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Practical Electronics Learning with DIY. Practical Experiments forge the book, college or web learning into a Skill.

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Thursday, August 13, 2020

Beetle Robot guided by Light

First have a look at this How to Build a Robot a BeetleBot. This sparked the long lost memory of a book i read around 35 years back. My age was in single digits. This was when i had neither an idea of electronics or could afford any parts.

I had built many physics projects like weighing scale, gramophone, telegraph system, crystal radio. I will try to explain these later. Calling bells, gears and magnets from the flea markets my source of electricity & magnetism.

Beetle Robot guided by Light

I read a hobby book from UK for children. It was a Beetle Car Bot, with four wheels and 4 light sensors. It could be LDR or photo-transistors, i do not remember. The light sensors were at the four corners of the car. The maneuvering was by variation in the speed of each wheel. It was based on germanium transistors mostly.

Four large lamps like 40W, had to be mounted on the ceiling, at the four corners of the room. By turning on and off these lights, this bot could go anywhere in the room. The whole book with pictures was dedicated to one bot and how-to build one.

Now that we have PIC and AVR; we can use Dimmable LED Lightning arrays to guide the bot. The challenge is in the mechanics of the bot, we have to forget that we have wireless for some time. Try this out.

Friday, August 07, 2020

GainClone Chipamp Audio Amplifier

Gainclone or chipamp is a type of audio amplifier made by do-it-yourselfers, or individuals interested in DIY audio. It is a design based on high-power integrated circuits, particularly the National Semiconductor Overture series.

GainClone Chipamp Audio Amplifier

The Gainclone is probably the most commonly built and well-known amplifier project amongst hobbyists. It is simple to build and involves only a few readily accessible, inexpensive parts. As an amplifier it is highly regarded by many in the DIY community.

GainClone Chipamp Audio Amplifier

GainClone Amplifier Rod Elliott (ESP)

"The amp is based on the Project 19 PCB, so uses a pair of LM3876 (or LM3886) power opamps, run from a ±35V supply. ...........The power supply is conventional in almost all respects. I used a 160VA transformer, a 400V 35A bridge rectifier, and a total of 20,000uF per supply rail - 4 x 10,000uF caps in all."

Recording Technology History

1877 - Edison made the first recording of a human voice ("Mary had a little lamb") on the first tinfoil cylinder phonograph Dec. 6 (the word "Halloo" may have been recorded in July on an early paper model derived from his 1876 telegraph repeater) and filed for an American patent

Dec. 24. John Kruesi built this first practical machine Dec. 1-6 from a sketch given to him by Edison that was made Nov. 29 (not on "Aug. 12" that Edison mistakenly wrote on another sketch in 1917).

Recording Technology History - https://www.aes.org/aeshc/

Edison Phonograph

When Kruesi heard Edison's first words Dec. 6, he exclaimed "Gott in Himmel!" (but these words for "God in Heaven" were not recorded and thus have been forgotten). Others before Edison had tried to record sound, but Edison and his tinfoil phonograph were the first to succeed.

History of sound recording

The phonograph expanded on the principles of the phonautograph. Perfected by Thomas Edison in 1878, the phonograph was a device with a cylinder covered with an impressionable material such as tin foil, lead, or wax on which a stylus etched grooves.