Relay part number?

Speaker

Can anyone give me a part number and a supplier for a good relay that will trigger easily at stamp output voltage levels?· I am currently trying to use a 9v relay by routing pin output to a base of a transistor.· Is there a relay that will work straight off the pin?

dandreae

The BASIC Stamps require protection when controling relays.· We·recommend the ULN2803 Line Driver chip for this circuit.· It cost a $1.50 and can control up to 8 relays.· Parallax's part number is 500-00005.· If you click on the product page you'll find a Nuts & Volts article number 6 that will show how to connect it up with sample code.

Dave



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Dave Andreae

Parallax Tech Support·

Chris Savage

Speaker,

The problem is that Relays are inductive devices and you wouldn't generally want to run them off your I/O pin directly. Besides being inductive they also generally draw more current than you want to have on an I/O pin. Using a transistor (or the ULN) is an inexpensive way to protect your BASIC Stamp Module.

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Chris Savage
Parallax Engineering

Joms

I know that you are not supposed to connect a relay directly to the stamp.· But I do use the following relay sometimes when I only need to energize a few at a time.· They are not too spendy and they have the diode built into the relay so you do not need really any external parts.

The·most I have ever used is 12 on a stamp (12 different stamp output pins) but only 3 were ever energized at a time.

Have a look at the following digikey number:

255-1403-5-ND

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=255-1403-5-ND

Speaker

Got it now. Thanks all.

Alan Bradford

A transistor or ULN IC Chip is cheap Insurance for a $40 Stamp Chip

Alan Braford
Plasma Technologies
www.plasmatechnologies.com