Voltage Readings without buildng circuits?

Discussion in 'General Electronics Chat' started by paul_alan, Nov 27, 2011.

  1. paul_alan

    Thread Starter Member

    Nov 5, 2011
    If I adjusted the Function Generator for a Sine Wave output of 15V p-p at a frequency of 2kHz and adjusted the DC offset to -5V DC, how can I determine what the most postive Voltage measurement on the Oscilloscope woud be without physically constructing the circuit? I'm trying to get some formulas or short-cuts to help me as we get more in depth with AC/DC theory
  2. Adjuster

    Well-Known Member

    Dec 26, 2010
    If the function generator was correctly calibrated you would expect to get the voltages as stated, so the maximum voltage would be 15V/2 - 5V or 2.5V.

    A possible complication arises if the generator is designed to give the correct amplitude only when terminated into a particular impedance, such as 50ohms. In this case, the amplitude will be incorrect into different impedances. For reasonably low frequencies at least, approximately double amplitude will be obtained when a defined low impedance generator is used to feed a high impedance load. This requires attention, as neglecting it may allow excessive voltages to be applied to the circuit under test.