Letter from Chris of PyroElectro.com in 2013
Here’s a project I know your readers will love! It’s an all-digital-hardware LED Christmas tree we’re calling the Christmas Tree O’Digital Logic.
The tree itself is composed of 64 LEDs built into a spiral sitting on a piece of protoboard. Underneath, the controller uses shift registers and a 555 timer to create two modes of display: a predictable pattern and a random pattern. This should light up any desk or shelf and bring merriment to your readers!
We’re also running a Kickstarter campaign to fund our second free online electronics course, “An Introduction To Digital Electronics.” We have just 4 days left to raise $2,124. If you would be so kind as to spread the word about our efforts, we’d be extremely grateful!
To build the tree, we’ll use 63 green LEDs and 1 red LED. Lots of wire will be needed to make the spiral + cone shape of LEDs from top to bottom. To build a random pulse generator, we’ll use some digital logic trickery with a 7404 hex inverter. A 555 timer will be used to drive 8 shift registers, which will control all 64 of the LEDs. Finally, a 4 bit timer should be thrown into the circuit in case we want to slow things down with a divider.
Many projects and schematics related to Audio, Guitar, Amplifiers, synthesizers and Music Circuits. There are even Valve Amp and Computer related ideas.
Steve Conner of Scopeboy – Tesla to Inverters
“I’ve been building Tesla coils for about 4 years. I was inspired to start when I saw some pictures of Tesla coils making sparks on the internet, and wanted to experience one for myself. After my first attempt, I decided to join the online community of coil builders and try some of the new state-of-the-art ideas that were kicking around.”
Amazing Tesla Coils of Steve Conner
- An 0-30V, 500mA bench power supply
- How to make gyrators
- Boosting a tube amp with a transistor one
- Grid-tied inverter – 1/2 KW
An android virtual instrument – OsciPrime is an Open Source Android high speed data acquisition hardware platform and Android oscilloscope application.
Open Source Android Oscilloscope
Using USB, the hardware plugs into Android devices that support USB Host. Together with the OsciPrime Android oscilloscope application it turns a tablet or mobile phone into a high speed data acquisition system.
OsciPrime Oscilloscope Android App
- 2x Analogue Input @ 8bit/6Msps
- 5 analogue gain levels
- 3.3 MHz – 8.0 MHz Bandwidth (gain dependant)
- 16 V Max Input Voltage
- 880 mW Power Consumption
- Designed for 10x Probes
The Android App Instrument Performance and Controls Include
Controls -V-Offset, Time-Offset, Calibration; Trigger Controls Falling/Rising and Edge, You can Measure Voltage, Freq and Period.
- Range +/- 1.5 V up to +/- 16 V
- 5 us/Div max – 1 ms/Div min
- Processing 400’000 samples per second
History and accomplishments of the General Radio Company, one of America’s first equipment manufacturers for the radio and electronics industry.
General Radio Historical Society
Founded in Cambridge, Massachusetts in 1915, GR provided the tools and instruments that allowed the electronics industry to burgeon into today’s giant that fills our lives with radio, TV, computers, cell phones, DVDs and all the other electronic products in our homes, businesses and automobiles.
General Radio Experimenter
This pioneer publication first appeared in June 1926 and became the model for many others to follow (most notably the HP Journal). It began with engineers talking to radio amateur customers and gradually changed to engineers talking to other engineers, who might also be customers.
GenRad 1863 Megohmmeter
The GenRad 1863 Megohmmeter is the choice for production and inspection tests on devices with resistances up to 20 Tohms.
Read more at my EEMetric Genrad Wiki Stub