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.