Outrageous, creepy, and utterly awesome!
Waaaaay back when I was in elementary school I made a tree decorated with several cranes made of 25mm (1") colored foil squares, and it received an award in our school's art competition. The cranes took some time to get right, but they looked like jewelry. I tried to make some of these a couple of years ago, but my much larger fingers got in the way! Kudos to you!
Two devices that are rated for 4.5A *may* require up to 9A, but this would happen only if both devices are pulling their maximum rated current at the same time. Whether this happens at all really depends on the devices themselves.
Christine,Thanks for the reply; I understand your design choices. As for the MAX6921 chip putting out higher voltages, that's not a problem for LEDs as long as the current setting resistor for the chip is set properly. If you decide to try this chip in the future, I can help you determine the right resistance value.
WiFi 7 Segment LED Clock
I really like this project a lot! The woodworking is very nice, and you clearly did a fair amount of planning. I love the use of a tablet to set/read the date and time and access other functions!I have a few questions about the project:1) Have you double-checked the Fritzing schematic? You show the power indicator LED and its series current dropping resistor in *series* with the 12V supply's positive connection in the switched wire. This means all of the current for running the clock flows through the LED, and depending on the different clock functions the current may exceed the LED's rated current. Typically LEDs for power indication are connected in parallel to the switched input power wires. This way it's much easier to select a proper resistor value (the Fritzing schematic shows 33 ...
I really like this project a lot! The woodworking is very nice, and you clearly did a fair amount of planning. I love the use of a tablet to set/read the date and time and access other functions!I have a few questions about the project:1) Have you double-checked the Fritzing schematic? You show the power indicator LED and its series current dropping resistor in *series* with the 12V supply's positive connection in the switched wire. This means all of the current for running the clock flows through the LED, and depending on the different clock functions the current may exceed the LED's rated current. Typically LEDs for power indication are connected in parallel to the switched input power wires. This way it's much easier to select a proper resistor value (the Fritzing schematic shows 33 ohms, but the parts list shows a 330 ohm resistor).2) Is the board really a WeMOS R1 D2, or is it a WeMOS D1 R2? 3) Does the 5V from the DC-DC converter go to the 5V on the WeMOS board? You show it going to Vin on the Uno, but for driving Unos directly from a 5V supply it's best to connect the supply to the Uno's 5V pin.4) Are you really using the HDSP-C2G1 LED display as shown in the 609986,pdf? This display doesn't seem to be available in blue, and each segment would require more than 5V to light up.
Without a resistor to limit current, these may not last very long. Red LEDs have lower forward voltage ratings (usually around 2V, so the current through them can be much higher than their maximum rated current. Luckily the batteries *usually* contain enough internal resistance to keep from destroying the LED, but the high current means lower battery life.
The LEDs might light up, but not as brightly as they would with battery voltage that matches the LED's specified forward voltage.
The smaller batteries contain less energy, so they won't last as long. However they might be a better option for red LEDs whose lower forward voltage can result in destructive current from larger cells. Smaller cells have higher internal resistance, and this serve to reduce the current to less-destructive levels.
Nice circuit - very well thought out and presented just as nicely. Kudos!
Heat also helps deplete mast cells of histamine, so much so that long, hot showers can be very effective in relieving the itch of sunburned skin for several hours.
No, I don't know of any in the same package shape/size that are pre-wired. Cool project nonetheless!
Very nice! I'd recommend using a LiPo battery that already has wires or soldering tabs attached, as this reduces the likelihood of damaging the battery by overheating. And zinc fluxes are highly corrosive, so they should be washed off after using; I personally recommend not using them for electronics in general. Finally, you might want to define POI for people who do not understand what it means.
Nice job, Matt. I may just have to make this to increase my tiny workshop's capabilities!
Nice hack, and certainly suitable for an electronics enthusiast. I've done this basic hack several times in the past 45 years, and it is a simple way to make a personal guitar (or utility) amp while recycling an old radio. To minimize hiss it's a good idea to twist tightly the wires from the audio jack.
This is really cool! Does it really use 128 glue sticks or 64? It looks like 64 (8 x 8 matrix), but the material list calls for 128.
Nice, simple amp that people can experiment with. Output power will depend on several factors, but mostly on how efficiently the heat sink dissipates the power in the MOSFET.
This would be a very cool project for collaboration between math, science, and workshop (and electronics or other STEM classes - if present) in a high-school or college setting. Everybody would stand to learn something from the others.
Indeed! Wood is great for laser marking, but it takes some experimenting to get the speed and power just right. Low-detail images often look best with a slightly de-focused beam, but high-detail images usually require sharp focus. I prefer hardwoods for laser engraving; the contrast is stunning!
Woods can be tricky to engrave with a laser, but some tweaking of power and speed (dwell time per dot and off-time between dots) can produce exceptional results. This image was produced (on a laser engraver I designed, built, and programmed myself) on 4”x4”x1/4” maple block.
Sure, but that’s not the point. Lots of people will learn about eddy currents and the relationship between electricity and magnetism. It would have been nice if the author had explained how eddy currents give rise (pun intended) to heating, but this is still a very nice instructable that was highly instructive!
It is a good idea to incorporate a sensor, and I think a temperature sensor just below the cooking surface (perhaps embedded in the Lexan) would also be useful.
Coding can be a hurdle for lots of hobbyists, especially when it comes to the use of libraries (most of which IMHO are poorly documented). My usual recommendation when starting to learn how to code is to start small and take baby steps.
These are definitely common mistakes, and your suggestions are excellent. I’d like to add that the process is frequently iterative; just because a schematic is available online doesn’t mean that the circuit is robust. Luckily there are fairly knowledgeable people in most of the major forums, and these folks can be very helpful if/when a circuit doesn’t work as expected.
Sewing Tools and Supplies
Overall I like the project, but I have to advise against soldering directly to the batteries or tabs. Lithium batteries store a LOT of energy, and when they fail they are capable of reaching very high temperatures. Some of these batteries can easily be damaged by soldering heat. If somebody is interested in doing this project, I recommend that they buy the 18650 batteries with tabs and use appropriate connectors.
This IS a touch switch, even if you have to touch more than one wire at a time; it’s just that the capacitive touch switches that are more common nowadays give the impression to lots of people that a single electrode is the only “proper” configuration for a touch switch.What’s interesting to note is that the ability of the MOSFET to stay in either the ON or OFF state is due to the presence of gate capacitance coupled with a VERY high leakage resistance through the gate oxide layer.
Awesome project and a great write-up. It shows how much work often is necessary to end up with a quality result! The neatness of the finished assembly hides all the intricate work - kudos for accomplishing this AND sharing your trials and tribulations along the way!
Getting Started with Electronics
Nice project! You might want to edit the materials list to correct the plywood specifications for both panels/sheets: they are currently spec'd out as 1 x 8 feet, but should be 4 x 8.
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