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how to control a high voltage stuff with microcontroller — Parallax Forums

how to control a high voltage stuff with microcontroller

m_ghv_geom_ghv_geo Posts: 6
edited 2010-04-01 06:53 in BASIC Stamp
hi all i goat my first microcontroller yesterday as a learning kit at radio shack it is called parallax basic stamp bc-2 item # 90005
i was playing, discovering and learning with it a few days but know am and up with tons of questions

first question is how can i control lets say a 120v lamp with it eyes.gif ?

next question is this thing only has 9 volt Battery sou its max output is 9 volts lets say i want to control a few 12 volt motors with it how can i do that?

i can figure out by my own how to program but i need help to how to connect higher voltage stuff to microcontroller?

blush.gif please go easy on me i am new in this microcontroller world

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-03-31 05:19
    1) An ordinary 9V battery cannot put out enough current for a motor more than for a few minutes. It simply doesn't have the capacity. You need an adequate power supply.

    2) Nuts and Volts Column #6 discusses how to control higher voltages and higher currents using a Stamp I/O pin. Download it from Parallax and read it.

    3) Controlling any kind of AC device is potentially very dangerous. You need to know what you're doing. For 120VAC devices up to a few Amps, you can use an appropriate relay or SSR (Solid State Relay). Parallax makes an Industrial Control Board that provides for several such relays. EFX-TEK also has a Solid State Relay board. Using either one is still potentially very dangerous. You can get killed.
  • m_ghv_geom_ghv_geo Posts: 6
    edited 2010-03-31 06:46
    thanks for second answer i will try to find it
    it would been good if you wrote a direct link to that page thx any way
  • m_ghv_geom_ghv_geo Posts: 6
    edited 2010-03-31 07:02
    i found Nuts and Volts volume #6 but i have trouble finding "how to control higher voltages and higher currents using a Stamp I/O pin"http://www.parallax.com/Resources/NutsVoltsColumns/NutsVoltsVolume6/tabid/449/Default.aspx

    Mike Green said...
    1) An ordinary 9V battery cannot put out enough current for a motor more than for a few minutes. It simply doesn't have the capacity. You need an adequate power supply.

    2) Nuts and Volts Column #6 discusses how to control higher voltages and higher currents using a Stamp I/O pin. Download it from Parallax and read it.

    3) Controlling any kind of AC device is potentially very dangerous. You need to know what you're doing. For 120VAC devices up to a few Amps, you can use an appropriate relay or SSR (Solid State Relay). Parallax makes an Industrial Control Board that provides for several such relays. EFX-TEK also has a Solid State Relay board. Using either one is still potentially very dangerous. You can get killed.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2010-03-31 13:06
    See Figure 6.3 in the article.· The appropriate relay (solid state or mechanical) can control high voltages.

    The Basic Stamp and transistor drive the relay. The diode is critical to protect them when the relay coil power is disconnected.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-03-31 14:25
    Parallax carries a Digital I/O Board Kit that controls up to 8 relays, either mechanical or solid-state. This kit requires soldering. If your soldering skills are fairly decent then this is the ideal way to control 120VAC devices and can be done serially or parallel using a simple command such as HIGH 0. Take care.

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    Chris Savage

    Parallax Engineering
    ·
  • revrev Posts: 27
    edited 2010-03-31 16:30
    This is a nice and realatively cheap solid state relay that can handle a few amps @110V, and doesnt require a diode or transistor on the low voltage end, all you have to do is get the polarity right.
    A very quick and easy way to start controlling high voltage right away with your basic stamp.
    http://www.grainger.com/Grainger/items/6C900?Pid=search
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-03-31 19:16
    rev, the SSR we carry handles 8A @ 125V. Looks like we just got sold out of them, but they're as easy to control as an LED. They also fit nicely into the Digital I/O Board I mentioned.

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    Chris Savage

    Parallax Engineering
    ·
  • m_ghv_geom_ghv_geo Posts: 6
    edited 2010-03-31 19:56
    thanks all for those info's my soldering skills are rely bad i need some one to teach me how to use soldering maybe i will go to "nyc resistor" to learn properly but for know i have to learn a bought the transistors how they work and how to use them can one of you provide a link to the page which will help me understand their principals
  • rixterrixter Posts: 95
    edited 2010-03-31 22:09
    m_ghv_geo,

    You need to look at Column #6, not volume #6. Column #6 is in Volume #1: ...... http://www.parallax.com/Portals/0/Downloads/docs/cols/nv/vol1/col/nv6.pdf

    Rick
  • eod_punkeod_punk Posts: 146
    edited 2010-04-01 03:20
    M_ghv_geo I found these videos on eagle to be helpful, maybe his soldering tutorials cam help you as well.

    http://tangentsoft.net/elec/movies/

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    There is no problem that can't be solved with a suitable amount of explosives!

    EOD Memorial
  • m_ghv_geom_ghv_geo Posts: 6
    edited 2010-04-01 06:39
    thank you eod_punk
  • m_ghv_geom_ghv_geo Posts: 6
    edited 2010-04-01 06:53
    only think what am i looking for is how to use the transistor does someone knows really really simple project were transistor is used it will be good if transistor will be 2n3904 thank you all for your wonderful answers
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