Here’s an inexpensive electronic circuit that you can build to put in your Jack-o’lantern. It provides power to drive a few LEDs at night, and automatically turns them off during the daytime. It’s a simple and automatic dark-detecting circuit that you can use to for your very own photosensitive pumpkin.
Dark detecting circuit - [Link]
It’s half a century since the first integrated circuit was demonstrated by Jack Kilby at Texas Instruments Jack Kilby’s first integrated circuit
If it wasn’t for the invention of the integrated circuit, then computers today would probably be housed in huge mahogany cabinets with a baffling array of polished, brass valves, or at least be stuffed into huge boxes containing hand-soldered transistors. We owe a lot of thanks to the integrated circuit, or microchip, which is today celebrating its 50th birthday.
The first microchip (pictured) was first demonstrated by Jack Kilby from Texas Instruments on 12 September 1958. It might not be much to look at, but then Texas Instruments admits that Kilby often remarked that if he’d known he’d be showing the first working integrated circuit for the next 40-plus years, he would’ve ‘prettied it up a little.’ The chip worked, though, producing a sine wave on an oscilloscope screen at the demo.
The integrated circuit itself is the germanium strip that you can see in the middle of the glass slide, and it measured 7/16in by 1/16in. With protruding wires, and just containing a single transistor, some resistors and a capacitor, it’s a primitive chip by today’s standards. However, it opened the gate for mass production of larger-scale chips that could contain more and more transistors without the need for complicated hand-soldering jobs.
Integrated circuit is 50 years old today – [Link]
This java applet is an electronic circuit simulator. When the applet starts up you will see a simple LRC circuit. The green color indicates positive voltage. The gray color indicates ground. A red color indicates negative voltage. The moving yellow dots indicate current.
To turn a switch on or off, just click on it. If you move the mouse over any component of the circuit, you will see a short description of that component and its current state in the lower right corner of the window. To modify a component, move the mouse over it, click the right mouse button (or control-click if you have a Mac) and select “Edit”.
Java electronic circuit simulator – [Link]
Aki writes:The electric circuit board for controlling stepper motors came out after figuring out all the specifications of the components. Some sketches were necessary to done. Then Auto-Cad was a great tool for drawing the wires and locate the components. Mainly my circuit is similar than shown in Mel’s page. I didn’t use opto-isolators and couldn’t find TIP120 from a local electric dealer, so I used TIP122 transistors. I also placed the small hand-pad diodes on the board instead of installing them inside of the hand-pad. After soldering work and changing the InverterOutPut (!) to 1 the board started to work. [via]
Stepper Motor Circuit Boards - [Link]
This is a simple description (some kind of engineering reversing ) of cheap KeyChain Lasers that are sold for 5 bucks or so.The laser diode head has three pins labeled: LDC (Laser Diode Cathode), PDA (Photo Diode Anode) and COM+ (common Positive Terminal).Inside the laser diode head we find the laser diode itself and a photodiode, used to regulate the laser diode current with an external feedback loop. [via]
Keychain LASER driver circuit - [Link]
Electronic Printed Circuit Board Layout Software that is a cost effective, easy to use electronic printed circuit board PCB layout application. Features: Export Gerber RS274X and Excellon NC drill. Import ASCII netlist. Up to 16 layer boards supported. Rulers, Guidelines and Dimensioning lines. Five libraries – new components and libraries can be added. Automated ground planes, isolated copper removal. Tracks snap to pads for easy routing. Multiple Undo / Redo. [via]
Rimu PCB - [Link]
Although i linked to some DIY tutorials on printed circuit board making in the past, i decided to write my own tutorial to cover all the bits and pieces so that any beginner with no knowledge can obtain a PCB using the photo etching method. Lets start with the tools and materials i used:
DIY Printed Circuit Board Using Photo Etching Method - [Link]
What is Chaos theory? Chaos theory is the theory that describes systems that appear disordered, but also this theory is about finding underlying order in apparently random data. According to Wikipedia:
Chaos theory describes the behavior of certain nonlinear dynamical systems that may exhibit dynamics that are highly sensitive to initial conditions (popularly referred to as the butterfly effect). As a result of this sensitivity, the behavior of chaotic systems appears to be random.
Surpisingly, chaotic effects appear on systems that are deterministic, that means it appears on systems without random elements involved. According to another definition:
A chaotic system is one where the system’s variable quantities satisfy deterministic mathematical equations (i. e., present values may be calculated from past ones), while at the same time being highly irregular, but still contained within a finite region (the “strange attractor”).
Did you know that chaos can be represented using simple electronic circuits and appear on your oscilloscope’ s screen? A circuit that can differentiate a voltage is able to represent the differential equations describing a chaotic system thus appear “attractors” on your oscilloscope. On the site bellow you will find some simple chaos-generating electronic circuits that will “blow your scope”!!
Schematics representing Chaos theory - [Link]