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106  Forum 2005-2010 (read only) / Bar Sport / Re: Proof of concept on: July 23, 2009, 09:56:48 am
Is there any automation in the system to start with, or is ticketing all done manually?

Washington, DC has had a RFID pass system for a few years now, which works exactly as you described--the pass is scanned on entry into a station, and when you exit your fare is calculated based on origin and destination and deducted from your balance.  There are machines in each station that can read and add to that balance with cash or credit cards.  

Of course, there was already an electronic farecard system in place using paper magstrip cards with electronically controlled gates, so the infrastructure for it didn't have to be built up from nothing.

Google tells me that 10,000,000 forints is equivalent to about US$52,000 which doesn't sound too unreasonable at all if it means a lot of new infrastructure.  Remember that it's not just developing the technology (like you said, that part is easy), but also taking a thorough look at staffing costs, customer impact, transaction timing, etc.  Those need to be evaluated LONG before you start rolling out something like this.  

What happens if you roll out a shiny new RFID pass system only to discover that station uplinks are too slow, or your central server can't handle the peak load, and your customers are standing there waiting three seconds for their cards to be validated before the gate opens at rush hour?  I don't know about the transit system in question, but I can tell you with full certainty that that kind of delay on every transaction would be disastrous at rush hour in DC.
107  Forum 2005-2010 (read only) / Bar Sport / Re: Somedays... on: July 25, 2009, 11:14:31 pm
Brilliant.

Reminds me a bit of Arthur Ganson's work: http://www.ted.com/talks/arthur_ganson_makes_moving_sculpture.html
108  Forum 2005-2010 (read only) / Bar Sport / Re: Have to get this out... on: July 16, 2009, 02:42:55 pm
Unless you've got a wiring problem, the servos are probably the only things putting a significant load on the supply, can you disconnect them and then run the sketch to see if it still resets?  It could also be a software problem (overrunning the end of an array or somesuch, for instance).
109  Forum 2005-2010 (read only) / Bar Sport / Re: Have to get this out... on: July 16, 2009, 12:18:55 pm
I don't think I've ever personally blown up an LED, but a few projects ago I set an employee to building a bunch of LED pairs on long wire tails that were to be installed in some scenery, and then went and worked on something else.  I came back later to a nasty smell and a bewildered employee who, come to find out, had put mains plugs on the other ends of all of the tails (they normally only deal with mains equipment), and then plugged one of the pairs into the wall to "test" it.  At that point I indicated the batch of 6V wallwarts that had been purchased for the job, and the employee had an "aha!" moment.

My most common problem when I get tired seems to be forgetting to change the mode on my DMM when changing measurements.  Fortunately, my bench supply has gracefully withstood my inadvertently measuring its short-circuit current more than once. . .
110  Forum 2005-2010 (read only) / Bar Sport / Re: Mysterious transformer? - picture puzzle on: June 14, 2009, 01:26:56 pm
230V, 50Hz in all likelihood means that the primary side is meant to be fed 230V @ 50Hz (although 60Hz won't do any damage).  The two red wires are for the primary, and the three QC terminals are for a center-tapped secondary (which means the transformer will output 0V on one contact, +V on one, and -V on the other--whatever V happens to be).

If you're feeling adventurous*, wire up the two red wires to a 230VAC supply, and meter the three QC terminals to identify the output voltage.  

Of course, you'll still have no idea what the rated current is, so the utility will still be rather limited--not to mention the fact that for any application that would require a transformer this beefy you'd be much better off with a lighter, more efficient switch mode power supply (like you'd find in a computer, for instance).  So really, this thing isn't likely to be very useful for anything aside from keeping your work bench from blowing away.  

*Obviously great care should be taken, and you do everything solely at your own risk.  This entire post is based on conjecture and educated guesses, so it could be entirely wrong if the transformer turns out to be a real oddball.
111  Forum 2005-2010 (read only) / Bar Sport / Re: Liquor + Arduino = need a pointer or two on: June 09, 2009, 10:01:58 pm
Unistrut is another option.  Cheaper than the fancy aluminum extrusions and often available at your local hardware supplier.
112  Forum 2005-2010 (read only) / Bar Sport / Re: Fluorescent light dimmer: it's that possible? on: June 09, 2009, 09:56:27 pm
You'll have better luck with microcontroller-based dimmers than the simple R-C-Triac based ones like you find in the walls of most homes for starters.  The current/voltage phase shift caused by non-linear loads like fluorescent lights can mess with the zero-crossing detection of the latter and cause problems (although adding a dummy load, like a few incandescent lamps, in parallel with the fluorescent fixture can help).

Best bet is a properly-wired dimmable ballast like BroHogan suggests, although FWIW I've been able to get some dimming range even with non-dimmable ballasts on ETC's Sensor+ family systems, but that might be a bit overkill for your application smiley.   You will never get a smooth 0->100% dimming, though, even with the best ballasts and dimmers.  Best case, you get something like off,40%->100%.
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