I would consider anything that uses a semi-condutor material to be active, Silicon and Germanium transistors included.
On 10/24/07, Jeff DePolo <[EMAIL PROTECTED]> wrote: > > Beta is the current gain of a transistor, HFE and Hfe. > > Finally something we can agree on. But the way you used "beta" was > referring to the net gain of a *circuit* using a transistor in > emitter-follower > configuration, which I don't think is the correct use for the term, and > which is why I put "beta" in quotes in my reply. > > > An emitter follower will have power gain only if the > > transistor has a beta, HFE or Hfe, greater than 1, but is > > active in any case. > > A transistor is capable of gain, thereby making it an active device. It's > gain (or lack thereof) in a maldesigned circuit doesn't change the fact that > the device, itself, is still capable of power gain. > > A dead transistor with an hFE of < 1, in my opinion, makes it no longer a > transistor. If we're going to consider broken or burned-out components in > our discussions, we're never going to get anywhere... > > > Yes diodes and transistor have junction capacitance, > > resistance, but get their properties from entirely different > > means than passive devices such as a resistor. Junction > > capacitance is a function of energy supplied to the device. A > > capacitor does not change its properties based on energy > > supplied, unless one exceeds its specs. A diode does. > > A transistor and diode change their properties based on the > > energy supplied. This makes both active. > > Under your definition, if there is a change in one of its properties of a > device when energy is supplied to it, the device is active, do I understand > that right? A diode's capacitance changes with applied voltage, OK, I > concur. The voltage across a resistor changes with current through it. An > inductor's reactance changes with frequency. The resistance in a length of > copper wire changes with temperature. So I guess all of these are active > devices? > > > > > > > > > > > Yahoo! Groups Links > > > >
