Shop OBEX P1 Docs P2 Docs Learn Events
Basic stamp cristmas lights — Parallax Forums

Basic stamp cristmas lights

polypoly Posts: 5
edited 2014-12-01 15:36 in BASIC Stamp
Hi everybody I'am working in this project using the basic stamp homework board for my christmas lights...but I am not sure how to connect my relay board to my basic stamp.....I already did all the programing...
I have my 4-relay board 5vdc coil....and my basic stamp homework board...I was able to run a program using LED'S on my board but I want to move on and add my relay board so I can connect my extension lights on it....ANY HELP WILL BE APRECIATED...thank..

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2014-12-01 14:51
    You're going to need some kind of relay driver unless your relay board already has that built-in. Nuts and Volts Column #6 (http://www.parallax.com/downloads/nuts-and-volts-basic-stamps-volume-1) has some suggestions for this. A ULN2803A (http://www.parallax.com/product/500-00005) works well for this and has built-in snubber diodes to protect the Stamp I/O pins from back-EMF when the relays turn off. With the Homework Board, you especially need a driver because there are built-in 220 Ohm resistors in series with the I/O pins to limit the maximum amount of current the I/O pins can provide (to prevent damage to the Stamp).
  • polypoly Posts: 5
    edited 2014-12-01 15:05
    Hi mike thanks for the answer I alreday have a Opto-Isolated 4 Channel Relay Board...I just want to know if anybody tried this configuration before....Kind of new in this...
  • Mike GreenMike Green Posts: 23,101
    edited 2014-12-01 15:36
    The optoisolators are LEDs on the input side. Just remember the Homework Board's built-in series resistors. Look at the datasheet for the optoisolator to see how much voltage & current is needed to turn it on and whether there's a built-in series resistor or other current limiter.
Sign In or Register to comment.