tools, materials & knowledge for model makers
When I run engines on compressed air I often wonder about the efficiency. A large electric motor driving a piston compressor that is in turn supplying a small engine that is sometimes barely able to overcome friction, sometimes quite powerful. So what is the end to end efficiency? So, I googled “Compressed Air System Efficiency” … Read more
A battery pack design could be for a single or group of cells arranged in series and parallel, depending on application this may include: thermal control, electrical switching and management system. In it’s simplest for a phone battery pack design is a single cell that has temperature and voltage monitoring. The battery pack design for … Read more
The Lead Acid Battery is a battery with electrodes of lead oxide and metallic lead that are separated by an electrolyte of sulphuric acid. The overall reaction is: PbO2 + Pb + 2H2SO4 <=> 2PbSO4 + 2H2O Some batteries manufactured for use in very hot or very cold climates may have stronger or weaker acid. … Read more
The Nickel Metal Hydride battery has a nickel-hydroxide cathode, a metal hydride (a variety of metal alloys are used) anode, and aqueous potassium hydroxide electrolyte. This is a rechargeable battery chemistry that has been superseded by lithium ion, but has seen a lot of use in Toyota hybrids. The overall reaction is: 2NiOOH + MH … Read more
In a rechargeable lithium ion battery lithium ions move from the negative electrode to the positive electrode during discharge, and back when charging. The cathode is a lithium transition metal oxide, eg manganese or cobalt or a combination of transitional metals. The anode is a graphite-based material, which can intercalate or release lithium. When charging … Read more
Flywheel design principles, primarily the wheel on the end of the crankshaft that gives the crankshaft momentum to carry the pistons through the compression stroke. Normally constructed from a heavy steel or iron disc. A flywheel has two main functions: Moderating speed fluctuations in an engine through its inertia. Any sudden increase due to fuelling … Read more
I was reading an article about using a fuel cell energy storage system for a drone and how it was a high energy density option. This made me wonder how a fuel cell works and what options there are around for the model maker. What is a fuel cell? A device that converts the chemical … Read more