start gate help

Solenoid start gates make for consistent heat starts.
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gpraceman
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Re: start gate help

Post by gpraceman »

mrvoltz wrote:First of all, the serial port is only 5 V also.
What is your source for that?
gpraceman wrote: Until then, there are also adapters on the market, like this one, that can be used with computers that do not have a parallel or serial port.

http://www.keyspan.com/products/usb/mpr/
Well, I have to back track a bit on this recommendation. I recommended this device before personally trying it myself. :oops: I went and recently bought one and installed it on my new laptop along with the associated software. The serial port works just fine and it shows up on the list of COM and LPT Ports in the Windows Device Manager as I would expect.

I assumed the parallel port setup would be done in the same manner. I was rather suprised that the parallel port did not show up on the list of COM and LPT Ports, but instead show up under the list of Universial Serial Bus Controllers as "USB Printing Support". I would have to do some research on how it would be possible to communicate with such a parallel port.
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mrvoltz
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Re: start gate help

Post by mrvoltz »

In the past with the right driver chips some computers provided 12 V at very low currents but this quote from this site:

http://www.tkk.fi/Misc/Electronics/circ ... power.html
In the last few months there have been increasing notification of problems on lap-tops and a few desktop computers because the serial port signals are only driven to +-5V (rather than 12V nominal current limited on PC's etc.). So if you go for such a design make sure it will work on +3 and -3V - all you may have left. Longer term USB may be taking over - something to think about if you are going into production.

Copyright Tomi Engdahl 1997-2000
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