Scope of the measurement:	Testing basic transistor circuits
(Measurement no 5)
	
Measurement done by:	<student’s name>
< student’s name >	
Measuring group:	<course>, <group number>	
Date:	<day>, <month>, <year>	
Course leader:	(online course)	
		
Applied instruments
Digital oscilloscope	AGILENT 54622A		
Function generator 	AGILENT 33220A		
Digital multimeter (6½ digit)
Power Supply	AGILENT 33401A
AGILENT E3630A		
Test panel	BME-VIK II/5		
Online course environment
Open the page http://www.hit.bme.hu/~bajor/V2M05/ and log in using your NEPTUN code. The system selects the appropriate test panel based on your code, then configures the supply voltage and the amplitude of excitation applied to the input. The waveform is a 1 kHz sinusoidal in all cases. On the webpage you can find various measurement configurations and results. You can interrupt your work at any time (i.e. you can close the page) because next time you log in with your code again, you will get the same dashboard with the same measurement results. However, the results will show minimal variance during re-downloads because new measurement snapshots are taken with each download, which may differ due to noise and measurement uncertainty, to a negligible extent. This difference has no effect on the final results if they are properly rounded from an engineering point of view and only meaningful decimal digits are used.
Use the results obtained from the website to perform the measurement tasks. You will not necessarily need all the results, and the order in which they are displayed on the site may not be exactly the same as the order in which the tasks are described. You need to choose which measurement configurations and results can be used to perform the calculations. In some cases, there may be several different but equally good solutions, yet in some cases a seemingly logical way of thinking leads to a wrong result. Therefore, always justify briefly, in one or two sentences, which measurement configurations you used to perform the given task and why.
Before solving the tasks, examine and interpret the measurement configurations very carefully! These differ in the jumpers placed and in whether DC or AC voltage is measured. It is a time-consuming job, just like having to actually configure the panel and instruments correctly in the lab.
A video about the measurement panel can be seen in the link below (copy the link text if the hyperlink doesn’t work):
https://web.microsoftstream.com/video/66bea126-a25d-42d7-9c1f-bbf4f9b1698c?list=studio
Measurement tasks0.
1.	Common emitter circuit (without feedback)

Using appropriate jumpers, set up the circuit corresponding to the above figure. Connect the power supply and adjust the supply voltage, so that on the cathode of the diode D (protection against reverse polarity) one can measure voltage +US .
1.1 	Measure the voltages of the operating point.
UB (Battery) =	
US (Supply) =	
UCE = 	
UBE = 	
1.2 Calculate IC, IB and B using the measured values! With a formula, specify the method of calculation and explain the principle of calculation briefly!
	
1.3	Connect a 1 kHz sine-wave signal to the amplifier input. Verify the operation of the amplifier by measuring the input and output signal with oscilloscope. Set the amplitude of the input signal so that the signal at the output be undistorted (CH1 = OUT, CH2 = IN).
On the basis of the equivalent circuit, measure with oscilloscope and calculate the values of the following parameters:
h11e  = ? How can the  condition be provided in the formula ?
	
h21  ≡ ß = ?
	
Voltage gain:
	
Output resistance, when an external load is connected by jumper JP15:
	
1.4 Analysis of the output voltage swing of the unloaded amplifier.
Connect a symmetrical triangle wave of sufficient amplitude to the input so that the amplifier is not overdriven yet. The following figures show the output waveform for voltage generator (measurement configuration #19, J1 ON) or quasi-current generator (measurement configuration #18, J1 OFF). Interpret the figures, explain the observed behavior and determine which waveform belongs to which measurement configuration.

2. Common emitter circuit with feedback resistor in emitter.
Set up the circuit shown on the figure below. In the following measurements make sure that the input jumper J1 is in ON position (i.e. short circuit of the 10 kOhm serial resistor).

2.1 Measure the operating point voltages of points B, E and C.
	
2.2 Calculate the actual value of currents IB, IE and IC. With a formula, specify the method of calculation and explain the principle of calculation briefly!
	
2.3 Using 1 kHz sine-wave input signal, measure the output voltage swing and the gain of the unloaded amplifier, as well as those of the amplifier being loaded by an 1 kohm resistor. Explain the effect of the 470 nF capacitor on the voltage gain.
	
2.4. Calculate the output resistance of the amplifier.
	
3. Analysis of the phase splitter circuit
Set up the circuit shown on the figure below. Connect a 1 kHz, 1 Vpp sine-wave signal to the input.

3.1. Examine the waveform at points C and E under no load and by applying a load of 1kΩ to one or the other point. Explain the observed behavior and choose from the figures below which of them belong to which measurement configuration. Determine which waveforms can be measured at point C and E.