Search found 87 matches
- Fri Jul 18, 2008 9:47 am
- Forum: General Discussion
- Topic: help on DC-AC inverter for Public art Project. Thks
- Replies: 168
- Views: 95064
Hello Federico, Using the MAX335, the absolute maximum theoretical time needed to write to every pixel in the display is around 2.5mS. This doesn't take into account the delay for signals to travel the considerable distance of the display (about 25x25feet if it is square). At a guess it would be pos...
- Fri Jul 18, 2008 3:53 am
- Forum: General Discussion
- Topic: help on DC-AC inverter for Public art Project. Thks
- Replies: 168
- Views: 95064
- Thu Jul 17, 2008 11:35 am
- Forum: General Discussion
- Topic: help on DC-AC inverter for Public art Project. Thks
- Replies: 168
- Views: 95064
Hello Federico Yes, your supply voltage must always exceed or equal the voltage being switched. So you would need a +15 and -15 supply and +5V for the logic section. Your AC supply should be arranges so that the common input pin swings both positive and negative with respect to the pixel display com...
- Thu Jul 17, 2008 10:49 am
- Forum: General Discussion
- Topic: help on DC-AC inverter for Public art Project. Thks
- Replies: 168
- Views: 95064
Hello Federico, I went on the web site. Very glossy, zero technical information! So I'm going to have to guess that it would be driven in the same way as a standard LCD. The MAX335 can only handle a maximum of +/-15V, so you would probably want to go for the type that operates on 10V AC. I will need...
- Thu Jul 17, 2008 10:15 am
- Forum: General Discussion
- Topic: help on DC-AC inverter for Public art Project. Thks
- Replies: 168
- Views: 95064
Hello Federico The switch section of the IC is effectively isolated from the logic side, so the two don't interact. You would connect all the COM pins of all the MAX335 chips to the AC signal, and connect each NO line to individual pixels. I haven’t studied the properties of the display all that w...
- Thu Jul 17, 2008 9:09 am
- Forum: General Discussion
- Topic: help on DC-AC inverter for Public art Project. Thks
- Replies: 168
- Views: 95064
Hello Federico, I'm a little confused as to why you should want to convert DC to AC. As far as I can see, you intend to take the DC output of each MAX335 switch (this chip is in effect just 8 serially controlled on-off switches) and convert to AC. This would mean that you would need a converter for ...
- Fri Jul 11, 2008 3:52 am
- Forum: General Discussion
- Topic: brighten 12v light (LED?) over 2 minutes; low voltage trigge
- Replies: 15
- Views: 14088
Hello Bryan, Let me know how it turns out. I’m still available if you need anything designing/building. On the subject of the LED illumination, I think you would still be looking at 30-40W power consumption. If a 110W lamp lasts 10 days, then the system will run for about a month maximum on the sa...
- Thu Jul 10, 2008 8:36 am
- Forum: General Discussion
- Topic: brighten 12v light (LED?) over 2 minutes; low voltage trigge
- Replies: 15
- Views: 14088
- Thu Jul 10, 2008 3:58 am
- Forum: General Discussion
- Topic: brighten 12v light (LED?) over 2 minutes; low voltage trigge
- Replies: 15
- Views: 14088
Hello Bryan, It would not be difficult to daisy-chain a load of linear drivers together, with the first one as the master. Actually this would make quite a good lighting effect, which could be usable in other applications. I suspect that the light needs to come on very slowly , and then speed up tow...
- Wed Jul 09, 2008 9:42 am
- Forum: General Discussion
- Topic: brighten 12v light (LED?) over 2 minutes; low voltage trigge
- Replies: 15
- Views: 14088
Hello Lyndon/Bryan, Yes, the linear/analog approach is the simplest, as you correctly point out, vision (at least human) is not linear. I suspect that you would need to have small steps at the beginning, gradually increasing towards the end, for a human to perceive this as a linear increase in brigh...
- Tue Jul 08, 2008 9:08 am
- Forum: General Discussion
- Topic: brighten 12v light (LED?) over 2 minutes; low voltage trigge
- Replies: 15
- Views: 14088
Hello Bryan, Had a look at the control board specs, and although it doesn't explicitly say so, it implies that there is a 'volts free' switch connected to J14. The annoying thing is it doesn't specifically say so, and I cannot see anything resembling a relay on that board. I thought the white rectan...
- Mon Jul 07, 2008 10:20 am
- Forum: General Discussion
- Topic: brighten 12v light (LED?) over 2 minutes; low voltage trigge
- Replies: 15
- Views: 14088
Hello Bryan, I should be able to design/build this for you, FOC. As I understand it, your 'PIC' board supplies a switched 12VDC supply, when the sensor is activated? Is this correct. Then you want a circuit operating on this switched supply to gradually bring on a 12V light. Please give specificatio...