High power ultraviolet LED experiments

From bigclivedotcom. Some experiments to see how a selection of series capacitors affects the power dissipation and output of a 50W near-ultraviolet LED. The small motor-run capacitors look very promising for reducing the heat dissipation and extending the LED lifespan of these LED modules. Be aware that these capacitors do not have discharge resistors and…

2032 lithium cell charger with reverse polarity test

From bigclivedotcom. These USB powered chargers are only suitable for charging the LIR2032 rechargeable versions of the lithium button cells. Do not put a non rechargeable cell into them. Note that the rechargeable cells are not suitable for all devices intended for a CR2032 non-rechargeable cell. Instead of providing a fairly consistent 3V for the…

Inside a Bumble Ball – with schematic

From bigclivedotcom. The circuitry in this toy was more sophisticated than I was expecting. Mainly for safety and electrical interference reasons. These were apparently first marketed as a dog toy, then evolved to become a kids toy too. The construction is mechanically quite complex to allow activation of a free spinning assembly inside the ball.…

How to use the XH-M452 temperature and humidity module

From bigclivedotcom. This very common general purpose module has two sections – temperature and humidity. Each section has its own volt-free relay contact. The heating section can control either heating or cooling (but not both) and the humidity section can control humidifying or dehumidifying. If switching mains power or high loads I recommend using an…