This short uses a CD4026, a 7 segment display, 9V battery, some resistors, an IR LED and a CdS photocell or phototransistor. Break the IR beam and the display advances to the next digit. https://www.facebook.com/reel/525596709839365?mibextid=9drbnH
Archive for the ‘Optoelectronics’ Category:
2024-05-13 Autonomous Solar Tracking System
For each direction of travel, it consists of two solar cells connected in parallel opposing to a motor that’s geared down to turn the tracking so both solar cells are in the shade. https://www.facebook.com/reel/7341922389263306?mibextid=9drbnH&s=yWDuG2&fs=e
2023-07-09 Groundbreaking Research Transmits Energy From Space To Earth
This is definitely groundbreaking. But I don’t understand why they’re doing it this way. I think the array that’s in space should be as simple as possible – an array made up of thin sheets of metallized mylar that reflect the sunlight to the photovoltaic array on Earth. In their system and mine, there has
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2020-06-11 Optocouplers Don’t Always Protect
From FB comment Monty Ross It’s true that optocouplers are used for isolation. But I have seen whole sections of PC boards with a hole burned where the optocouplers used to be. It is incredible how much damage the power lines do to the PC boards due to high voltage spikes in the power. Transformers
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2017-07-13 Don’t Use Your Original Remote Control
From FB reply My remotes seem to go bad all the time. Batteries low or dead, battery juice leaking on the circuit board, broken wires from falling off the table, getting sticky or worn, etc. I try to minimize the wear and tear on the original remote. I never use the original remote, I use a cheap
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2016-02-23 Joule Thief With Daylight Shutoff
I designed my Blue Blinky with a daylight shutoff, using a LED as the light sensor and an additional transistor to amplify the minuscule current that the LED puts out. This worked just great because there is the point across the timing capacitor where the current is very low, and it takes very little current
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2015-05-03 Light Emitting Paper
Quantsuff emailed us a link about a new material summarized at Newscientist.com. I have a few thoughts that I’d like to add. The stuff should be great for illumination. But I have doubts about its use for display purposes. Displays have millions of very small pixels. If one or a few get contaminated with dust
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2014-03-19 7 Year Long Running Joule Thief
A few months ago I came across a 7 Year Joule Thief video from Xee2vids on YouTube (link below). It’s a conventional Joule Thief except that the resistor has been increased to 2 megohms, and a 100 pF capacitor has been added from the resistor to ground. He calculates that the LED should run for
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2013-11-20 LEDs Power TE Flasher, Not JT Flasher
My recent two blogs on powering a flasher with four red LEDs used a flasher made by modifying a Joule Thief. It works fine, but it requires a toroid core and wire; the flasher I blogged earlier does not require any inductor. It is a switched capacitor or charge pump,. and it works okay with
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