[Marc] has an old Voigtländer Vito CLR film camera. The camera originally came with an analog light meter built-in. The meter consisted of a type of solar panel hooked up to a coil and a needle. As more light reached the solar panel, the coil became energized more and more, which moved the needle farther and farther. It was a simple way of doing things, but it has a down side. The photo panels stop working over time. That’s why [Marc] decided to build a custom light meter using newer technology.
[Marc] had to work within the confines of the tiny space inside of the camera. He chose to use a LM3914 bar display driver IC as the primary component. This chip can sense an input voltage against a reference voltage and then display the result by illuminating a single LED from a row of ten LEDs.
[Marc] used a photo cell from an old calculator to detect the ambient light. This acts as a current source, but he needed a voltage source. He designed a transimpedence amplifier into his circuit to convert the current into a voltage. The circuit is powered with two 3V coil cell batteries, regulated to 5V. The 5V acts as his reference voltage for the display driver. With that in mind, [Marc] had to amplify this signal further.
It didn’t end there, though. [Marc] discovered that when sampling natural light, the system worked as intended. When he sampled light from incandescent light bulbs, he did not get the expected output. This turned out to be caused by the fact that incandescent lights flicker at a rate of 50/60 Hz. His sensor was picking this up and the sinusoidal output was causing problems in his circuit. He remedied this by adding two filtering capacitors.
The whole circuit fits on a tiny PCB that slides right into position where the original light meter used to be. It’s impressive how perfectly it fits considering everything that is happening in this circuit.
When a project starts off by heating acid to its boiling point we say no thanks. But then again we’re more for the projects that use ones and zeros or a hot soldering iron. If you’re comfortable with the chemistry like [Michail] this might be right up your alley. He used boiling acid to expose and photograph the die from several integrated circuits.
The title of our feature is a play on words. In this case, die refers to the silicone on which the IC has been etched. To protect it the hardware manufacturer first attaches the metal pins to the die, then encapsulates it in plastic. [Michail] removes that plastic case by heating sulfuric acid to about 300 degrees Celsius (that’s 572 Fahrenheit) then submerges the chips in the acid inside of a sealed container for about forty minutes. Some of the larger packages require multiple trips through the acid bath. After this he takes detailed pictures of the die and uses post processing to color enhance them.
This isn’t the only way to get to the guts of a chip. We’ve seen nitric acid and even tree sap (in the form of bow rosin) do the trick.
Although technology is constantly racing to faster / smaller / more, so many of the fundamentals of how it is made remains similar, if not the same. This interesting 30 minute video clip [thanks to The Computer History Museum] was made in 1967 by Fairchild Semiconductor as a briefing on integrated circuits, and shows the different steps to produce ICs including:
Design, making the photo masks, manufacturing the silicon ingots, preparing the wafers, building of the circuit and its components (like transistors, resistors, and capacitors), testing, and final packaging. Add in some other cool items of interest such as a 1960’s pick n place machine, wave soldering, an automatic wirewrap machine, and toss in some retro computer action and it’s surely a video worth watching, with something for everyone.
So join us after the break, kick back and enjoy the show!
Continue reading “A Briefing on Integrated Circuits”
Lazarus-64, breadboard game system; certainly sounds like something from the 1980s. We were surprised to find out not only the name, but also all the ICs used are only those available from the retro age of 30 years back (Save for the AVR controlling everything, of course). Even more amazing is how it has 256 flicker free color support, while not using NTSC chips. Which Goes to show that even if there are common solutions out there for cheap, building or compiling your own is not necessarily a bad thing or a waste of time.
There is a whole lot more to Lazarus, including double buffering and VMS, but sadly it appears progress has stopped on the Lazarus-64 breadboard game system, with the last update being last year. But we can still bask in the amazing glow that currently is.
[Jeri Ellsworth] made this silicon inverter at home, by hand. It took her two years to get the process figured out and achieve something we didn’t think was possible. The complexity of manufacture, and the wide range of tools and materials needed seem insurmountable but she did it anyway. Her home chip fab Flickr set is well commented and details her work area and part of the processing. If you’re hurting for more check out her 40 minute Metalab talk which we’ve embedded after the break.
If her name sounds familiar but you just can’t place it you may know her from The Fatman and Circuit Girl. We’ve also featured some of her hacks, such as her Pinball challenge against [Ben Heckendorn], and her giant Etch-a-Sketch.
Continue reading “Jeri makes integrated circuits”
Who doesn’t need to take pictures of the microscopic bits inside of an integrated circuit? [Mojobojo] made an end-run around the expensive equipment by building a microscopic lens from an old camcorder. He’s using a regular digital camera with the lens set to its largest zoom level. The camera is pointed into the salvaged camcorder lens where the fine tuning is done. His first iteration was just taped to the desk with a small hand flashlight illuminating the subject. He upgraded that setup by building a LEGO enclosure and changing to a much brighter light source. The images he’s getting are quite surprising and this will be very useful during those extreme hacks when you need to tap into an IC’s internal data rails.
[Aggaz] added 16 potentiometers to his Arduinome.The Arduinome is a monome clone based around the Arduino as a microprocessor. We seen some Arduinome builds in the past but [Aggaz’s] work augments the physical interface.
Potentiometers used in circuit bending allow for manipulation of the sounds coming out of the circuits. In this case the pots are connected to the microcontroller instead of the sound generation circuitry which means you can do whatever you want with them depending on how creative you are with the code. So far he’s just starting to get the new set of interfaces to play nicely over the serial connection. This could end up being quite popular as it only requires the addition of a multiplexer IC, the potentiometers, and the knobs.