Procedure and Tasks

The task of this series of experiment is to build simple but useful circuits.

Start:

· Use your bread board and follow the instructions of the manuscript

· connect the OpAmp μA741, the two voltage sources for V₊ and V_-.

· define input, output and ground

Voltage divider:

· Build a voltage divider with the resistors R₁ and R₂ and a 10V battery on the bread board

Inverting amplifier:

· Build a voltage divider with a 10V battery and resistors 100kW and 100W on the same board.

· Use R₁=100W, calculate R₂ for an amplification of 10 and 100 (since resistor are only available with 2 digit values choose the closest value).

· Amplify the voltage of voltage divider of about 10mV with an output resistance of 100W with the two amplifications.

· What is the output voltage? Take notes for the report.

Non-inverting amplifier:

· Use the same voltage divider

· Use R₁=10W, calculate R₂ for an amplification of 10 and 100.

· Amplify the same voltage of about 10mV with an output resistance of 100W with the two amplifications.

· What is the output voltage? Take notes for the report.

Ac amplifier:

· Use resistors of 1.8kW and 18kW (100kW) and a capacitor of 0.1μF for the ac-amplifier (amplification of about 10).

· The voltage source is a sinus wave generator with an ac-output of about 1V.

· Build a voltage divider with resistors 10kW and 1MW on the same board for the ac-output (reduction by a factor 100).

· Amplify the voltage of 10mV.

· Register on channel 1 of an oscilloscope the input voltage of 10mV and on channel 2 the output voltage.

· Determine the amplification and the phase relation as a function of frequency at 10, 10², 10³, (1,2,4,7,10)x10⁴ Hz

· Repeat the same experiment for an amplification of 100 using 180kW in the ac-amplifier.

· Take notes for the report.

Follower:

· Build a follower.

· With an additional battery of 9V and resistors of 100kW and 1MW build a voltage source of 1V with an output resistance of 100kW. follower.

· Put a load of 100 directly on the output and measure the voltage.

· Use the follower to reduce the output resistance of your voltage source.

Current source:

· Build a current source.

· Use a voltage divider (10V, 10kW, 1MW) for the input voltage and potentiometer of 1kW for the load.

· Measure the current as a function of load resistance.

· Use a voltage divider (10V, 18kW, 1MW) and measure the current as a function of load resistance.

Differentiator:

· Use R=100kW and C=.1mF.

· The voltage V_in is supplied by the sinus wave generator.

· Use a voltage divider with 1kW and 100W.

· With the oscilloscope the input voltage V_in is measured on channel 1 and the differentiated voltage V_out on channel 2.

· Use the frequencies 10, 10², 10³, 10⁴, 10⁵ Hz.

· Plot the ratio of V_out /V_in versus the frequency

Rectangular oscillator:

· Use R=10kW and C=.1mF.

· Measure the amplitude and frequency of the output voltage V_out on the oscilloscope.

· Instead of R=10kW use the values 100kW, 1kW.

· Make a table of frequency versus resistance R.

· Calculate the expected frequencies.

Harmonic oscillator:

· Instead of 750W use 405W (1kW and 680W in parallel)

· Use R=1kW and C=.01mF.

· Measure frequency and amplitude.

· Measure the resistance of the lamp (during operation).

· Replace R by 10kW, 100W and repeat the measurement.

· Make table

Integrator:

· Instead of the OpAmp mA741 use LF356.

· Use R=10kW and C=2.2mF.

· Build a voltage divider with a 1kW potentiometer, 1MW and a 10V battery.

· Apply the resulting voltage to the input of the circuit and watch the output voltage with the multimeter as a function of time.

· Adjust the potentiometer so that the maximum output of about 8-10V is reaches after one minute.

· Measure the resistance of the potentiometer.

· Measure and plot V_out as a function of time.

· Register the V_out on the oscillator.

Measurement of the magnetic field of a permanent magnet.

· Make a pickup coil with 20 turns and a known area.

· Place the pickup coil between the poles of the magnet and shorten the capacitor briefly.

· Pull the coil out of the magnet and measure the integrated voltage.

· Calculate the magnetic field.

Schedule

First day:

· Inverting amplifier with voltage divider

· Non-inverting amplifier with voltage divider

Second day:

· Follower with 1V voltage source (voltage divider)

· Inverting amplifier with follower between voltage divider and amplifier

Third day:

· Ac amplifier

· Current source

Fourth day:

· Measurement of the impedance of an inductor with sinus generator and oscilloscope

Fifth day:

· Differentiator

· Integrator

Sixth day:

· Rectangular oscillator

Seventh day:

· Harmonic oscillator

Eighth day:

· Operational amplifier test