# Oscilloscopes

Oscilloscopes

The two controls on an oscilloscope we are interested in are;

• Y-gain in volts/division, 1 v/div.
• Time base in time/division, e.g. 0.002 s/div.

Input connected to ground (zero volts) and timebase switched off, oscilloscope trace is a spot in the middle of the screen.

3 volts from a dc battery (Y gain set to 1V/div, timebase off), the oscilloscope trace is a spot which moves 3 squares (divisions) up.

Input connected to ground (zero volts) and timebase switched on, trace appears as a horizontal line in the middle of the screen.

3 volts from a dc battery (Y gain set to 1V/div, timebase on), trace appears as a horizontal line 3 squares above the middle.

3 volts from an ac power supply (Y gain set to 1V/div, timebase off), trace appears as a vertical line 6 squares long.

3 volts from an ac power supply (Y gain set to 1V/div, timebase on 0.002 s/div), sine like trace appears.

The peak voltage (amplitude) is 3V.

The time period (T) is 8 squares x 0.002 = 0.016 s.

We can calculate the frequency (f) in hertz (Hz) using the equation below;

f = 1 divided by 0.016 = 62.5 Hz