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 […]
Category: electronics
Previously I added 555 timer in astable mode to generate pulses for the counter chips. In the next step a second 555 chip is added. This timer runs in bistable mode (see pg. 176 of Make:Electronics). The purpose of this timer is to freeze the counting when the tactile switch is pressed (figure 4-40 of […]
The next step in Experiment 18 of Make:Electronics is the addition of a 555 timer in astable mode to the circuit (pg. 175 of the book). This addition drives the decade counter therefore the tactile switch that was connected to pin 1 of the first decade counter from the previous part of the experiment had […]
Last Friday I’ve built the circuit as displayed in figure 4-37 (pg. 174) of the book Make:Electronics. The circuit consists of (in my case) three Kingbright 7 segmented digits. Each digit was connected to a 4026 decade counter. The decade counters are coupled by connecting the output of pin 5 (carry) to the clock input […]
With the arrival of the Kingbright numeric LED with the correct width (see my earlier post) I was able to continue experiment 18 of the book Make:Electronics (pg. 170). In this experiment the reader will eventually build a reaction timer using the 555 timer chip and 4026 decade counter. The layout of my numeric LED […]
I wanted to continue with experiment 18 of the book Make:Electronics today but discovered that the Kingbright numeral LED’s that I received were the wrong type after all. The width of the component is to small to fit in the breadboard (it is 2/10 inch instead of 3/10 inch). I ordered the 3/10 numeral LED’s […]
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Experiment 18: More components.
A small update. Saturday I received the rest of the components that I need for the Reaction Timer (Experiment 18 of Make:Electronics) and the rest of chapter 4. I couldn’t get all the components on the shopping list (see pg. 147) from my online supplier so I had to choose some alternative components. Notably the […]
I reread the part of Make:Electronics about the inside of the 555 timer in the astable mode (page 162 of the book) hoping that this would give me a clue about what went wrong with the Valentine LED chaser. This gave me the idea that the 1 uF capacitor connected to the pin 6 of […]
Last Friday and Saturday I transferred the components to the perf board. I used regular perf board this time instead of the breadboard type perf board that I used for the alarm circuit. I had to make a sketch of the circuit on the perf board before I started to solder. The sketch was simply […]
It is time to take a temporary departure from Make:Electronics. The question is: has all these theory and experiments from the book enabled me to finish my own project? After working with the 555 timer in astable mode last week I remembered an article about this chip that I read a year ago, the so […]