2 or more transistor Research and Presentation Help

Discussion in 'Homework Help' started by thirdy, Feb 24, 2008.

  1. thirdy

    Thread Starter New Member

    Feb 24, 2008
    Hi, I am a 2nd year BS IT student, a newbie in electronics. We have a project in Basic Electronics(a group of two) and we are suppose to research for a device that has 2 or more transistors and demonstrate it(actuall or SPICE).

    What would be a good simple(maybe also interesting) device to present? Any schematics for it for NI Multisim 10? Any good sites to research info about it?

    We need all the help we can get. Thanks!
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    I get more than a third of a million hits on Google using the search terms "two" and "transistor."

    "Interesting" depends on whether one finds thing like "Atomic Frequency Standard" or "40 milliWatt Transmitter" or "Police Siren" to be sexy.
  3. SgtWookie


    Jul 17, 2007
    You might consider a 7400 or 7401 TTL IC. There are several transistors in one chip.

    They are both quad 2-input NAND IC's. The 7401 has "open collector" outputs, which require either pull-up resistors, or an output load that is connected to Vcc.

    The NAND gate is one of the most useful gates, since you can build any other basic gate using various combinations of NAND gates. You can use a 7400 or 7401 to light up standard red LEDs to show the state of the output. Use a 220 Ohm resistor in series with the LED so that you don't overload the IC or the LED.

    TTL requires a precise operating voltage range, however - your supply voltage should be in the range of +4.75 to +5.25.

    If you don't have a regulated power supply available, you could instead use a CMOS 4093 quad 2-input NAND gate. It will operate using a much wider voltage supply; approximately +3V to +15V, and a 9V transistor battery will power one just fine. They do not supply much output power, though.
  4. studiot

    AAC Fanatic!

    Nov 9, 2007
    Another device to look at might be the '555' timer IC. With this you can demonstrate both analogue and digital electronics in a vast array of configurations. There are always 555 threads on allaboutcircuits or google for some.

    This ic might be easier to obtain if you want a real one - there are lots of versions with letters at the beginning and end but they are all basically 555s.
  5. thirdy

    Thread Starter New Member

    Feb 24, 2008
    Thanks everyone! Right now I'm looking at 555 timer IC, and I think somehow I can get the basic idea, thanks to todays lesson in our electronics class where we brainstormed on determining the output of a circuit with lots of NMOS and PMOS