After-market safety treatment of low cost products

There was a time when it was not possible to obtain a proper pure sine wave inverter (12 V DC -> 220 VAC 50 Hz) without shelling out hundreds of Euros or USD.

Today, with the massification of supply and demand, and with the sheer scale of the chinese industry producing these types of devices for consumer and industrial applications, prices necessarily went down.

Until recently I had a modified sine wave inverter, which given its limited compatibility with different types of loads, I have discarded (resold) and went looking for a cheap pure sine wave (which intuitively I expected to be much cheaper in current days).

Through Aliexpress, I found a 500 Watt/1000 Watt peak for 38 Euros (roughly the price I paid for the modified sine wave model years ago - and it was only rated to 250 Watts):

There is nothing like an Enterprise grade solution for a Consumer grade problem

In current times, there is an ever increasing separation between the consumer and physical storage media as a product: with the generalized increase of Internet availability and bandwidth along with massification of server side infrastructures to support storage and other services (e.g. from providers such as Dropbox, Google, Amazon, Microsoft), the user tends to replace the physical storage by the convenience of a cloud storage solution.

"Wheel-bearing" Rotifer

Peltier-based dehumidifier

This simple apparatus is a particularly interesting way of demonstrating the principle behind the common household dehumidifier:

The big difference however, lies in the way the low temperature (required for the condensation of the water vapour) is achieved.

Reconditioning a 50+ year old microscope - part 3 - LED conversion

The microscope came with what I believe it must have been the original illumination system:

• a 30 Watt / 110 Volts tungsten bulb (in this case a GE branded one):

Reconditioning a 50+ year old microscope - part 2 - XY specimen stage mechanism lubrication

Like pretty much every moving part in this microscope, the XY specimen stage mechanism also suffered from dried/sticky grease, preventing the X axis from moving at all. As such like in the previous case, the only solution was to tear it down, clean it and apply new grease and oil.

The separation of the mechanism from the stage is simple: in the bottom of the geared side (where the knobs are) this forelock is moved as shown in the picture, and by moving the Y axis to the end of its travel range, the mechanism is removed:

Reconditioning a 50+ year old microscope - part 1 - Fine Focus recovery

I thought of giving my daughter a toy microscope, to let her know of some of the things that exist but go beyond what the eyes can see. But from searching in toy stores, I could not find any product that seemed to inspire proper optical quality. Some products seemed both expensive and very basic at the same time. Some products averaged 50 Euros retail, VAT included.

So I tried to take a look at what eBay had to offer. I quickly turned my attention to real lab grade microscopes. Some were obviously very expensive, but a very wide range of offer in price/age/condition could be found. After some extensive browsing, I managed to calibrate my price expectations and define a budget. My reasoning was that given I had a initial intention of buying a 50 Euro toy microscope, now that I was looking at real lab grade microscopes, I should at least relax my budget to be double that value. I even considered going beyond that, if I found an item that I could see, decide and obtain locally (decreased risk).