PC fans and LCDs!

Discussion in 'The Projects Forum' started by Arud, Sep 28, 2008.

  1. Arud

    Thread Starter New Member

    Sep 28, 2008
    3
    0
    Hello Firstly i would just like to say hello to everyone and that Thanks in advance for any help given, it will be greatly appreciated.

    I am completely new to Circuitry building but have a project that I am trying to do.

    Essentially i want to be able to plug a wall wart of some kind into this "box" and from there be able to power 4/10 PC fans, A Temp/humidity sensor and an LCD screen with controls.

    I have no idea what components I would need other than the obvious ones.
    I have attached an image I drew of what I am trying to make.

    I know programming will be needed, but that can be tackled after the circuit is made..

    What do you recommend as parts and how could I make this work?

    Thank you again.




     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    If everything is going to be powered by 12 VDC, then a wall wart with a higher voltage rating is a good idea. Use a rectifier diode and capacitor to filter the input voltage. Then a regulator like a 7812 to provide a more accurate 12 volts. Add up the current needs of all the devices to get an idea of the size of the wall wart. You may also have to place the regulator on a heat sink.

    It's not clear in your diagram, but don't pass the fan current through the indicator LED's.

    There is no information on the sensor or the display, so we can't really advise on those.
     
  3. Arud

    Thread Starter New Member

    Sep 28, 2008
    3
    0
    Well i haven't chosen a Sensor, i was wondering what you guys though.
    As for a display i want to use a 2x16 LCD screen, also wonder what you guys would recomend.

    The LEDs are to show that the power is ON to the fans, and when the powers off, they are off.

    i was also thinking about potentiometers for the fans, so they can be made to run a little slower or a little faster..

    I really have no idea how to get even started on this project so any help is appreciated. :)
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    How are you planning to get data to the LCD display? That usually takes a microcontroller. Indicator LED's are lots cheaper & easier. If you find a temp & humidity sensor with voltage outputs, then a panel meter might do well to display the values. A conditioning circuit to make the voltages read directly as temp & humidity, plus another couple of LED's to show which reading is being displayed makes life simpler.

    My oldest uses a cluster of 120 VAC muffin fans to cool his equipment in the theater room. He is able to use a simple (and cheap) lighting dimmer to vary fan speed.

    Someone may be able to simplify this idea...
     
  5. Arud

    Thread Starter New Member

    Sep 28, 2008
    3
    0
    I don't know how i'm going to get data to the LCD screen, i'm a complete newbie to it all.

    The screen won't just be used to show temps/humidity info, there are other things i wish to display, it should have navigation buttons to the side to get to the other info..

    I have looked for sensors and found this one..

    http://www.sensirion.com/en/01_humidity_sensors/03_humidity_sensor_sht15.htm

    Would that be sufficient for my needs?

    Also, does "Calibrated & digital output (2-wire interface)" mean that i can have two wires running from this to outside the box it is in?

    As that is what i would need, i am not looking to get temps/humidity info for the Circuit board, but outside the box it is going to be housed in.

    It seems like a lot to ask for but it's exactly what I need..

    Would it be possible to have the LEDs to show that the fan sockets are on/off?

    I know these are a lot of questions but I signed up here in hope of getting much needed help.

    Thanks again.
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Well, life will be busy if you wish to pursue the LCD display and digital sensor. You will have to have a microcontroller receiving the data and driving the display. The 2 wire interface is a communications protocol.

    You can find uC's with that interface built in, and the ability to directly connect to LCD displays (can't say for sure about yours). But you will have to also obtain a programmer for the uC and write the code to operate it.

    The up side of this is that adding those additional functions will be simpler than going an analog route. It is possible to display the temp and humidity on a LCD or LED panel meter. It would require sensors with pure analog outputs.

    The easy part is in the LED indicators for the active fans.
     
Loading...