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Monday, October 24, 2016

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.

Saturday, September 10, 2016

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:

Saturday, August 27, 2016

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).

Saturday, March 26, 2016

Repurposing an old Android Phone

I had an old Samsung Galaxy Y (GT-S5360) which the previous user didn't particularly enjoy for its performance and replaced with a fancier, newer model. With no obvious use to give to the device, I decided to repurpose it for building some kind of a remote monitoring/observation station, and try to find out how it stands out against the harsh outside environment.

While not attempting to simply put the device outside, directly exposed to the sun, rain and extremes of temperature, I made several customizations to better prepare the smartphone turned into a monitoring station.

The first thing I wanted was to have it entirely self-sustainable. As such I bought a 10 watt photovoltaic panel to harvest the energy required by the device: