Glass Surface Resistance to 1 Micro Ohms of a Small Copper Wire Resistance.

1 Pico Farad of Capacitance of two Large PCB Tracks in a Multi Layer PCB to 10 Milli Farad of a Huge Electrolytic Power Supply Filter.

Then Lastly 10 Nano Henrys Inductance of the Twisted Connector Cables in a Computer and 1 Henry of a Powerful Choke that can kickback 10 Kilo Volts when a 10 Amps current thru it is broken.

Exponents
Tera 1000,000,000,000 1.e+12
Giga 1000,000,000 1.e+9
Mega 1000,000 1.e+6
Kilo 1000 1.e+3
units 1 1.e+0
milli 1 / 1000 1.e-3
micro 1 / 1000,000 1.e-6
nano 1 / 1000,000,000 1.e-9
pico 1 / 1000,000,000,000 1.e-12

Electronic Tables and Charts

Electronics is Fun, is it Not.

 Just Google 0.1% or 1000/1e6 or 1000/1000000 ....answer in the calculator that pops up is same. Read "Parts Per Million - PPM" as used in Resistors. 1000 ppm is 0.1%.

Most MFR Resistors have a Temperature Coefficient of 100 ppm/°C.  Read more at ­ Resistance - Ask The Applications Engineer. 100ppm is like 0.01%.

0.01% is close to the resolution of a 4-1/2 Digit Voltmeter. 100.00 is the reading you will see for 100 Volts. Imagine the front end attenuator in that voltmeter is Standard MFR and a "Hot" Voltage Regulator is leaning on it, (you wanted to make your pcb compact)  The last digit will be Spinning like a Ferris Wheel. Are we understanding Instrumentation!

Read - Accuracy, precision & resolution

Parts Per Million - PPM

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