Reusing power sources to power devices of different voltages: voltage converters

42V DC Power 19V 2A regulated DC to charge a laptop that spends 3A

In this post we will see how to feed these appliances we have at home, whose power supplies had stopped working and left, forgotten, in a drawer.

For example, that portable power supply can have a second life and continue feeding any device that requires a power exceeding the capacity (watts) of the transformer. While we maintain the amps equal or exceeding the needings by the apparatus we want to power, we just have to make sure that the voltage output is the same or little less of your device needs.

If for example we need an  e-bike charger, or need a charger of a given voltage, we can adapt economically the output voltage: This is where the boosters and converters come into play modifying voltage DC to DC.

Improving the Ebike with Arduino to monitorize battery and other info 1/2

It is the second time it happens; I pick up the bike, and after the trip to work, the ebike left me without power in the middle of a slope... with the hassle of having to carry their 30 kgs. on a slopes over 14% (and the damage it does to the battery the depth discharge, fortunately are pretty well LiFePo that support this). 

I have no charging indicator (the handle that provided me is to 48V) to calculate if you have enough power for 4 km I have to do, and also the LiFePo4 have a very small voltage variation between 20% and 80% of capacity (between 3,15V and 3,35V), which is easily neglected. And make it load every day is not practical or the best for the battery (ideally recharge when you reach the 20% to maximize battery life). And the battery charge indicators seem to me too "greedy" energy. So...

A solution for every need ...

01/09/17: In the end I finished using a Nano and MPU-6050 accelerometer for burglar alarm functions and voltage indicator, in the 2/2 post from january 2017 you can see the details.

Types of Batterie Management Systems (BMS); building new batteries for our equipment

Complementing the already abundant information on this blog about batteries, recycling and repair, and BMS, I will analyze the types of BMS and qualities that we can find among Chinese BMS. The main reason for the short life of batteries any type is often their poor maintenance ; either because they remain flat or that are downloaded more than convenient (both lead as Li-ion do not tolerate discharges well below a certain level). To protect the batteries (particularly lithium dangerous if overloaded or short -circuited), the " battery Management Systems " or BMS come into play to good use and long battery life.

How to Choose the BMS we need

Solar thermal collector configuration supporting gas/oil boiler

Antonio from Orense had a solar panel with a deposit of 150 lts connected to the same circuit ACS but separately, so that when it was sunny had to walk opening and closing keys to harness this energy and save fuel in the oil boiler.

With solar thermal energy (pre - heat the water with a solar collector) all are advantages. This renewable energy system is today the fastest amortized, usually in two years the installation is amortized, and lasts up to 30 years , with minimal maintenance. It's easy money, and who have not it installed, properly sized, they are throwing money to the trash, literally.

After analyzing your installation of ACS (ignoring the heating pipes), I advised him to use solar thermal as we do; supporting boiler  (gas in our case).

The method is simple; it provides warm water tank directly to the boiler, so that it only has to provide sufficient energy to bring it to the temperature (usually 60 °), and so you forget.

DIY: Avoid overheating problems on your PS3 with a chip and sensor for 5 bucks

With a small chip Digispark ATtiny85 will see how to regulate the fan of the PS3 (or any PWM-controlled fan) depending on temperature, avoiding wear and tear prematurely. 

Engineers PS3 gave priority to the silence of the PS3 , since it is intended to be a center of games and multimedia, so the processors can reach damaging temperatures for the welds thereof, and within a few years ends up breaking down by poor contact welding (reparable only with reflow or reballing).

The PS3 has a pulse PWM controlled fan, Atmel ATtiny85 and can be easily programmed with the Arduino IDE.

There are examples on Youtube and internet people that has regulated the fan fixedlyto go ever faster (with a resistance in the gray wire connected to the 12V, regulating 1V approx., Or with a potentiometer to do it manually) but is not the best solution because it does not consider the processor temperature (which can vary greatly depending on ambient temperature), and although it works, having to cover all cases, there isusually noisier.  and with this solution we have the advantage that if we hear the very loud fan, you will surely have a problem of lack of ventilation dust or other problem.

materials

Centralized control Solar-Biomass mixed system with Arduino and TFT Shield

In this post I will share with you the improvements I've made to our biomass/Solar mixed system , which is basically to change the obsolete control system for thermostats with a centralized system based on Arduino fully customizable, flexible and expandable; we will see the assembly, components and source code.

Applied materials:

   1 - Arduino MEGA 2560 (specifically I used a Funduino clone ), because the TFT shield does not leave me enough inputs / outputs Free UNO R3.

   2 - Touch Screen TFT 2.4 "  McuFriend , which will give us great freedom when it comes to display information on screen libraries that have worked best for me. Are the BUHOSOFT ; here you can download the version I used.

   3 - relays to activate solenoid valves, with a fed to 5V that can handle 230V and 10A worth us to spare.Not to stress regulator Arduino board, the food independently with other L7805 regulator (handles between 7-30V and 1.5A max). Being so low consumption, nor need a heatsink:

   - A speaker-buzzer for alarm warning in case of problems, which operates between 7 and 12V 100dB, enough.

   - A relay SSR DC-DC to activate the buzzer ; only consumes between 3 and 25mA so we can turn directly to the Arduino pin. I used one of solid state more than anything because I had left the other, butsince it is an element that is to be activated soon, you better go to a mechanical more economical and compact:

Save energy with a timed plug: Do it yourself with Arduino

I used this to build a wireless plug socket countdown

I had a Wireless programmable plug Contros of Broadlink with the wifi card damaged:

and I realized that I could come in handy a plug to be activated for a certain time simply by pressing the button, with increments of the same time with each pulse (similar to working electronic microwave, that with each press of the button quick heated adds 30 seconds to the time). A picture is worth a thousand words (explained in spanish, sorry):

Modifying an insertable wood stove to add double combustion and fans

In this post, which had long been "waiting" for various reasons (my apologies to Alberto, intone the mea-culpa), an animated friend of sustainability we discuss how modified 2014 a stove without too much effort to optimize its performance , having fun how nice in the process.

Alberto tells us who dared to take pictures of it and write it done because it came in handy examples and information I put in this blog.

Adding steel tubes for double combustion and fans increase the combustion efficiency to deliver oxygen where it is needed, and also preheated, and fans are needed to optimize the extraction of heat to the room and extend the life of the stove by reducing the temperature of the structure , which otherwise would be very stressed by extreme temperature changes to increase performance. These modifications are safe (with the only danger plaster smoke, controllable and which will be discussed in detail). 

So, without further ado, let him be himself who tell us (apologies for the quality of the photos):

Presentation and project

The first is to introduce Alberto and I am not a professional in this sector, but I like the tools and I dare all.

I needed an insertable for the house in Ávila, at 1360m above the sea, as the chimmenie fire never could heat the cold granite house. And of course I wanted to double and double combustion chamber. 

I do not remember very well the extent of the gap in his fireplace; would be about 530mm, about, quite recently, I found an insertable fire made ​​of that size. The sides of the fireplace are also granite but the problem is securing a roof beam in the middle of the house and did not make me any grace the walls shake too.

So I Have This Test was willing to custom. I was asking for tempered glass in the door to start ... phew... 'find materials that work !!.

By chance I found a home at a low price approaching the measures, and for 250 euros I found very interesting in Leroy Merlin especially since half the work had already been done.

Repairing a Chinese Li-ion battery charger 42V "Rait" brand

The circuit: in one UF1004 dissipating diode and a MOSFET 600V N  MDP11N60 (left)

A collegue had broken his battery charger, he told me that he had left running, hitting an explosion when going to charge his battery 20Ah scooter for the last time .

Normally when a small explosion sounds, it is that any electronic component has gone to hell, so I checked the components and at first sight there was nothing broken, not even the MOSFET had been damaged.

It is  quite simple transformer of 180 / 240VAC to 42 Vdc with 5A load capacity (although the actual output voltage 40,7V are even better for the longevity of the battery), of unknown Chinese brand that came with the battery of 20Ah Chinese acquired.

In reviewing the tracks below, we see what happened: the track that connects with the departure had not stood the peak intensity of the moment to connect to charge the battery (capacitors can deliver a significant current at the time of connection); It is that by design has 3 tracks (possibly to put resistors as a fuse in the Tinned areas) but only one was connected.

Replacing the battery ARRAY Ni-MH battery with a Li-Ion one

In this post we will see another example of updating a NI-MH battery for Li-ion another , much more durable and with no memory effect, in addition to saving bucks in the long run on batteries. These modified batteries are two years running without any problem, and that they were batteries in its final cycle of use, recycled.

Disk arrays on servers usually have an acceleration unit with memory and a battery to prevent data loss in the event that there is a black-out.

Since the Ni-MH array accelerator many HP servers work with 3.6V (three 1.2V rechargeable batteries in series) is replaced by a single Li-ion protected working between 3 and 4 battery , 2V (at 3.6V is 40% capacity).

The original battery, spare ref. 307132-001 HP is 500mAh, so a Li-ion 2600 mAh far exceeds that capacity, so it will retain more energy and for more years than the original having no "memory effect" (probably last longer the server itself), protecting better against unexpected power outages data (also recommended a UPS).