landimatteo

does the UPS just suddenly shut-off cutting the power to the loads or somehow make the loads shut down themselves?Anyway maybe the working time is preset considereing the capacity of the original built-in battery and it's not based on the actual charge or voltage.If it's that the case it's hard to tell if you can do anything about... maybe bypassing the line between the logic and the relay.

as pure speculation I can say that probably there is some sort of "logic" unit comparing the power load to the threshold and counting the 5 minutes and then turning off the power, and probably the UPS runs until a specific output of that unit is high(for example 5V or 12V) so you can try few alternative strategies:1)trick the unit to believe there is a higher load to avoid the shut down2)prevent the unit from being able to shut down the ups(for example connecting a 5V or 12V to the unit's output such that is always "high")3)another possibility is, in case the timer is represented by a monostable circuit(the same kind used for lights that automatically switch off after few minutes in garages, stairs, toilets), to trick the "timer" to get the shut down time as …

as pure speculation I can say that probably there is some sort of "logic" unit comparing the power load to the threshold and counting the 5 minutes and then turning off the power, and probably the UPS runs until a specific output of that unit is high(for example 5V or 12V) so you can try few alternative strategies:1)trick the unit to believe there is a higher load to avoid the shut down2)prevent the unit from being able to shut down the ups(for example connecting a 5V or 12V to the unit's output such that is always "high")3)another possibility is, in case the timer is represented by a monostable circuit(the same kind used for lights that automatically switch off after few minutes in garages, stairs, toilets), to trick the "timer" to get the shut down time as long as you want. This kind of circuit maybe is implemented with a 555 IC, and in this case the interval is determined by the values of an external resistor and an external capacitor ( T(s)=R(ohm) x C(farad) )....therefore if you understand how it works you can replace the capacitor and/or the resistor to extend the working period

As I already I'm an aerospace engineer and I'm aware of that to be a measure you can trust it would require much more attention to pitot placement and calibration, and that in general airspeed is not a good measure of ground speed in case of wind. So this is not something to be intended as a measure to rely on for example to respect speed limits. My primary goal was exacly to place this system in my car so I could drive at a known speed (for example 90 km/h according to speedometer / smartphone GPS) and read the related airspeed measure in a day with no wind at all (where I live, except for occasional storms, wind is extremely rare, especially in winter and summer).Unfortunately I have no avaiable any CFD simulation of the aerodynamic of my car model but anyway from other simulations rang…

As I already I'm an aerospace engineer and I'm aware of that to be a measure you can trust it would require much more attention to pitot placement and calibration, and that in general airspeed is not a good measure of ground speed in case of wind. So this is not something to be intended as a measure to rely on for example to respect speed limits. My primary goal was exacly to place this system in my car so I could drive at a known speed (for example 90 km/h according to speedometer / smartphone GPS) and read the related airspeed measure in a day with no wind at all (where I live, except for occasional storms, wind is extremely rare, especially in winter and summer).Unfortunately I have no avaiable any CFD simulation of the aerodynamic of my car model but anyway from other simulations ranging from racecars to off-road ( http://ww1.prweb.com/prfiles/2009/01/20/1126544/J... ) , including similar stationwagon designs, the flow on the hood(at least the ones with no bumps like some muscle cars) is consistently laminar.In addition as you can see the normalized pressure on the hood usually range from pressure higher(red/orange/yellow) than undisturbed flow (for example close to a steep windshield) to pressure lower(blue/cyan) than undisturbed flow (for example near the front end of flat hoods). Flow continuity implies that somewhere in between those 2 regions there must be a region with conditions equivalent to undisturbed flow and this is very convenient.

Yes, I remember I used that in a windtunnel at university (I'm an aerospace engineer) and basically I included them in "other differential pressure sensors" including the aneroid based mechanical ones, the fluid(water,mercury) ones, the various electric/electronic ones (piezo-resistive, LVDT, capacitive, etc).The U pipe is really easy to make but quite hard to read, especially while driving the car, and especially if the speed is not constant(you have to measure the difference in height of the fluid free surfaces, one going up and the other down, so you can't even use a fix graduation since the 0 is the free surface of the fluid that is constantly changing) and is also affected by accelerations(turns/acceleration/braking) and non-flat road surface.

There are ways to get your hands on them, for example (not necessarily the best way) http://www.ebay.com/bhp/airspeed-indicatorAnyway let me give you a suggestion: "Cool" planes are usually faster, and faster planes need airspeed indicators with a wider scale (for example mine has a scale 40-260 kn, maybe from the "cool" SIAI-Marchetti SF-260). But driving a car, unless you have a very fast car you would barely reach 90-100 kn (assuming you are allowed to drive that fast). Here (Italy) unless I go to a race track I'm limited by the speed limit of 130 km/h (about 70 kn) on the controlled-access highway. therefore more than 3/4 of the scale is useless to me, (and about half of the car speed range is lower than the minimum). Something from/for Ultralight would be better …

There are ways to get your hands on them, for example (not necessarily the best way) http://www.ebay.com/bhp/airspeed-indicatorAnyway let me give you a suggestion: "Cool" planes are usually faster, and faster planes need airspeed indicators with a wider scale (for example mine has a scale 40-260 kn, maybe from the "cool" SIAI-Marchetti SF-260). But driving a car, unless you have a very fast car you would barely reach 90-100 kn (assuming you are allowed to drive that fast). Here (Italy) unless I go to a race track I'm limited by the speed limit of 130 km/h (about 70 kn) on the controlled-access highway. therefore more than 3/4 of the scale is useless to me, (and about half of the car speed range is lower than the minimum). Something from/for Ultralight would be better because of the lower speed (something like 20-120 kn would work much better) and because without certifications even a brand new instrument would be much more affordable.

...by the way, As soon as you have done, don't forget to come back and leave a comment to let me see your results

Of course in an exam with limited time and a lot to do I would not exchange my scientific calculator for this. But in other situations I feel like I could be a valid alternative. I tried to re-do some basic exercises about heat transfer by radiation, space propulsion, etc. I can still solve them with this, although much slower.

If you can't find your old one, or just want to leave a more "expendable" one in his hands to let him practice, I hope this represents a cheap and viable alternative.

Thank you for your comment. :-D I was actually expecting more articulate comment (expecially since I was expecting a lot of viewers being engineers). But making viewers amazed and worldless is still satisfying.

I'm sorry but I don't know the webcam model. The brand is wimitech (a supercheap chinese-store brand) and I had bought this camera many years ago(I have no more the packaging/manual) and I can not find it online(the image with the blue webcam is identical to my model). anyway any webcam with the ability to be focused manually should work if you focus properly.

Instead of building a new reflector I used a disposable cake plate I had avaiable. The light source is an IKEA JANSJÖ LED spotlight on the left and the reflector is placed on the rightI shot an airplane model with and without the reflector.

Well this specific pole/monopod was homebuilt by me and was ready about a week before this festival, I used it for pole photography (reaching about 4 meters) of a small church in the days before the festival but never before as a monopod. In the past I used another homemade monopod (from a telescopic walking stick) for taking pictures at rugby matches and airshows

At the end of a streetpainting festival in front of the santuary at late evening.The camera was mounted on a 3-sections monopod/pole I used to capture the large paintings on the tarmac orthogonally. At the end of the day I removed the central section and used it as a monopod to get a more stable shot of the square and church front. The shutter speed was quite short and ISO high anyway because I didn't wanted the people passing by to be blurred

The bird's eye is shot at night (4 AM) during a streetpainter's festival, using a D3300 mounted on a 3 meter pole and pointing down.

It was actually a heavy storm at dusk, this might explain the weird effects.

Neutral, tilted up, tilted down ( almost bird's eye), side swing

Nikon D3300

Thank you. Yes, I had the same impression being this perspective usually used as a trick to make scaled models appear bigger than they are, and I liked this because that airplane was so perfect in every detail that looked somehow unreal even in real life and make it look like a model in a diorama was a great effect, to be fair I was not aware or conscious of this effect when I took the picture.I'm using a Nikon D3300 with a 18-70 lens

I went to an airshow of vintage aircrafts in northern Italy. This is a "Stearman" on the field just before the engine was started for the display. The picture is taken with the camera at "grass-level" on a small tripod to clear the background from the "disturbances" caused by people and other aircrafts and let the yellow airplane really stand out on a clean background.

Thank you. Anyway the pattern is expressed in centimeters. It was specified in a note inside the image but maybe on mobile devices you can't see the note.

Thank you. Anyway the pattern is expressed in centimeters. It was specified in a note inside the image but maybe on mobile devices you can't see the note.

thank you