Experiment 23 of Make: Electronics uses 74LSxx chips (TTL chips) instead of the 74HCxx (CMOS) that has been used in previous experiments. In the first part of this experiment a simple binary counter in made (figure 4-102). I ordered some low current LED’s especially for this experiment to be able to see the output of […]
Author: Eric Buijs
I’m an #privacy, #opensource, #opendata and #openstandards advocate. I’m holding a grudge against Big Tech, big IP holders and authoritharian governments. Furthermore I’m a #3Ddesigner, #3Dprinter, #webdesigner and overall #DIY guy.
Begin this week I created a simple Audio Amplifier with the LM386 (see previous entry). I noted that there was some noise coming from the speakers. I already had a 100uF capacitor on the breadboard to smoothen the power fluctuations. I searched the internet for solutions to further reduce the noise. I found three possible […]
While waiting for some components for Experiment 23 of Make: Electronics I decided to create a simple Audio Amplifier. I had a LM386 chip lying around which is more than adequate for this purpose. My first goal was to create an amplifier circuit with it on the breadboard and do some experimenting with it. Maybe […]
Experiment 22 of the book Make: Electronics is a simple experiment to demonstrate use the 74HC02 logic chip as a flip-flop. The 74HC02 is a logic chip with four NOR gates. The schematic of this experiment can be found in figure 4-98 on page 21 of the book. A SPDT switch is used to flip the circuit […]
Experiment 21: Race to Place from Make: Electronics describes a circuit useful for a quiz show like Jeopardy. Pushing a button lights an LED and locks the button of the other player(s). The two player schematic is depicted in figure 4-95 on page 208 of the book and is built around the 74HC32 logic chip […]
A friend of mine brought in his PC that had, according to him, some issues. I’m not an IT security expert but I’m the guy that family and friends turn to if they have problems with their computer. These problems can vary from malware, adware, slow computer and so on. I decided to boot the […]
After having done most of the circuitry of Experiment 20 yesterday today I connected the relay and all loose wires from the keypad to the circuit. I had to read the description of some of the experiments with relays earlier in the book Make: Electronics (e.g. experiment 7) again to be able to wire the relay […]
Experiment 20 of Make:Electronics describes a hardware device that protects a computer (or any other electrical device) from being used unless a specific numeric code is entered on a keypad. The experiment is built around two 7400 logic chips (74HC08 and 74HC04). These chips process the input from the keyboard and trigger a 555 chip […]
With experiment 19 of Make:Electronics I’m entering the world of pure digital electronics. This experiment explains the basics of the 7400 family chips. It is also a prelude to experiment 20. First an LM7805 voltage regulator is used to to provide precisely 5 volts DC. Then a simple circuit is built around the 74HC00 chip […]
I finally finished the Atari Punk Console (APC) that I blogged about previously. This time I worked on the external connections and the enclosure. First I took a cheap grey project box and drilled holes for the two potentiometers, speaker and LED into the lid. I also drilled a hole for the perf board and […]