I skipped experiment 24 of Make: Electronics. The reason is that I’m not really interested (at least not right now) in completing the Intrusion Alarm. I do appreciate what the author of the book, Charles Platt, is trying to achieve. He gives a couple of good hints for upgrades of the Alarm without presenting the […]
Tag: make:electronics
In this part of experiment 23 of Make: Electronics the binary counter from part 1 is upgraded to a dice simulator (figure 4-109 on page 219). A 74LS27 chip is added. This chip has three NOR gates of which one is used for this experiment. Also an LED display is added. The configuration of this […]
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 […]
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 […]
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 […]
While working on the Atari Punk Console I reread the part of chaining chips in Experiment 17 of Make:Electronics (pg167). I then realized that I didn’t do all the experiments that are described in the book. Since Experiment 17 contains a lot of information and chaining 555 chips is common practice in electronics I decided […]
I (almost) finished the reaction timer today. That means that the delay is build in. This was done by adding yet another 555 timer now in monostable mode. It is triggered with a tactile switch connected to pin 2 of the timer (see pg. 178 of Make:Electronics). During testing of the circuit the LED switched […]