Electric cabinet made out of parts from an analogue TV transmitter

We’ve been scrapping an old analogue transmitter at work, and I decided to recycle an old rack-mount chassis, as well as some other tit and tat, as an electrical box for the high-current DC parts of my solar system.

slskåpet1elskåpet4elskåpet3elskåpet2

Advertisements

Duct tape time for the camera remote!

I use a camera remote for most of my pictures. It is of course a DIY, and it’s made out of an old PS/2 mouse. It’s mighty handy, but I always disconnect it from the camera when I’m done, since it’d just be dangling off of the connector if I left it there.

The result of this is that I all to often can swear that I put it over there . . .

The solution is duct tape.

Step one.

Step two!

It’s madly practical, and it’s literally made out of four pieces of duct tape! What more could one ask for?

FF’s personal headlamp

This may not be what most people think about when they hear the phrase “personal headlamp”. I don’t blame them, as I don’t consider myself to be “most people” very often at all. In particular when it comes to mad, rushed electronics projects involving lead-acid batteries and duct tape.

The back story of this lovely piece of kit is that I, years ago (before I got myself a pocket-sized Dealextreme LED torch) too often found myself walking around in the dark Finnish winter with but a cell phone to light my way. A late night with plenty of coffee, tape, creativity and small lead-acid batteries at hand spawned this:

The first revision. Mid-2008, I think. EXIF data is since lost, but I'm quite certain that the picture is from 2009.

It consisted of a 21W bulb inside of the rotating armature (from one of those silly LED lights with a crank), as well as the three-position switch and 7 Ah 12 V battery that are still there in its current incarnation. It had one level of brightness and it served me well for a good while. However, once the bulb went bust last winter due to an incident involving a big dog, air travel and snow, I wanted more for this year. I wanted an H4 bulb.

H4s are lovely due to their flexibility: They have two filaments, which can easily be hooked up to run in series, as the following “pseudo-schematic” demonstrates:

Schematic over how my H4 bulb is hooked up

In a car, pin 3 is almost always ground. When you switch between low and high beams, you turn on one filament at a time. The main difference between the filaments is that the low beam filament has a bit of metal beside it, which prevents light from getting reflected straight ahead and into oncoming traffic.

In my application, however, I abuse the fact that the filaments share a common ground for the purpose of running them both at once and in series. By applying a voltage across terminals 1 and 2, I’m effectively halving the power dissipation of the bulb with no external circuitry. Since pin 1 is always ground, I can then run the high beam filament by simply switching my voltage source from pin 1 to pin 3.

It isn’t a particularly good solution, as the bulb is vastly less efficient at lower power; I’d get more light out of the 25-ish Watt it consumes by using a circuit to PWM one filament at 50% duty cycle. However, if I was to care about efficiency, I wouldn’t be using an incandescent bulb to begin with.

Here’s how the hook-up looks in practise:

Black is GND, red is VCC, yellow is high power, orange is low power.

With that out of the way, let’s get onto the actual building of the headlamp in its most recent incarnation! Some painstaking abuse of my side-cutters resulted in this:

It looks like the light is supposed to go behind it, doesn't it?

The holder for the bulb is made out of an old computer fan grille.

Some abuse of my fingers then resulted in this:

I don't know what I'd do without my red copper wire.

Low power mode, where both filaments are activated.

High power mode, where only the lower filament is activated.

A "normal" exposure of the light being on, low.

A "normal" exposure of the light being on, high.

The bulb I used for this has an extremely cool colour temperature. The white balance I use for these photos is set for my 600W halogen flood light, which I consider to already be quite cool. This little 60W bulb still trumps it in that regard. I was actually fairly surprised at how white the bulb is, as the battery voltage drops to well below 12 V when using one filament.

So, that’s the story on my headlamp. It’s incredibly inefficient, not particularly durable, very heavy and ugly beyond belief, but it’s saved my butt more times than I can count. While my little LED torch is fine for most things, you can’t just put it down on a table and expect its little focused optics to light up a room properly. It also makes cars turn their high beams off for me at night, and I can even return the favour!

It looks a lot better in real life, as the filaments fade down over about a second after it's turned off.

Super Flower Golden Green Pro – Part 2

A sad sight indeed.

Pictured above is how my poor computer has been running since a couple of months back, when my old Corsair HX520 bit the dust. The ARENA PSU is at least a Chieftec on the inside, at least.

MOLEX connectors are the best.

My graphics card got its power through a fan adapter AND a PCI-E adapter!

Sparing you a build montage, poof!

One could argue the sensibility "two PCI-E connectors on one cable" design.

The cable sleeving is quite nice for routing on this PSU. They’ve used some form of flat sleeve, so the cables are quite easy to route around thin areas within the case.

A small detail, but I find it noteworthy.

Of course, while disassembling my computer, I can’t just replace a part and leave it at that, no Siree! Some improvements to the case:

I never understood the point of internal fan grilles.

I think that looks beautiful, don't you?

The reason for the duct tape is that whoever designed the fan grille for the plastic front of this case didn’t do a very good job. A fourth of the fan is simply covered up by plastic, whilst a fourth of the filter has no fan behind it. The duct tape is installed in a way which seals the whole unused HDD bay off from the rest of the computer, with the exception of the holes that the fan covers. This allows for a considerably larger area of the fan filter to have air flowing through it at a more even spread. This should both allow less dust into the computer, and allow for more throughput at the same time.

Oh, and the fan being placed closer to the graphics card helps remedy this.

There is a small . . . flaw, with the Arctic Cooling Accelero GTX Pro (aside from its name), and that is that that they didn’t quite consider the amount of heat that was generated by the VRM of the GTX260 c216. Without some extra heatsinks stuck on top of the PCB and a fan pointing directly at the card, they will simply overheat. 145°C seems to be as high as they’ll run without causing issues. By moving the fan and creating the “pressure chamber” out of my HDD bay, the FURMARK temperature of phase 3 dropped to below 120°C!

Being made in Switzerland does sound nice

Two out of three, at least.

I can’t say that I’m particularly satisfied with the cooler overall. The fans are rather noisy, and at very low speed, the above happens.

The power supply considerably reduced the power consumption of the computer.

Testing everything out, the Super Flower does deliver! This computer would consume well over 400W when loaded down similarly and running on my ancient HX520. It is quiet in both electrical and mechanical noise, the fan controller follows a nice speed-to-temperature curve, and it even has that RELAY that’ll go click when you turn it on or off. Lovely!

In conclusion, I have a strong feeling of this being a worthwhile purchase, and as of now, I can’t do anything but recommend it. It’s too early to tell if it’s going to last or not, but the signs are very good indeed.

For those who care, I’ll close with the specifications of the computer:

  • CPU: Intel Core 2 Duo E7400 (3.8GHz/1.35V)
  • CPU cooler: Xigmatek HDT-1283 (Noctua NF-S12B rear case, NF-P12 front case)
  • Motherboard: ASUS P5Q Pro
  • GPU: Nvidia Geforce GTX260 c216, 896MB (Slightly over-clocked)
  • GPU: Nvidia Geforce 8400GS
  • RAM: 4GB DDR2
  • HDD: 320GB Samsung Spinpoint F1
  • Sound card: ASUS Xonar DX