72 channels Serial (SPI) to parallel driver board has been designed for various applications. This project can be used as multi Solenoid driver, large size 7 segment display driver, bar graph driver, and LED driver. The project works with 5V logic levels. Output load supply 12V-48V DC and each output can drive 500mA load. I […]
72 CHANNELS SERIAL TO PARALLEL DRIVER BOARD USING 74HC595 & ULN2803 Read More »
The revolutionary Intel 8008 microprocessor is 45 years old today (March 13, 2017), so I figured it’s time for a blog post on reverse-engineering its internal circuits. One of the interesting things about old computers is how they implemented things in unexpected ways, and the 8008 is no exception. Compared to modern architectures, one unusual
Analyzing the vintage 8008 processor from die photos Read More »
First steps in circuit design for the budding electrical engineer. San Francisco, CA (October 25, 2018)—A Beginner’s Guide to Circuits ($17.95, 80 pp., October 2018) introduces beginners to the magic of electronics. With easy-to-follow instructions, it’s sure to be the perfect book for young readers who want to understand the everyday electronics around them and gain the
A BEGINNER’S GUIDE TO CIRCUITS Read More »
What’s inside a TTL chip? To find out, I opened up a 74181 ALU chip, took high-resolution die photos, and reverse-engineered the chip.1 Inside I found several types of gates, implemented with interesting circuitry and unusual transistors. The 74181 was a popular chip in the 1970s used to perform calculations in the arithmetic-logic unit (ALU)
Inside the 74181 ALU chip: die photos and reverse engineering Read More »
Researchers at Cambridge University have just achieved a spectacular breakthrough in electronics design. They have developed new ultralow power transistors that could function for months or even years without a battery. These transistors look for energy from the environment around, thus reducing the amount of power used. Dr Sungsik Lee, one of the researchers at
Ultralow Power Transistors Function for Years Without Batteries Read More »
Exactly 30 years ago a great disaster struck the region of Chernobyl: a nuclear accident occurred that released a large quantity of radioactive particles into the atmosphere. And it is only five years ago that, with the Fukushima Daiichi nuclear disaster, a second similar catastrophic event has taken place. These anniversaries did not directly let me build a PIN Photodiode based Geiger Counter,
Building a PIN Diode Geiger Counter Read More »
Most inexpensive pushbutton switches, particularly pc-board-mounting and membrane types, have momentary action. Latching types are often larger and relatively expensive, and they frequently are unavailable in the style you’d like to use. You can thus have a problem if you need a small, inexpensive on/off switch for latching power to a load. The circuit in
Latching power switch uses momentary-action pushbutton Read More »
This project uses an Arduino, a pair of speakers, and a laser pointer to create a laser projector able to trace out designs in a dark room. To power it, I’ve cannibalized a PC ATX power supply capable of delivering plenty of current for the speakers. Most of this project was directly adapted from the
Arduino Laser Show (adapted from NothingLabs’ Instructable) Read More »
One of the directors has asked me to create a special backdrop for our college musical. This particular backdrop has a particular design (see below) that includes LED strip lighting to give the feel of a 1920s casino sign – similar to what is seen today in Las Vegas. I have done up a detailed
Arduino and Transistors Question – RE: School Musical Production Read More »
