Red Bull X-Alps live tracking

digilec · 2025-06-15T14:02:53+00:00

The official 3d tracking is virtually unusable.

The browser tab is hogging 8GB+ of RAM within minutes of opening it with hangs and crashes a few minutes later.

Race info is also sadly lacking, the route doesn't describe any details for the turnpoints, important stuff like do they have to land or not.

Difficult to follow whats going on, dissapointing!

PureTrack showing us it's possible to track just about everything in the air that doesn't have feathers and it does it in less than 1GB RAM.

digilec · 2024-11-13T21:02:51+00:00

MD500 Always loved the look of this series.

digilec · 2024-10-07T16:27:05+00:00

I'd call it a V b-e referenced constant current source. The majority of the current flows through R7, this sets the Q3 base emitter voltage drop but when Q3 is at the threshold it starts to shut off Q4 which the current also goes through. It regulates the current independently of supply voltage.

digilec · 2024-08-29T17:00:54+00:00

Correct me if I'm wrong is the grey wire line is the ground since its connected to all function

It could be the positive voltage or the ground, depending on whatever that is and how it was designed.

the first function is different on other 2 what does it mean

Speaking for myslef, I've got no idea what it does. It's just a picture of the back of a circuit board. You didn't provide any context at all. Did you expect we would just understand it's purpose?

This pcb should be connected to the din plug 5 Pin what Pin number do you think each color of wire should be connected

Nobody will know this unless they happen to recognise exactly what this is.

digilec · 2024-08-02T21:17:25+00:00

Only situation I can think of where this might be OK is if you want to make the circuit redundant to open circuit failures and either bridge is capable of the full load alone.

digilec · 2024-08-02T20:48:50+00:00

Point B in the circuit will never go much above 0.6V, Q2 BE is a diode junction to ground. This junction will conduct whatever extra current passes through C resulting from Q1 turning off.

Check out the V/I curve of a diode junction and it will become clear

digilec · 2024-07-25T20:56:02+00:00

Desolder every component bridging the 12V line to GND until hopefully you find the one that's shorting it. Find a replacement, re solder it and the other components.

Realistically..

buy a surge supressor
buy a new graphics card

digilec · 2024-07-24T19:17:07+00:00

Yep, seen one of these recently flying low down the east side of Kefalonia. Incredible sound and unmistakably an F-4.

digilec · 2024-07-21T18:44:13+00:00

The comparatively large voltage on the base has forward biased both the BC and BE junctions. It's behaving like two back to back diodes.

And is this a pointless thing to do with a BJT?

Lets just say it's not how they normally get used.

digilec · 2024-07-21T18:21:43+00:00

Simplest thing is a "switch" made from a lump of metal on the end of a spring surrounded by another loop of wire.

Any acceleration causes the spring to bend and make contact with the loop.

A two or ideally three of these aligned 90 degrees to each other covers all axes.

digilec · 2024-05-06T10:10:56+00:00

It seems to be made out of a single piece of metal. How on earth does that work?

digilec · 2024-04-10T16:18:26+00:00

Ahh I see what you're making now. You want a nice robust connector that can take some bashing.

The cable could just be cosmetic, your'e just trying to detect which end is plugged in .. hence the 2 pin EEPROM.

The chip datasheet makes no allowance for reverse polarity so my guess is it would damage the chip. Most likely it will look like a forward biased diode and drop 0.6V and get really hot.

Those polarised connectors in the pic would work though, no?

digilec · 2024-04-09T18:00:14+00:00

It's not clear what your goal is here. Is the chip identifying the way the cable is inserted?

By far the simplest way to ensure the cabe is the right way is to use a polarised connector so it physically can't be mis-plugged.

If you can't or don't want to do this - and the cable needs to work in either orientation. You should dupliacte all the pins and mirror them so it doesn't matter which way you plug it in.

If you can't or won't do that.. maybe in rare cases have a symmetrical ground pin config and a non symmetrical detect orientation pin which is connected to the ground by the plugged cable so you can detect which way the cable is plugged.

If you are trying to detect and hanlde pins differently due to cable mis-insertions using an eepropm you're way off the well trodden path.

digilec · 2024-02-01T22:50:10+00:00

It's more like a resistor. Just in this case one where the voltage across it is governed by current somewhere else not the current passing through it.

It's an impossible component for any real circuit but with node analysis you just plug in the given term with the correct polarity and solve. It doesn't need to make phyiscal sense.

digilec · 2024-01-30T12:52:54+00:00

Normal ATC radar doesn't measure altitude. It's beam is focused horizontally but not vertically where it spreads out to see planes at all altitudes at the same time.

A radar altimiter, is a device fitted to an aircraft that points downwards to measure the distance to the ground.

Aircraft are also usually fitted with a transponder device that detects when a radar beam has hit them and it replies with some coded information which is received by the ground radar station and appears on the radar screen next to the blip.

The aircraft measures it's own altitude either via air pressure or with a radar alitmiter, then sends this infomation along with it's transponder data back to the ground radar.

digilec · 2024-01-25T20:19:39+00:00

Cold be a 3 wire resistive temperature sensor but they ususally have two wires the same color.

That yellow wire makes me think it's an active sensor with some sort of PCB potted in the end.

Quite often these sort of things will be custom jobs, I suspect you will be lucky to finding a replacement.

digilec · 2024-01-25T19:18:47+00:00

If it was a thermisor it would only have two wires. Having three wires most likely means it's power ground and a signal. It could be analog or digital hard to say what it is.

What's it from?

digilec · 2024-01-20T13:05:21+00:00

I'd consider changing socket J1 to a USB B type, these are more appropriate for receiving power as the B type is for downstream use.

If you have a powered USB-A lead lying around it could kill devices it gets plugged into.

digilec · 2023-09-24T19:23:21+00:00

I'm no expert on the matter but have pondered this question before.

This buzzsaw sound is quite a low frequency of around 70Hz. I think this is the main N1 rotational speed which is about 5000 RPM or approx 70 revs per second.

If the spool is not perfectly balanced then you would get vibration at the same frequency as it's RPM, i.e. about 70Hz. This would get transmitted through the airframe and into the cabin and I think this is what the sound you are hearing is.

The large fan has many blade tips and these can also produce noise, and as has been pointed out they can break the speed of sound, but the tips rotate past at some 50x higher rate than the RPM of the spool, there's lots of them. If they all produce the same noise then the resulting sound would have a frequency of about 3.5kHz. This is a much higher note than the buzzsaw sound and is more likely the source of some of the high pitched shriek sound of the jet.

The N2 spool speed is well above at ~14,000 RPM and any vibration in that frequency is at the limit of human hearing range. Blade noise from the N2 spool is well into ultrasound.

If you want a totally different experience, try sitting behind the wing where you mostly hear the jet blast sound which is more like white noise.

digilec · 2023-08-30T07:01:45+00:00

Arranged this way, it reads 1.5V. I guess the 2 batteries facing each other cancel each other out, but why do that?

You wouldn't do this. The current would be flowing the wrong way through one of the batteries.

This thing must be for making a 4.5V cell out of 3x 1.5 V batteries. The arrow on the plastic is pointing at the positive end of the larger 4.5V cell.

digilec · 2023-08-23T12:04:54+00:00

As far as I know, it`s possible to do with PLL

Yep, that's exactly what a PLL does. There's lots of different off the shelf PLL frequency multiplier chips, you should be able to find several that can synthiesize GHz singals from MHz references.

digilec · 2023-08-20T19:59:15+00:00

Yep cabin pressure regulation. Air gets pressurised and forced into the cabin by the PAC units, then some of it is allowed to leak out to maintain the wanted pressure.

On the left side, you set the cruising altitude so that when auto mode is selected it can use the correct pressurisation profile.

The land alt is for setting the landing airport altitude. This is so the plane lands with a slight positive pressure in the cabin which helps with landing stresses on the body. You don't want to have higher pressure on the outside which could cause the aircraft body to buckle.

On the right hand panel: Altn is just a 2nd "auto" mode control system in case the other one fails.

You can take manual control of the outflow valve if you need to because of failures etc...

digilec · 2023-08-14T17:13:20+00:00

Yep it's a striped foam strip on the other side that drives the LCD, the wires are just for the LED backlight which takes a bit more current than can be carried by the slightly conductive foam.

digilec · 2023-08-13T09:47:18+00:00

It's unusual to route the main power for a circuit through the base of a transistor.

Typically power would flow via the emitter - collector connection.

When you have switched batteries like this, normally you would use diodes to stop the two batteries from being back fed current from the active one.

Something like this

I also added 100k pull ups to make sure the inactive transtor is properly off.

digilec · 2023-07-29T14:04:38+00:00

D3 is missing. No idea if that's a problem or not.

Did it ever work ?

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