How to design solar reflectors for solar cookers
Using multiple reflector angles. Solar box oven cookers cannot always be tilted to face the sun if the sun is low in the sky. Doing so may cause the cooking pot to tip over, or if the pot is on a swivel base, it may already be at it''s maximum swivel angle.
BB-8''s dimensions
Toggle navigation rimstar . BB-8''s dimensions. BB-8 Main: BB-8 (v1) Main: BB-8 (v2) Main: At this time the only dimension we''re reasonably sure of is that the diameter of BB-8''s ball in the movie is 506mm, which is 19.92" (inches). If you''re dealing in inches then 20" will look fine. I''ve explained below how I got all the measurements so
Gravity light (v2)
The lights were three of the LEDs (shown below) which I bought on ebay here.Each LED is actually made of multiple tiny LEDs. If you watch the Gravity light - Making video below carefully at 2:44 you''ll see that only some of those tiny LEDs actually light up, though as the power is increased they light up very brightly. But the price was low enough for experimenting like this.
DIY laser communicator
Toggle navigation rimstar . DIY laser communicator. This is a relatively easy to make laser communicator which allows you to talk over a distance using a laser on one end and a solar cell on the other end, along with a few extra parts. The
Hero''s steam engine
Toggle navigation rimstar . Hero''s steam engine. Here''s a very easy to make steam engine, Hero''s steam engine. It''s named after Hero of Alexandria who described it in a document in the 1st century AD. It consists of an unopened soda can with two tiny holes in either side and a little water inside. Heating the can heats some of the water to
20kV DC power supply (homemade/DIY) using flyback with built
This is different than my 30kV high voltage power supply that used a flyback transformer without built in diodes and a Cockcroft-Walton voltage multiplier or tripler that contained the diodes (see photos below.) However, the multiplier does allow that one to get to 30kV. On the other hand, this commercially made multipler is hard to find, as it the flyback without built in diodes.
Communicating via laser to photoresistor
I''d previously made a laser communicator for transmitting to a solar cell but I''d been asked to also try transmitting to a photoresistor (also known as a photocell or LDR - Light-Depentent Resistor.) I came up with a circuit design that worked, and the resulting sound was much better than with the solar cell. A video of it in action is given below.
How to find true south for aligning solar collectors
Method 2: Using a shadow at solar noon. Perhaps the simplest way to find true south is to wait until noon and then look at your shadows. The edges of the shadows of things that are perpendicular to the earth/standing straight up line up with true south/north.
30kV DC Power Supply (homemade/DIY) using flyback and
IMPORTANT: It''s recommended that if you might have high power sparks then you should put around 250 kilohms of resistance with at least a 2 watt rating at the output to protect the power supply from the high current of the spark. A high power spark usually comes from a wide spark gap. I damaged transistor Q1 this way by forgetting to put this resistance.
rimstar
rimstar - Solar/wind, composting, non-conventional energy/propulsion. rimstar An addiction to science, renewable energy, building stuff, understanding how things work, and passing it all on to you. What''s New February 25, 2023 Added a downloadable files for making zoetrope animations and
Heat transfer/loss formula and how to calculate it
where: heat_transferred is the amount of heat transferred, either lost or gained, through the material separating both sides (BTU / hour) ; surface_area is the surface area of the material separating the two areas that are at different temperatures, it''s the material that the heat is being transferred through (Examples: wall, window) (ft 2),
Donate/support RimstarOrg
Toggle navigation rimstar . Donate/support RimstarOrg. Thanks for visiting my website, and watching my videos! And thank you for wishing to donate but as my website and videos are currently not very active, I''m not looking for donations at this time. Your continued enjoyment and use of this content is thanks enough.
Crystal earphone/earpiece
Toggle navigation rimstar . Crystal earphone/earpiece. Crystal earpieces, or earphones, consist of a piezoelectric crystal attached to a diaphragm (see diagram below.) The fluctuating voltage from the crystal radio''s output is
Wimshurst machine with 2 sectors as LC circuit
This is a replication of something done by one of the members of the testatika Yahoogroup modifies two sectors of a Wimshurst machine to act as the capacitor(s) of an LC resonant circuit with a coil wrapped around the pulley shaft.
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What''s New February 25, 2023 Added a downloadable files for making zoetrope animations and a downloadable template for making a pinhole camera from poster board. February 21, 2023 Added a downloadable template for making the corona motor v2. November 24, 2022 Added details about Izzy, an artificial intelligence robot I''m working on and my changes to the darknet neural
rimstar
rimstar sharing information that keeps the lights on. What''s New Archive: August 23, 2009: DIY installation of commercial solar pool heating system in Seattle. August 20, 2009: Modifying commercial Wimshurst machine - added replacement screw information. August 16, 2009:
DIY multi-range gauss/millitesla meter
At a nominal Zero Gauss field strength, meter +ve input at the C3/R5 junction is ≈ 2.5V. VR1 sets the probe range Calibration Check Voltage at 4.5V (Equivalent to ≈ full scale) VR2 sets the Green/Red (N/S ) switching threshold for the LEDs.
Short Stories
Gunther answered "It was common in ancient Egypt, both in their artwork and as actual objects. There is some speculation that it was imported from Syria but that''s only one of the theories. It''s basically a pedestal made of alternating narrow and wide
Solar cooking
The Copenhagen solar cooker is a clever design that has the cooking pot sit flat while the reflectors are adjusted around it. Since the reflectors are flexible, you can get a fairly good amount of sunlight reflected to the pot whether the sun is low or high in the sky.
Electronic Symbols
Toggle navigation rimstar . Electronic Symbols. Video - How to Read a Schematic. The following is an introductory level video for how to read a schematic. A list of symbols is given below. Electronic symbols. The following are electronic symbols used in schematics. Categories of the electronic symbols below; Power and ground: Switches:
rimstar
What''s New February 25, 2023 Added a downloadable files for making zoetrope animations and a downloadable template for making a pinhole camera from poster board. February 21, 2023 Added a downloadable template for making the corona motor v2. November 24, 2022 Added details about Izzy, an artificial intelligence robot I''m working on and my
Sizing the solar array for you off-grid solar power system
Toggle navigation rimstar . Sizing the solar array for you off-grid solar power system. Step 1. Work out your power needs: Step 2. Sizing battery bank: Step 3. Sizing solar array: Step 4. Wire sizing: NOTE: Clicking on any link in the body portion of this page will take you to a new window or tab so that you don''t lose any information.
Hero''s steam engine
Toggle navigation rimstar . Hero''s steam engine. Here''s a very easy to make steam engine, Hero''s steam engine. It''s named after Hero of Alexandria who described it in a document in the 1st century AD. It consists of an unopened
Reconstruction and vital repairs underway in Syria, as ''security
1 天前· The UN aid coordination office, OCHA, reports that the rehabilitation of key facilities has begun in the northwest of Syria – the first area to fall to opposition fighters on the road to
Wimshurst machine
The Wimshurst machine is an electrostatic machine that normally has a crank that you turn by hand, resulting in the creation of sparks. Below is shown a commercially made Wimshurst machine bought on ebay .I''ve taken this Wimhurst machine apart so you can see it.