Shop OBEX P1 Docs P2 Docs Learn Events
new to this...need help or advice — Parallax Forums

new to this...need help or advice

taylorbmxtaylorbmx Posts: 2
edited 2008-01-06 22:35 in BASIC Stamp
Hi..I have just purchased..."what's a microcontroller with home workboard" kit.· I am trying to learn this stuff and figured this would be a good start. I have a project that I am needing to control a pnuematic cylinder (120V mac valve)·and 25w 120v party light, a red and a green. I am in the process of building a bmx starting gate, that the gate will drop automatically after a short recording of the bmx cadence is played and after the green light comes on.

My question is..

··· I have been told that I need a relay to be able to use the micro controller with a high voltage, so I dont blow the whole thing up. How does this work and what type of relay DO I need to use with the Parallax Basic Stamp Kit? Especially since I am mixing high and low voltage together...

Any help is greatly appreciated.

thanks

Comments

  • David H.David H. Posts: 78
    edited 2007-12-31 16:49
    Taylorbmx,
    I'm sure more knowledgable people will reply to you also, but the BasicStamp will output a voltage of 5V. So you will need a relay with a 5v input coil, and can handle the output voltage you are using. You should also have a diode across the contact pins of the input coil to prevent inductor kick that might damage the BasicStamp. There are many solid state type relays that would work. You can search some places like www.digikey.com for the relays. Hope this helps you get started.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    David


    There are 10 types of people in this world,...
    Those that understand binary numbers, and those that don't!!!
  • UnsoundcodeUnsoundcode Posts: 1,532
    edited 2007-12-31 16:59
    Parallax used to sell the Crydom D2W203F solid state relay but I think they may have discontinued them. This is Crydoms link to pcb mounting SSR's

    http://www.crydom.com/products/productFamilyList.aspx?idProductLine=2

    Pay special attention to the signal/control voltage and current and the output voltage and current.

    Jeff T
  • kelvin jameskelvin james Posts: 531
    edited 2007-12-31 18:57
    You are basically looking at building a 120v ac relay controller board. Since you are new to this, and working with live ac can be potentially hazardous to your well being, there are many pre-built boards already being offered. Parallax ( efx-tek product ) has the RC-4 relay board which takes serial input control from a stamp. You also need to purchase the solid state relays and solder them to the board. It may seem a little expensive at first, but the cost will be justified by simplifying the hardware components for your project. As mentioned before, the operating amperage needs to be within the relay specs. Have the relay board mounted in a box first before putting power to it, as you tend to forget that there is live ac on the back of the board.

    Post Edited (kelvin james) : 12/31/2007 7:46:51 PM GMT
  • taylorbmxtaylorbmx Posts: 2
    edited 2008-01-06 03:28
    thanks for all the input..I think I have found what I was looking for...I will do some more research and a little trial and error. Any advice on how to write the DEBUG program to how to help me know what to do....I think I have a good idea....but again, I am not a pro and still have alot reading to do...BUT...I basically need my BS-1 to tell an AP-8 cadence recording to play a 7 second recording. In·6 seconds I need my·board to throw a 120v red light on, and·at 7 seconds and when the recording is finished, a green light comes·on and will send a message to have my pnuematic·cylinder drop my gate initiating the start of the race (using the RC-4)....If anyone has ever raced BMX, they know what I talking about.....··I am reading the chapter now on the LED section that talks about having the light coming off and on...SO..Any input is greatly appreciated....
  • kelvin jameskelvin james Posts: 531
    edited 2008-01-06 22:35
    Just go to www.efx-tek.com and look at the documentation and forum there. I am sure JohnnyMac will give you all the help you need to get you started. Let us know how you make out.
Sign In or Register to comment.