A small update on the filtering experiment 29 of Make: Electronics that I wrote about earlier this week. To improve audibility especially of the lower frequencies I had to built an enclosure. The book proposes a plastic box but I had a shoebox made out of cardboard lying around. I cut a circular hole in […]
Tag: electronics
Finally, after earlier setback, I’ve got the amplifier and 4-inch speaker working properly. I tried multiple setups today and managed to get rid of the distortion. The book dictates 9V, 33K resistance on audio input. This results in my case in a temperature of 90 degrees (194 fahrenheit). Which is uncomfortably high. I therefore decreased […]
This experiment of Make: Electronics demonstrates the use of self-inductance and capacitance in audio filtering. The low and high frequencies of the audio signal can be separated and send to different speakers (woofer and tweeter). The audio chip used for this experiment is the TEA2025B, a somewhat older chip that was used in portable radio […]
After making an improvised coil (experiment 25) and cutting a coil out of a speaker (experiment 27) in this experiment the self-inductance of a coil is demonstrated. As a coil in this experiment I used 44 meters of coated copper wire on a spool. In parallel with the coil two low current LED’s are connected. […]
I couldn’t get the cylindrical neodymium magnet of the required size so I skipped experiment 26. Next experiment 27: Loudspeaker Destruction of Make: Electronics is a very simple and very short experiment but worthwhile nevertheless. It demonstrates how a loudspeaker works by literally cut it to pieces. Luckily I had an old 2 inch speaker […]
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 […]
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 […]