Electronic Systems - Lab Report Example

Electronic Systems Lab Gain and Offset Circuit Introduction A build and gain offset circuit can be set up through two steps as follows Collect the preset and recommended (required) amplifiers Make a connection between the two amplifiers being tested Equipment The equipment that is to be used in the experiment includes: A Digiac 3000 operational amplifiers Signal generator Twin beam oscilloscope with probes Procedure Connect the circuit as shown: The circuit Circuit Analysis Stage 1: inverting Op-amp The components that are used in this amplifier R1 = 1 KΩ (kilo-Ohms), RF1 (variable resistor) = 20 KΩ Inverting amplifier Inverting amplifier used to convert and amplify input signal Vout = Vin Vout =  X 100 X 10-3 = -2 Vp-p Gain =  =  = -20 Stage 2: summing Op-amp Components used in this set up include R2 – 75 KΩ R3 = 75 KΩ RF2 = 75 KΩ Summing amplifier V1 offset = -2.5 V (DC) The inputs to the summing up amplifier are: V1 = -2.5 V V2 = -2Vp-p (AC) Summing up the amplifier converts the input AC and DC Offset voltage. By cancelling out the resistors of equal value, then: Gain 2 =  =  = -1 The total outcome of the amplification Gain 1 = -20 Gain 2 = -1 The total gain = G1*G2 = -20 X -1 = 20 Required for Mode A Measure the bandwidth of your amplifier, by locating the upper 3 dB point. Can you relate this to published data of the op amps used? Band width = 70.8 x 10 3 – 100 = 70.7 KHz Conclusion The experiment was of great use. I ensured that the gain and offset circuit used for calibration were the actual values used for the amplification. I observed that the input signal was in phase with the final output signal, which was derived from summing the Op amplifiers. The input signal used was a 100 mV adjusted from the signal generator by changing the amplitude of S.G. as having chosen the 1 K and 20 KΩ resistors to get the value 20 after summing up the amplifiers with the second op Amp being used to control the audio frequency (Bird 291). Lab 2: Filter Circuits 1 1. The response of a High Pass Filter is represented by: 2. The response of a Band Pass Filter is represented by: 3. A suitable schematic of a simple RC low pass filter is represented by: 4. A suitable schematic of a simple RC high pass filter is represented by: 5. A simple RC high pass filter has a resistor of 6.8 KΩ and a capacitor of 4.7 nF. The cut off frequency will be: c. 5 KHz 6. A simple RC low pass filter has a resistor R of 2.2 KΩ and a capacitor of 3.9 nF. The cut off frequency will be: a. 18.5 KHz Lab 3: In modern electronic systems its common to find both digital and analogue circuits with conversion of data happening based on the conditions of the circuit, i.e. Digital to analogue and vice versa. This experiment is designed to explore simple design principles of the digital to analogue Converter (DAC) via use of the R–2R ladder. Procedure A 2.5 voltage reference is used and the output is approximated at 7.5 on connecting a zener diode to the 10 KΩ resistor that provides 2.5 volts from the 12 V main power source. The DAC is tested by first connecting its digital input to the CK342A board switches and the following data is collected. Input switches Analogue output voltage S3 S2 S1 S0 0 0 0 0 0.0V 0 0 0 1 -0.46V 0 0 1 0 -0.93V 0 0 1 0 -1.39V 0 1 0 0 -1.86V 0 1 0 1 -2.33V 0 1 1 0 -2.80V 0 1 1 1 -3.27V 1 0 0 0 -3.76V 1 0 0 1 -4.23V 1 0 1 0 -4.70V 1 0 1 1 -5.17V 1 1 0 0 -5.64V 1 1 0 1 -6.11V 1 1 1 0 -6.57V 1 1 1 1 -7.04V To measure the output value by solving the equation: Output = X Vref Such as the binary code 1011, the output is given by =  X 17 = -6.093 V, and so on for all binary numbers The output shall fall within the rage of 0.46 V to 7.04 V Measure the current flowing into the R-2R ladder. The current flowing into the R-2R ladder is 0.25 mA Now connect the DAC inputs to the outputs of the 7HC193 counter on the CK34A, ensuring MSB is connected to MSB etc. Drive the counter from the on-board clock, labeled CK out. Select a suitable clock frequency. Observe the DAC output on the Oscilloscope. Measure the clock frequency and record in as much detail as possible (including photograph or sketch) the output of the DAC. The output frequency from the DAC can be obtained from the calculation: T = 6.8 x 0.2 = 735 Hz. The reading from the clock shows that the highest voltage recorded from the digital signal is 7.04 V and the lowest being 0.47 V conforming to the stated statement from the binary form calculations. Conclusion The digital to analogue converter aids in identifying digital inputs through an analogue and image technique. This experiment is an exhibition of how a digital signal is converted into an analogue output, which is helpful in solving and designing digital circuits in practice. Works Cited Bird, J. Electrical and Electronic Principles and Technology. 2nd ed. Burlington: Newnes, 2003. Print. Read More