16 October, 2015

Fuel economy in a car: Charging battery the Arduino way: 2nd and last part

26650 LifePo4 A123 batteries (2.3 Ah)
After analyzing the advantages and disadvantages of changing the car battery for a homemade LiFePo4 one as we discussedI've finally discharged it for the following reasons :

04 September, 2015

Home Automation: How to activate a relay via USB on Windows to control devices (blinds, lights, etc)



Although it is most economic and versatile use Arduino as a programmable electronic board, so we avoid the known unreliability of Windows, when you want to activate a equipment is sometimes easier to use a USB relay, either because we have a computer that has to be always on, or for other reasons, allowing us to theoretically control up to 8 switches for each USB connector on the same PC. 
I had to replace an old system that used the LPT1 port for controlling a time alarm (not compatible with Win XP or 7) so after investigating it I bought 2 pcs. of this USB-controlled relay  in Aliexpress.

And if we want to control multiple devices there are up to 8 channels (relays) in the same unit, with each relay 10A capacity, so the possibilities are very extended.




22 August, 2015

Fuel economy in a car: Charging the battery the Arduino way - Part One


In this post we will see what details we consider to adapt a vehicle to save fuel by switching off the alternator when we are not interested to charge the battery (and take advantage of braking, engine braking, etc. to do so), taking advantage of lessons learned in the previous post . This It is especially useful in a diesel , where power consumption is much lower than in a gasoline car.

Currently any measure is little to lower the consumption of a car, and although we are in a period of decline in fuel prices, this is transitory, because as with any commodity product high demand prices will soon go back up (or keep at the highest possible price that permits its competitors).
We can change the wheels to a eco profile ones, change the oil by other more energy efficient (as we discussed), etc. And one of the points of great savings capacity (between 1 and 5% savings) is in producing electricity, generating electricity with oil is very expensive. Some people even partially hybridized vehicle for changing the alternator motor / generator and replacing the battery with a LifePo4 (Forum GoldenMotor).
You have to evaluate the suitability of this modification, as the lead-calcium batteries do not allow more than 20% discharge without damage, so there is little room to use them with a programmed charging. Ideally mount a LiFePo4 battery, but can cost more than 200 €, only useful and profitable to people that uses them a lot in short travels in the city (taxi drivers and transport vehicles).
The most innovative engines are now including programmed battery charging, so that is only activated when the low voltage level is reached, although I do not know what kind of battery this cars uses and what the procedure in detail.

Curiously, in the following video you can see how the workload on the alternator note clearly appreciate the drop in rpm (and automatic adjustment by the control unit) of this PSA 1.6 HDI diesel engine:


21 July, 2015

The Li-ion 18650 for sale on the Internet: There are more false than legitimate



When I started acquiring Li-ion batteries 18650 back in 2012 to restore some packs, there were still no stores in Spain that had them and I started to import them through Chinese pages like DX.com, aliexpress, Ebay, etc.
Note: The reference "18650" refers to the shape and dimensions; 18 is the diameter in mm, 65 is length and 0 indicates the shape; in this case cylindrical.
At first I was confident and I trusted the ads in some extent, I knew the false capacities of some NI-MH before, where manufacturers also indicated many times more capacity than real, so I was prepared. I compared, and bought cheap, but not the cheapest, high capacity (announced) batteries, , and hoped that there would not be much difference.
This problem is very well explained in Energizes or Bateriasdelitio.net , which echo the deceptions of Chinese "smart" guys.
I was wrong. I came to ordering (ouch!) For 3 €/unit. 18 batteries "Fandy-FIRE", the "manufacturer" marked them as 3600 mAh capacity, when in fact they only had 800 or less! When they arrived the first thing that struck me was how little weighed; the larger capacity usually weigh 47 grams / unit, when these did not reach the 30 g / pc., although some manufacturers are "approaching" the weight of the good ones filling them with materials as diverse as flour!

20 July, 2015

Current state of the art LED options in H4 / H1 car bulbs

Model H4 LED high performance
Tired of changing the H4 halogen lamps of my Xsara Picasso car, I was looking for alternatives in LED, checking the state-of-the-art in H4 Led lamps, If I could find one well worth installing, so getting savings in fuel and maintenance .
Is it legal? : To carry LED lamps  outdoor legally in Spain, for now we only have the option of installing a complete approved headlamp, and that must be installed by a certified workshop to carry the certificate to the periodic Technical inspection, because the headlamps are designed for a type of lamps with which it lights the same way (lumens and openness); this could cost easily €150. These lamps in theory can not be used on public roads (although for racing/testing purposes). There is no problem changing the ambiental interior lights to Led ones.
In the following video I commented highlight of these LED lamps H4 "SunnyLight"  and installation:


18 July, 2015

DIY: Turn your bike into e-bike for yourself - Step 5/5: Final details: Active Braking, charge control and legality

This wounded wire is my brake;)
After a few months of using battery-powered bike, I am going to comment how it feels. On the one hand it does very well with the uphills, but the downhills are another thing. In my neighborhood we have slopes with between 8 and 10% drop, and the bike does not stop fast enough with his brakes (disk brake only in the back). I have found that its weight (about 30 kg) is a major handicap, and although putting many banks in each cell increases the li-ion battery life and autonomy, it makes very difficult to go upstairs with it (impossible to carry on daily to an apartment), or braking, the brakes suffer a lot (especially at low speeds when the engine brake don't work).
Although we could use engine braking to stop and derive the energy to the battery, but you can not raise too much the regeneration (engine braking); above 15 amperes (1,5C) batteries suffer much from excessive current (even without reaching 4.2V per cell), and they degrade faster, besides the Golden Motor control is proportional to speed (recovers more amperes the higher the speed), so we could be sending a damaging 40A to the batteries if the slope is steep and we go fast.
Another option is to put LiFePo4 batteries, much more tolerant, but they have less energy capacity per kg, in addition to its high prices. The A123 for example accept for each 26650 cell type up to 10A continuous recharge. For this moment I can' afford them (although they come equally profitable having more recharging cycles).
After investigating, found a interesting solution  about using a resistance as a powerful engine braking (what  a great well of wisdom is Endless Sphere about electric behicles), ¡and they have proved that it works wonderfully!:

Example of resistance brake on a bike from a friend of Endless

15 July, 2015

Changing the hard drive of a Lacie Network Space 2

A couple of years ago I bought this super NAS (Network Storage) Lacie with Linux operating system, good performance and very low power consumption (you can set it to shut off at 20 min. without use, very convenient for longer life of your hard drive).

The disc It had got too small, so using Clonezilla, I opened the box (to do only handle in the area led out all the cover up), and I cloned the 1TB disk to another larger than 2 TB. To exploit its full capacity, we have to resize the XFS partition data to use all the free space remaining with the Gparted (free Linux program).

The Gparted allows us to do all sorts of operations on partitions (image of their web)

13 July, 2015

Avoid the discharge of the car battery when not used using a simple relay and interruptor

Relay connection scheme
An old Fiat Bravo was draining battery when not used for a couple of days, and the battery had to be recharged every time: The electronics had an excess of consumption, far surpassed the admissible 0.3 Amps.
After reviewing the possible cause (alternator regulator in poor condition, or something that was connected) by removing fuses and checking consumption every time, I did not found the source of the problem, so we decided to place a switch controlling a relay to disconnect the battery when the car was not in use.
Thus the battery, although the car is not used for 1 full year, only 30-40% is discharged (typical self-discharge at 1 year for batteries Pb / Calcium). Furthermore we lengthen the life of the Central Computer by completely disconnecting it. 
I also take the opportunity to see how these relays are for my next project, which would be programmatically control the battery charging to save fuel by turning off the alternator.
NOTE : Keep in mind that if the battery gets disconnected, you lose the date and time of the control panel (if any).

Using a relay just have to carry three thin wires into the cabin to turn the switch and voltage indicator, because power is handled as close to the battery as possible.

24 June, 2015

DIY Homemade pool water solar preheating system - by Jordi

Economic system of heating pool water
This past summer Jordi from Valencia was consulting on how to heat the pool water with economic polyethylene tube, and discussing their results, and is happy to share it with you.

Surely he noticed this post (system that does not use nearly as efficient) and was encouraged to heat his pool that way, and wanted to "removing the cold", raising its temperature from 18 to 25, a more comfortable temperature, taking advantage of the close roof surface where the sun hits well.

Jordi told me that he would use PE pipe Ø20 mm. and had doubts if it would work; the pool is quite large , 14x3 meters. I had thought to extend about 250 meters tube had calculated that fit on the roof.

17 June, 2015

Lighting by electromagnetic induction: Current best choice for high power lamps


When it is necessary to illuminate a street, building, etc, and lots of light output is required, induction lamps are more profitable than the LED because of its lower price and its durability.

Campana 250W used in warehouse
Key Features:

10 June, 2015

Connecting an IDE (DVD-ROM, HD, etc) unit to a motherboard without IDE port (SATAS only)

Using an IDE-USB adapter we could "recycle" the IDE recorder
In many current motherboards like Gigabyte GA-F2A55M-DS2, no longer include IDE ports , which have been displaced for speed and economy by SATA. 
But if we have such an old IDE DVD Burner 3.5" and we want to continue using it (it is not the time to pull something that works), we can be forced to pay more for a motherboard with those ports, or instead we can place a IDE to USB adapter that functionality allowing us permanently for 4 € (saving us 30 € that costs a new DVD recorder).

As we saw in a previous post , adapters SATA / IDE to USB are very practical; it specifically has to IDE 3.5 "and 2.5" SATA port, very useful when you need to connect hard drives without opening the computer:

You can buy on Ebay from 3.99 shipping included in Spain

We just need build or search for a USB connector on motherboard, which I believe to be the most difficult part (although you can use a box of a PC to go to waste); I for example have obtained one cutting the Firewire 1394 connections (in the first picture the gray cables cut) not be used for anything, and solder the red, white, green and black USB adapter cable at positions corresponding to leave permanently connected to the motherboard:


In the picture below, the adapter connected and working, although I had to remove a lateral from the connector for the power supply on the left:


04 June, 2015

Computer with dropbox slows: Usage Tips


I recently repaired a computer that "slowed down" a lot to boot. It was a laptop with Celeron, quite outdated already. What was my surprise that the cause that produced this problem was they had shared a folder several gigabytes of information in Dropbox  (videos and photos on vacation)  and not a virus; the users wanted to backup everything in the cloud, so that every time Dropbox was checking changes, the hard drive was "going crazy".

28 April, 2015

The plotter fails to recognize the cartridge: Repairing a 500-800 HP Designjet 42 "


We had a problem with our plotter; it marked "unrecognized cartridge" error before finishing of each printed plan; when we repositioned the cartridge the problem was solved for a while, but it seemed a problem of poor contact with the cartridge chip (it was produced when the motor axis ink supply was activated).

To repair it, you have to access the module cartridges; first of all we need to remove the cover of Control, it is a matter of finding and removing all the screws, simple task and which information is on the internet, so that I refrain from commenting;)

26 April, 2015

Turn off RadioCD in a Xsara Picasso car: Connection to the burner

We dropped the front screws and side to find the lighter wiring
RadioCD included by factory in the Citroen Xsara Picasso does not disconnected immediately after removing the key, so remains on a couple of minutes after the unit is disconnected.
In this case it is advisable to connect the red wire RadioCD "ON" (not the one going to the battery, but the activator) to positive cable of the burner, and then this hassle is avoided.

15 April, 2015

In Depth: Lexman 9W LED bulb E27 230V 4000K 806 lm of Leroy Merlin

In my case gets 3 years warranty

LED bulbs are already flooding the domestic market, with options for almost every need.

We will analyze in detail a model that sells E27 Leroy Merlin with 3 years warranty brand Lexman  (non-publicizing, just to compare).

This bulb shines very well, with a more than acceptable theoretical efficiency of  90 lumens/W, perfect for replacing incandescent bulbs of 100W  (tested). 
His tone, a clear yellowish 4000º Kelvin, is suitable for everywhere in the house (although it is away from 5600K natural sunlight, colder), and a higher CRI of 80, enough.

If we break the glass we see that the controller gives 94V, feeding 33 LEDS 3528 series (which theoretically receive 2,84V and 0,27W each emitting 24 lm / ud), giving 806 lumens and 9W according to manufacturer (and although I can not measure it, seems to be true from its luminance):



The design to dissipate heat is of lightweight aluminum inside, which contacts the exterior part thermal plastic, that transfer worse the heat than aluminum, so it does not burn and can be touched, but it would be best if it were metal body such as lamps from Ikea, since the chip area after 6 minutes is at 43 ° C with 18ºC environment temp.:

With the (+ - 1 ° C) temperature sensor check infrared LEDs

and reaching 64 ° C! after half an hour, a temperature not very convenient for semiconductors. The manufacturer indicates a lifespan of 15,000 hours, but I hardly trust it, I recommend saving the invoice and not buying this bulbs because, if we use a lot, It will not reach the three years guaranteed!

Anyway, for € 6 per bulb, and for environments such as the bathroom where they are at most one hour on, they are more than recommended. For other uses, best to get better quality lamps.

01 April, 2015

Preparing a ventilated protective mask for Airsoft

Homemade ventilation mask

Eye protection is mandatory in airsoft, but most masks do not have enough ventilation, so you end up with very low vision by condensation on the policarbonate plastic.

As others have done before methe trick is to introduce fresh air with a small fan and battery; I used a fan from a notebook computer, with a small switch and a 18650 lithium battery (4.2V) in the corresponding adapter .

27 March, 2015

Repairing an old Mitutoyo profilometer probe


Some time ago I repaired an old Mitutoyo profilometer 178-928D , which no longer has spares and which had broken the pin that transmits motion to the head holder; a calibrated shaft that moves left and right and which I hold in the following image (the pin / screw was in the center hole):


This probe has a very simple operation. The spindle that is coupled detects changes in a very similar way that is translated the marks in an old LP music disk, transmiting the movements caused by the roughness by a magnet and coil needle.
The shaft that moves the spindle is moved in a controlled manner with a step by step motor to an endless spindle, first the engine slowly forward in the measurement phase, and then quickly picking head to its starting position, all controlled from the profilometer which is connected with a cable with 6 wires (that is a seven or eight cable, but one or two are not used, as you can see in the following images after repairing the cable too):

09 March, 2015

Repairing a tape backup LTO 2 unit: HP Ultrium 448 with broken tape


In a unit Ultrium Fujitsu (HP) for backup, the tape had broken, being useless as the mechanism for capturing the tape was inside it. To repair the unit is complicated, recommended only to those who have already dealt above with similar mechanisms (VHS, glory times). 
To repair it is necessary to understand the method these units use (and many other models are based on the same principle), a curious way to save space by having a single drum in the cartridge and in the unit, where the tape passes from one side to another as information is stored, until it ends.
These LTO (Linear Tape Open) are optimized for capacity, and the latest versions, able to store 2.5TB of information in one cartridge that costs about 20 €, making it very competitive in terms of price and space currently.
After this brief introduction, let's go to the subject.

10 February, 2015

6 tips to save on your vehicle maintenance


Today, thanks to the internet we have plenty of advices and hints to save maintaining our vehicle, we have plenty of tutorials for whom are a little handyman; from changing lamps, brushes, etc to oil changes, and some dare to change pads and cushions. After years of use with my Xsara Picasso, I share with you the ideas and optimizations that can be applied to your vehicle to save money, helping the nature too.

1. Change the rubber instead of the entire windshield wiper

Change only the rubber and be ecofriendly

09 February, 2015

Repairing and Adflo Speedglas battery ref 837621 with LI-ION 4.2V Cells


Lately I have been repairing multiple wireless devices whose NI-MH batteries have deteriorated ; usually get considerably cheaper make you the battery pack with a new charger is to buy it new; in this tutorial I will show how to build a battery of 4500 mAh 12.6V and 3 packs of 3 cell li-ion parallel each to replace a battery 10.8V and 4000 mAh NI-MH (9 batteries in series 1.2V) with just 32 € (charger not included).

LITHIUM battery types depending on their composition

The Lithium-ION technology has improved a lot as  the advantages of having no memory effect and higher energy density per kilogram than any other current technology , we can add that  depending on the type of materials used , allows different power / energy densities; we can have instantaneous powers from 1C (2A / time to a cell 2000 mAh) of the LI-Cobalt portable typical 5C of manganese (LiNiMnCoO2) or 15C for the past employed in Automobiles (LiNiCoAlO2) or 30C with LiFePO4 .

Modifying an airsoft HK 416 UMAREX with 11,1V for increased rate of fire: from 13 bps to 18 bps

HK 416 from UMAREX, very high quality materials and precision
Recently I personalized with more cadence one airsoft replica HK 416 from UMAREX, the best available today replica of the lethal original, getting to shoot 18 balls per second instead of 13 with the recommended battery.
For this we have got 11,1V instead of the 7.4V li-ion recommended by the manufacturer, using 6 standard size batteries 2000 mAh 18650 and 1C discharge . Usually LiPo is more desirable for these cases, for the effort that must hold the batteries, they probably will last less than normal ... but what can we do... life is short;) and we just had them available.
Putting 11,1V to the repeater you are breaking the guarantee, but it have such good material and design that we'd rather risk getting a machine of epic massacres;)
In the following video a Youtube friend did the same and is working very well:

08 February, 2015

How works an electric cooler: Cell peltier

We pack a cooler for the curious

Well, after a temporadilla almost no entries, I think this summer will not you going to complain;.)We'll start with this entry, in which he disarmed a cooler of those that plug into the car (or home if you adapt one transformer least 5 amps and 12 volts), to discover another fascinating use of semiconductors (thermoelectric effect) and electricity: The Peltier cells .




07 February, 2015

Replace magnesium sacrifice anode in hot water tank by yourself


After four years working properly, it is time to do the maintenance of DHW storage tank from the solar thermal collector  changing the magnesium anode which prevents the deposition of oxide by galvanic protection .
Sacrificial anodes will last more or less depending on tank size and the degree of degradation thereof , that is; if you have many areas without paint, he's paid to oxidation and anode (magnesium in this case) will provide more ions, degrading its structure more quickly.
First of all, we acquired a couple of sacrificial anodes, are cheap, about 15 € each (I ordered them on Ebay for a company of Madrid). To change it, release the cover ( IMPORTANT empty it first ), loosen all the lime and use mud accumulated over the years:

06 February, 2015

Repair of electronic tracks on an old keyboard: Conductive silver liquid

In this post we will repair CNC keyboard that is no longer being manufactured
Contacts on the keyboards have evolved from mechanical systems to more modern with membrane. In this case we will repair an intermediate type; this keyboard from a Gemini 8050T FAGOR around 15 years old carries a screen printed aluminum membrane for tracks and graphite contacts, on which a metal piece with flexible concave shape closes the contact when pressed.
The technology of switches on keyboards usually are of two types: contact , where some kind of spring (metal or plastic or flexible rubber, etc) keeps separate tracks of the conductive surface (graphite or other) of the button, which when pressed blend tracks; and secondly, the induction, where pressing the button, a small magnet creates a small electrical pulse in the coil of the membrane (ultra durable modern musical keyboards).
Repairing first type of keyboards often requires all your ability of "handyman"; some with copper tracks like TV remotes are often easier to repair welding on the tracks a small micro-switch if the button is completely useless, but most cases are plastic membranes that can not be welded and we can use either glue threads on them as in this entry, or use the useful liquid silver, and you will always get a more professional work to build the appropriate cable connections.

Equipment needed

  1. Cutter to open the damaged contact (in other keyboards will not be necessary).
  2. Cleaning liquid or solvent which does not attack the material of the keyboard; I used Ardrox 9PR5 or you could use isopropyl alcohol.
  3. Liquid silver conductive, with which "will draw" deleted / damaged tracks with a fine brush after cleaning them well.
  4. A tester to verify that the track drawn conducts electricity.
  5. Scissors, PVC tape to cover the contact again, brush, permanent marker to draw the button again, etc.