help how hookup a relay

vw_gti

hi im kinda new and i need to hook up a relay to my education bored what pins do u use and is the any thing special to put in the programs

thanks
for your help

Mike Green

Download Nuts and Volts Column #6 from Parallax. At the end of the column, there's a diagram that shows how a relay should be hooked up.

In your program, a HIGH <pin> would turn the relay on and a LOW <pin> or INPUT <pin> would turn the relay off. Look at the chapters in the Stamp Basic Syntax and Reference Manual for a description of those statements.

Nuts & Volts Index: www.parallax.com/Resources/NutsVoltsColumns/tabid/272/Default.aspx

If you are using a HomeWork Board, there's already a 220 Ohm resistor in series with the I/O pins. You'll need to subtract that from the resistance shown in the Nuts and Volts Column. If you have it, use a 150 or 180 Ohm resistor in series with the built-in 220 Ohm resistor. With the Board of Education, use the 390 Ohm resistor that's recommended in the column.

Post Edited (Mike Green) : 6/14/2009 6:12:40 PM GMT

phil kenny

Basic Stamps can only provide a limited amount of current at
the output pins. I'd suggest using a transistor to drive the relay.

If you use a 220 ohm or larger resistor between the Stamp output
pin and the base of your transistor, the Stamp will be able to
operate the relay.

Find a small relay that can operate on +5 volts.

Programming the Stamp is then jusy a matter of making
that output pin high or low.

phil

Prettybird

·a LM 311 is also an excellant choice to drive a relay using a TTL input and up to 15vdc 100 ma output. Don't forget the clamping diode no matter what you use.

vw_gti

its been toolong since hooked up a transistor could u give me some help on this
thanks

Mike Green

Either you didn't read the article I suggested or there's something in the article you didn't understand. Can you describe that?