Hi Researchers.
I'm looking for an electronic device, with lots of switches/plugs,
that can be controlled by a computer, the purpose of this is to design
my own marquee sign with flexible combinations, like light goes on
from the ends, and moves to the middle etc.
I'm a computer programmer, so if there is a device with an active-x
control to issue the on/off commands i can call control it from my
application, but if there is a ready software for that it's of course
better.
I'm looking to pay for that device between 50-100 dollars, but I?m
interested in the info even if it's more expensive.
BTW: I?m not looking for LED signs, I have my own wooden characters
surrounded with lights, and would just like to control the sequence of
the characters lighting.

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Request for Question Clarification by maniac-ga on 25 Aug 2004 17:58 PDT

Hello Magician,

Can you please clarify:
 - the number of lights you expect to control
 - the amount of current used by each light (or set of lights)
 - if a serial interface (or USB) is acceptable or if a PC compatible
card is needed
 - if you need isolation
 - if you expect to package this within an external unit (part of the lights)

To give you an example, see
  http://www.omega.com/pptst/PCI-PDIS0.html
which has a description of 8 / 16 channel high voltage / high current
isolated switch / relays. I realize this is far more expensive that
you indicated, but is representative of a device that is safe to use
in your computer system.

  --Maniac

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Clarification of Question by magician-ga on 26 Aug 2004 08:57 PDT

Thanks Maniac

I guess I'll have to do some more research in my part, because i
cannot ansewr those questions yet, then thing is, I don't really have
electronic engeneering experiance, I don't know what isolation is, and
i don't  know the voltage current of the lights, i guess i'll have to
study.
The lights are like little X-mas lights surrounding the characters by
drilled holes, and it's between 35-60 bulbs around one letter. and
it's 16 characters in total.

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Request for Question Clarification by maniac-ga on 26 Aug 2004 16:03 PDT

Hello Magician,

Hmm. A few hundred lamps to drive, that can be a pretty significant
problem to solve at low cost. If you can work with LED's (instead of
lamps), the current is relatively modest and the components can be
relatively inexpensive. Look at
  http://www.apogeekits.com/scrolling_marquee.htm
for a sample 10 character marquee display using LED's (includes the
CPU and control units to drive the display). Also note
  http://www.vorne.com/electronic-displays-gy2200.htm
for 2" high letters (again 10 of them) but also note the sharp increase in price.

Isolation, by the way refers to a method used to protect the computer
circuitry. There is a separation (e.g., by optical methods) between
the unit being controlled (in your case - lights) and the logic level
controls of the computer. You generally have to provide separate power
supplies as well. This prevents a spike of current or voltage from
damaging the computer.

  --Maniac

It may be outside your budget, but you can get computer interfaces for X10 devices.
http://www.smarthome.com/x10comp.html

There are also computer controlled switched for stage lighting
applications, such as
http://www.pulsarlight.com/Universal%20Interface.htm  (UK site)
  This is a controller that can work with computers RS232 and converts
those signals into 0-10V that is used with stage dimmer packs. You
could also use a MIDI port on your computer.

Theatrical/disco lighting places are probably the place to go if you
want a ready-made solution, but might be expensive, eg
http://www.prolightingsupplies.com/
might be able to help.

You can also get interface boards for computers with opto-isolators
for mains switching, such as www.maplin.co.uk and search for product
codes PF99H or VF54J:

RP99H  - DMX512 Controller & Protocol Convertor
   This unique module will allow you to run professional
lighting/disco equipment fitted with the 250kB DMX512 control
interface from your own PC (RS232 @ 9600 baud), a BASIC Stamp or
simply from analogue potentiometers. The board can also be configured
as a DMX receiver and take out either RS232 commands, 4 x 0-5 V
Analogue channels or even control four standard hobby servos! The
module is supplied complete with some simple Visual Basic software to
allow you to control your DMX equipment using the standard RS232
serial port on your PC. With this application, the user can control
devices that receive a range of values (like a dimmer) or a number of
discrete values (like a colour wheel). Full source code is included. A
programmer may like to add controls for altering a lamp?s position on
an X- or Y-axis, or specific devices for custom made special effects.
The application uses an MDI interface to allow the user to have as
many controls open at any time. A full datasheet is available from our
technical services department.

VF54J - K8000 Computer Interface Board
 This Computer Interface Board excels in its simplicity of use and
installation. The connection to the computer is optically isolated, so
that damage to the computer is not possible. The interface is
controlled using TURBO PASCALTM procedures. The interface itself has
16 optically isolated digital connections, which can be freely chosen
as either inputs or outputs (e.g. 6 inputs and 10 outputs) according
to how they are set up by the user. Up to four interface boards can be
connected together (one master and three slaves).
-  Simply connects to the printer port 	
-	Printer by-pass connector on board 	
- 	16 opto-isolated inputs or outputs
(I don't think this switches mains directly - would need relays or triacs)

Owain