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viking
11-16-2006, 11:11 AM
· Would it work to use the power from the transformer powering a BS1 or 2 for the supply power say for a solid state relay using a uln2003 if the power was tapped before it went to the stamp and use the VSS on the stamp for the ground of the uln2003?

Chris Savage
11-16-2006, 11:33 PM
Viking,
·
·· Not sure I understand what you’re trying to do.· Perhaps if you could illustrate it we might be able to offer some sound advice on your plans.· Take care.

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Chris Savage
Parallax Tech Support

viking
11-21-2006, 11:10 AM
ME do a diagram? Surely you jest !!!http://forums.parallax.com/images/smilies/lol.gif

·Well anyway I intend to power a BS2with a 9V or 12V wall transformer connecting to the PWR terminal and the GND. The ULN2003 takes a ground connection at pin 8 I thought Icould get this at the stamp GND terminal. I will be switching solid state relays (led's) The ULN switches the GND circuit so I need a power supply to the + plus at the solid state relays. These operate from 5V to 32V. I thought I could tie into the transformer feeding the stamp before it enters the stamp for this power as long as the transformer has enough Ma to supply all of it.

kb2hap
11-21-2006, 09:30 PM
Sure you could tie the uln2003 to the stamp ground but the stamp ground also needs a ground!

the + or com lead on the uln2003 will get connected to whatever voltage you will be powering (SSR). so if the SSR needs 12V then then uln2003 will need 12v on the + or com lead. this can be taken from the power before the stamp as long as the supply can handle it.

http://www.parallax.com/dl/docs/cols/nv/vol1/col/nv6.pdf

this link has a pdf with a little info on what your trying to do.

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DTQ

Randy Evans
11-21-2006, 11:41 PM
Viking:

If I'm reading you right, you want to power the SSR With the unregulated input supply voltage (before it goes through the 5V regulator. That fine, you're on the right track. Pin 8 of the ULN2003 goes to GND and pin 9 goes to Vin (unregulated).

Randy

Chris Savage
11-22-2006, 02:19 AM
Viking,
·
·· If I am reading this right, you could tie the 5V supply to any SSR input + pin and then the – input pin would go to the output of the ULN chip.· When you make the appropriate ULN input HIGH that SSR would be activated.· Since you are controlling a non-inductive load you don’t need the COM/V+ line connected, but you do need a common ground between the ULN and the BASIC Stamp.· I hope this helps.· Take care.

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Chris Savage
Parallax Tech Support