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Wednesday, April 17, 2019

Once again bumping into questionable product safety standards



About 6 months ago, I replaced the manual plastic pump I used to have for dispensing water from 5+ litre jugs, with what would in principle be a more sophisticated and convenient approach: looked for an electric water dispenser, and without much searching, found several options. Most, if not all were unfortunately designed to fit into the 19 litre office water bottles. Without any alternative, ordered one of these, considering that I would have to come up with some custom adaptation if I wanted to use it with the 5 litre bottles. Ended up ordering the one below, for its minimally elegant design and compact dimensions:


Wednesday, January 30, 2019

Car DVR replacement and related shenanigans - part 2

Moving along with more details, like I mentioned in the previous post, the rear camera was reused from the previous installation. This CCD based camera happens to be superior to the basic CMOS camera bundled with the kit. Both in terms of the quality of the sensor itself and its low light sensitivity, but also regarding the lens, featuring a wider viewing angle (important given its role as a backup camera).

The only change however was a substantial improvement in the mounting design, by having added an U-shaped plate in the rear of the camera, with a 4-screw mount instead of the original 2 screws attached to the sides of the camera. This provides a more solid attachment to the L-shaped aluminium parts that in turn stick to the door through an adhesive:


Sunday, January 27, 2019

Car DVR replacement and related shenanigans

Introduction

With the vulgarisation of miniature cameras and computing devices of all sorts, technologies that fundamentally serve the mobile industry become cheap enough and available to the point of being useful for other purposes. That is the case of DVR devices for automotive use.

Saturday, January 5, 2019

Adding metalurgical capability to a biological microscope - part 2

Like I had previously explained, I was able to obtain from eBay (for a minimally decent cost), just the bare vertical illuminator, which didn't include any accessories. The light house was not an exception. The vertical illuminator consists the main body:



and the light house, which in the original device would be based on a halogen bulb of at least 15-20 Watts:


Sunday, December 9, 2018

Adding metalurgical capability to a biological microscope - part 1

Biological microscopes among a few other things, are characterized by the fact that rely on transmitted light rather than reflected light, to produce an image of the specimen.This is adequate for most biological needs because the specimen can either be made thin enough for light to go through, or the medium and/or the specimen itself is relatively transparent to light.

However there are other applications in microscopy where it cannot be assumed that the specimen is transparent or able to be ground to a thickness small enough for light to traverse it. Some materials are opaque even at thicknesses of few microns.

The only solution in these cases is to rely on reflected light. For this to be possible, a different illumination system is required on a microscope. This type of illumination is commonly designated of epi-illumination (as opposed to trans-illumination used for biological observations). This is where a device known as vertical illuminator comes into play (picture obtained from a Olympus BHM manual):


Sunday, September 2, 2018

4-wheel adventures ranging from customer relationship to automotive hacking

1. Context

Since more than a decade ago, automotive technology have captured my interest to some extent. Not so much in the mechanical domain, for which the industry have in most part been over the years conservative and slow in pushing inovation, but mostly in respect to the digital framework that integrates the vehicles. This overlay of digital technology plays a fundamental role in modern cars, ranging from safety, fuel economy, controlling the production cost (by reducing the number of individual parts), emissions control, comfort and entertainment.

Sunday, July 15, 2018

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):