Old PSTN entry phone - door opening - #5

Arrived the PCBs !!!

I couldn't resist and immediately started to put together the first official prototype and ... did found a problem !!!

Previous articles :

• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-1.html
• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-2.html
• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-3.html
• https://hanixdiy.blogspot.com/2020/06/old-pstn-entry-phone-door-opening-4.html

Old PSTN entry phone - door opening - #4

In this article I'm  describing the final version of hardware and firmware for the door opening.

Previous articles :

• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-1.html
• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-2.html
• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-3.html

Old PSTN entry phone - door opening - #3

In this article I will discuss  about how to design a circuit capable to "read" the rotary dial and relative code.

Old PSTN entry phone - door opening - #2

 In the previous article I discussed about some theory of operations and how to deal with the hardware.
In this article will start to discuss more in details about the hardware we want to design based on a real example.

Old PSTN entry phone - door opening - #1

This can be an interesting project.
The idea is to use an old PSTN phone to control the user end of an entry phone system.

Different functionalities can be developed, this article is concentrated to the door opening one.

The idea is to interface the rotary dial of an old PSTN phone with a small MCU capable to decode a number composed with the rotary dial and activate a relay if a specific number is selected.

A family size UV sterilizer - intro

In this time of COVID is necessary to sterilize often things, like masks and objects.

To do so I decided to build an UV-C Box Sterilizer.
UV lights are used to sterilize object since ... forever :). On the market exists UV sterilizer for phones and small objects but this is the point, is not easy to fit in it many objects.

Thus the idea to build a bigger box capable to easily sterilize everyday objects, including facial masks and small PPE.
I will update this article every time I will add more information/details about the construction/test.

3D Printing - repairing a Jlab headphone

For many years I did buy a headphone from a company called Jlab.
They are cheap (< 30$) and very good sound quality and comfort.

I think I did buy so far 4 or 5 headsets and the reason is because after a while they broke down.

Finally I was able to repair one !

3D Printing - knob replacement

I was asked if it was possible to print a replacement knob for a diagnostic machine.
This article describes what I did and the results.

The knob is for a laboratory machine, a thermal cycler S1000, from Bio-rad.
The knob is in plastic and is quite big.

3D Printing - Protective visor

Another thing that seems missing for many doctors is a protective visor.

I did fin a nice project and did try, not bad.

3D Printing - Covid mask #2

Crazy time !  Another 3D print of a mask that claim to protect from the virus.

I am kind of skeptical about the feasibility and functionality of such solution, then I did find some people pointing out to a project.




At this time I'm NOT endorsing in any way to use this mask as real solution since too many questions are unanswered !