Happy 40th Anniversary to the First Computer Mouse!

A mouse (Not the pesky rodent!) is a pointing device, where it functions by detecting two-dimensional motion relative to its supporting surface. To be more precise, a mouse consists of an object that holds under one of the user’s hands, with one or more buttons. As you can see, the contemporary computer mouse has a wheel that allows the user to perform various system-dependent operations. Do you know that inventor Douglas Engelbart was creating the first computer mouse on Dec 9, 1968? After a glorious 40th anniversary years, Douglas said, “Although there’s been an explosion of technology in the past 4 decades, it hasn’t reached the level of potential he envisioned in the early 1960s yet!”

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The Great PLL Induction Heater Driver

Have you ever played with a manually tuned induction heater before? If you did, then you must know that how dull it could be… Oh, for those that didn’t know what the induction heater is, that is a key piece of equipment used in all forms of induction heating. An induction heater will technically operate at either medium frequency (MF) or radiofrequency (RF) ranges. Three main components form the basis of a modern induction heater, such as the power unit (power inverter), the word head (transformer), and the coil (inductor). This project is slightly different from the regular induction heater driver, as it will include the Phase Lock Loop (PLL) into it. A phase lock loop is a control system that can generate a signal, and it has a fixed relation to the phase of a “reference” signal itself. Since the phase lock loop circuit responds to both the frequency and the input signals phase, it raises or lowers the frequency of a controlled oscillator automatically until it’s matched to the reference in both frequency and phase. Overall, this PLL induction heater driver will be one of the magnificent projects that you’ve ever built!

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Great method of PCB reverse engineering by using a Photoshop

Rriccibitti has sent us his latest work on reverse engineering of simple keypad circuit. The solution seems to be very simple but effective. He used a digital camera to take a picture of the printed circuit board and a photo editing software to track PCB traces with different colors. OK, for this one, he used Photoshop to have lots of valuable tools that make this work much more manageable. To be more specific, let us see what he’s done:

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Circuit Diagram

A circuit diagram is also known as an electrical diagram, wiring diagram, elementary diagram, or electronic schematic. It is a simplified conventional symbolic representation of an electrical circuit. It shows the circuit components using easily understood symbols and the power and signal connections between the devices. The components’ arrangement and their interconnections on the diagram do not correspond to their physical locations in the finished device. Unlike a block diagram or layout diagram, a circuit diagram shows the actual wire connections being used. The chart does not in any way represent the physical arrangement of components. Circuit diagrams are used for the design, construction, and maintenance of electrical and electronic equipment.

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Analog Circuit Design

constant_current_LED_driver_circuit

Today’s modern circuit design is a bit of a conglomerate thanks to the availability of sophisticated process technologies that have made bipolar and CMOS (Complementary Metal Oxide Semiconductor), power and signal, passive and active components available, all on the same die. From this point on, it is up to the circuit designer’s ingenuity to assemble these components into the analog and/or logic building blocks that are deemed necessary to develop the intended system on a chip.

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Free pascal compiler for 8051 microcontrollers

If you like to work with 8051 microcontrollers and like Pascal programming language, here is Turbo51 – a free Pascal compiler for the 8051 families of microcontrollers. In the 1980s, Intel introduced the 8051 as the first member of the MCS-51 family of microcontrollers. Today hundreds of cheap 8051 derivatives are available from tens of manufacturers. This makes the MCS-51 architecture so interesting for professionals and hobbyists. It is a somewhat surprising fact that this 8-bit architecture is still in use today. In other words, it is still trendy. Several C compilers are available for the 8051. However, there are only a few Pascal compilers for the 8051 families available. There are many debates on which programming language is better. Turbo51 is for those who prefer Pascal. Turbo51 features a fast single pass optimizing compiler, Borland Turbo Pascal 7 syntax, full floating point support, mixed Pascal and assembler programming, full use of register banks, advanced multi-pass optimizer, smart linker, generates compact high-quality code, output formats include binary, Intel HEX and assembler source.

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DS1803 Digital Potentiometer – The Great Variable Resistor

You’re still frustrated with your old-fashioned and limited functions potentiometer? Instead of being annoyed by it, why don’t you spend several hours making a DS1803 digital potentiometer? With this DS1803 digital potentiometer, you can easily control the resistance over its range in the programmable action and then send it commands over a 2-Wire (12C/TWI) serial interface in a second! This means you can hook it up to another microcontroller, such as the most popular Arduino, and then adjust the program’s resistance. It would be best if you chose DS1803 because it is compatible with the program, it can be operated in either 3V or 5V, and you can choose from a few different models with various resistance ranges. For the project, you can create a tiny PCB, were consists of two DS1803s. You will get four potentiometers on this board since each of the DS1803 has two potentiometers!

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DIY an USB Audio DAC and Leave More Green Cow in Your Wallet!

Have immensely interest in the audio DAC design, and would like to DIY a low cost but powerful audio DAC? Ok, now you have the chance, as you’ll learn to create your very own audio DAC today. You will use the circuit PCM2902 for this project, where you will need to design the DAC from USB with this circuit on a one-sided PCB! Since the circuit board is a well designed wrong board, everything besides the crystal and USB connector will be placed from the bottom. Below here is the schematic diagram from datasheet of PCM2902.

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DIY Class A MOSFET Headphone Amplifier Can’t Even Be Easy Than Before!

You’re not satisfied with your desktop headphone amplifier? Then, just stop the complaint and DIY Class A MOSFET headphone amplifier! First, you will need to use a regulated power supply, which can be purchased from Radio Shack (10-20VDC and 750mA should be OK). The regulated power supply is responsible for regulating the power supply will ripple the rejection and eliminate any noise in the power supply. An IRF610 MOSFET and an LM317 regulator will be used in the Class A Mosfet headphone amplifier. Here is the step-by-step guide for the project; let’s get started… Firstly, you have to prepare an external CD-ROM (It would be better to have a power switch, power adapter receptacle, RCA inputs on the back, and headphone jack on the front). The amplifier is constructed on 2″ square protoboards from Radio Shack. You will need to assemble these components onto the board:

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