Public projects 3

A Chronicle of Fails

by tolgadurudogan

  • 1 comment
  • 6 respects

Using Arduino Mega Sensor Shield with Arduino DUE

Project showcase by tolgadurudogan

  • 1 comment
  • 4 respects

Tricks for Controlling DC Motors

Project tutorial by tolgadurudogan

  • 94 respects

Toolbox 3

Thrust Vector Controlled Rocket

Project in progress by Cole Purtzer

  • 29 respects

Inverted Pendulum on a Cart

Project showcase by zjor

  • 40 respects

Comments 3

  • Switching Using Transistor over 2 years ago

    Approach is correct but may lead burning the components if implemented without control.
    Transistors have forward gain coefficients (hfe) and passes amplified base current (Ib) by this value at collector (Ic).
    Ic = hfe * Ib
    And base current is typically Ib = (Vb - VBE) / Rb
    (VBE = 0.3 V for Ge-, and 0.7 V for Si-transistors - typically)
    So on this example;
    Vb(Ard.Pin.2) = 5V, Rb = 1k and if VBE = 0.7V -> Ib = 4.3 mA
    and if hfe = 50 as a typical value Ic becomes 215 mA, which may bur a LED.
    Refer to transistor datasheets for the parameters.

  • Tricks for Controlling DC Motors over 3 years ago

    At first, thanks for your comments.
    " the bridge circuit the bottom 2 transistor should be NPN not PNP as the current is in reverse..."
    It's not a must actually... Perhaps you considered another path for reversing current. My considerations was either T1A-Motor-T1B or T2A-Motor-T2B paths.
    "...putting 4 diodes between collector and emitters will protect the transistors from spikes back EMF from the motor induction..."
    I think if transistors are selected at suitable ratings, effect of spikes would be negligible during normal operation. Anyway such spikes by induced coils of DC Motors, appear mainly when motor is stopped. But it's a transient case and takes very short while that can be handled by transistors.

  • Tricks for Controlling DC Motors almost 4 years ago

    Thanks for interesting, and hopefully all of them will fit well on your implementations.

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