Common Problems

Useful Info for Lab 1

  • This document describes how to make delay measurements using the Tektronix scopes.
  • This document describes how to make Bode plots in Matlab.
  • This document describes how to make FFT measurements using the Tektronix scopes.

Vertical rails

Remember that the vertical rails on your breadboard may not be connected across the break in the middle. You have to make jumpers. Jumper them all right now, it will save you time and frustration later.

Benchtop Power Supplies

The benchtop supplies in the lab have three outputs:

  • +5V adjustable
  • +20V adjustable
  • -20V adjustable

All of these voltages are provided with respect to the COMMON (which is black). The GROUND (green) connector is connected to earth ground and has nothing to do with the power supply output.

The bottom line is that the COMMON (black) must be hooked up to the ground line in your circuits. Your circuit will not work without this connection.

Bypass capacitors

Each integrated circuit (IC) in your system should have bypass capacitors. These capacitors should be placed like so:

  • Between the positive power supply and ground
  • Between the negative power supply and ground

These capacitors filter high frequency currents that flow through your power supply wires. Without bypass capacitors, these high frequency currents can flow into your op-amps where they can be amplified and appear at the output.