Jonathan entered a Flickering Jack-o’-lantern for the Open 7400 Logic Competition. He recorded a video of his project, which is available below. I used a 74HC14 to create four different square waves of different non-harmonic frequencies that were mixed together to flicker a red and blue LED. Via the contact form.
Embeddederic entered a 7400 series logic PLL-based switch-mode power supply into the Open 7400 Logic Competition. Via the forum.
Jason added another entry to the Open 7400 Logic Competition: 80M direct conversion receiver I had fun using the 74HCU04 to make a little TRF AM radio, but my original goal was to build a direct conversion receiver. I didn’t think I would have time before the deadline, but I managed to squeeze it in with […]
Andrey entered a Game of Life build from CMOS logic into the Open 7400 Logic Competition: This was supposed to be my entry for Open 7400 logic competition. It’s Conway Game of Life on 8×8 LED dot matrix, made with almost only 74HC and 4000/4500 series of CMOS logic chips. Via the contact form.
Arup entered his Homemade 7400 into the Open 7400 Logic Competition. A video of it proving his concept is available below. At an earlier post I’ve said that I didn’t have 7400ICs in my drawer. Surprisingly, the local store was saying 74HC00 out of stock. Hence I decided to make my own 7400 IC. 7400 […]
Shaos entered a (balanced) ternary electronic device based on the 74HC4052 into the Open 7400 Logic Competition. Ternary Balanced ternary is a base-3 number system, instead of bits (0, 1, 10, 11, etc), this counts in trits (-1, 0, 1): The “Test bed” consists of 20 sockets for testing “our standard ternary components“. For ternary […]
Kevin entered a Detailed consumer IR capture with 74HCxx series chips for the Open 7400 Logic Competition: This is a CIR (Consumer IR / Remote Control) capture device built with 74HCxx series logic chips. It allows a computer to do a detailed capture with carrier frequency, on/off durations, and on duration pulse counts. Via the […]
Matt built a fully featured Drum machine for the Open 7400 Logic Competition. Check out the video of its operation and his sound generating skills below. This is a four-channel, sixteen-step percussion synthesizer/sequencer created entirely from discrete logic chips (mostly 74HC-series parts). That’s right, no microcontroller or software of any sort. It was created for […]
Joe entered his Horologium Romanum into the Open 7400 Logic Competition. It is a clock that displays it’s time in Roman numerals built from logic ICs. There is a video of it below. Despite the Roman Empire’s sanitation, medicine, education, wine, public order, irrigation, roads, fresh-water system, and public health: they never had a decent […]
Luc entered his Wheely bin night reminder into the Open 7400 Logic Competition: Because the competition was so open ended in its brief, I placed two constraints on myself: First, I had to make do with the logic chips (and other components) I had on hand. No going to Jaycar or placing an order through […]
After being discouraged by a failed order for their initial entry, Ben and his girlfriend decided to enter a somewhat different design into the Open 7400 Logic Competition. It consists of taking their anger out on 7400 chip. By pumping 1 Amp of current at 12V into the IC, they turned it into a heater, […]
Daniel entered an Electronic realization of Etch-A-Sketch toy into the Open 7400 Logic Competition: This project is an electronic realization of the famous Ohio Arts “Etch-A-Sketch” toy, with a twist. Like the original, two rotary knobs are used to move a cursor horizontally and vertically, respectively, but unlike the original, a third knob selects one […]
Christopher created a Drum Machine for the Open 7400 Logic Competition. He also documented it in a video below. The idea for building a drum machine came from a discussion I had with my roommates in which we were talking about the popularity of drum machines as simple web applications. I decided to try to […]
Juan entered an Accelerometer controlled racing game into the Open 7400 Logic Competition. Check out the video of the gameplay below. My project is a simple video game in which you control a car and have to move it sideways in order to avoid obstacles. Via the contact form.
Reymond entered a CD4007-Based Voice Changer into the Open 7400 Logic Competition: The project uses 2 – CD4007 configured as a Gilbert Cell Double Balanced Modulator and an additional 2 – CD4007 for use as a difference amplifier. This kind of effect is known as a Ring Modulator in the audio community… Via the contact […]
Alvaro built a Capacitance meter out of logic chips for the Open 7400 Logic Competition. His project measures capacitance of a capacitor and displays it on a 7-segment display. It works by using the said capacitor in a RC oscillator, which changes its output frequency proportionally to the capacitance in it’s RC circuit. The frequency […]
Michael entered a TEC temperature controller into the Open 7400 Logic Competition. Logic chips control the temperature of a thermoelectric Peltier element (TEC) heating/cooling plate. Current temperature is measured via a sensor placed directly on the Peltier. The target temperature is set by an 8bit dip-switch. The circuit will cool or heat the Peltier until […]
Michael built an LED clock for the Open 7400 Logic Competition. He added 60 LEDs to an analog clock which are controlled by discrete logic chips. This project uses a standard analog quartz clock and adds 60 LEDs clockwise around it to display the seconds. There are 2 selectable modes via 2 jumpers: Mode 1: […]
Andrew entered an AM radio transmitter into the Open 7400 Logic Competition: My 7400 contest entry is an AM Radio Transmitter, which nicely complements another entry. The TX frequency is digitally tunable from 520kHz – 1.6MHz, although this part of the circuit is open loop, so tuning to a specific frequency may require a slight […]
Chris decided to enter another project into the Open 7400 Logic Competition. The beeping down counter, as it’s name suggests, is a pre-settable timer which beeps and uses a display to show the seconds left on the timer. The goal of this project is to duplicate the down counting circuit used by the character Ivan […]