Question

Need help with schematics for blocks 3, 4 and 5!!!!!!

Include all schematics and wiring along with the component values and how you acquired them. Explain how each block functions and label any figures.

Need schematics for blocks 3, 4 and 5!!!!!!

Goal For your final project you will be asked to design and assemble a system in which you will input a stereo audio signal, mix the channels into a single mono signal, amplify the signal, filter it to control the tone, and output it to a speaker. The figure on this page is a top-level block diagram for the project, and your system will have to meet these specifications. You will be using +9Vdo and -9Vdc power rails for the Op-amps instead of the usual + 15Vdc. This is so you could power your project with two 9V batteries if power supplies as you were originally shown. certain to use bypass capacitors on the necessary. Be Block 5 0.025-1 Vp 01-0.4V 1.2 V Block 1 Block 2 Block 3 Block 4 Block 1: Block 1 is a summing Op-amp circuit. It takes a two-channel stereo audio signal from the computer audio output. (The signal coming from the computer output varies with media player's volume control setting. If it is muted, the output is zero.) The output of Block 1 is a mono audio signal and is supposed to be in the range 0.01-0.4 Vpp. You should be able to vary each channel's contribution to the output independently, as in the last lab. Please use two 20 k2 potentiometers, one for each channel. Measure the computer output for a fixed volume control setting on the media player and start the design accordingly Block 2: The input to Block 2 is now a mono audio signal with a maximum voltage of 0.40 Vpp. This mono audio signal will contain various audible frequencies between 20Hz and 20kHz. Block 2, consists of a potentiometer controlled tone filter, and should have the capability of producing a variable gain for high audio frequencies which ranges between 3 and 1/3, while simultaneously producing a variable gain for low audio frequencies which ranges between 1/3 and 3. For example, if the input is a signal which contains the two frequency components 20Hz and 20kHz, in the output you should see the 20Hz component amplified by 1/3 and the 20kHz component amplified by 3 when the potentiometer is dialed to one extreme. For the same input when the potentiometer is dialed to the other extreme, in the output you should see the 20Hz component amplified by 3 and the 20kHz component amplified by 1/3. Note, vou are provided with the this handout and do not have to desi chematic on t Block 3: This is another 20k potentiometer wired as a voltage divider to provide attenuation (volume control) Block 4 In a previous lab we had a two LED voltage level indicator. If you extend this to 4 levels, that becomes Block 4. The input to Block 4 is a mono audio signal which will typically be about 400mVpp (but could be as high as 1.2Vpp depending on the input signal). For Block 4, design a 4 level voltage meter using comparators and LEDs. For the reference voltages, divide down the +9V power rail into references of approximately 120mVde, 80mVdc, 60mVde, and 20mVdc. These reference values were chosen to give a lively LED display for most music audio signals. Since the LF412 Op-amps used for comparators in this block are only supposed to be able to output 20mA, design this block assuming that 10mA will be the maximum current allowed through the LED when it is lit. Block 5: power amplifier with a fixed gain that is In this block you will be supplied the design for a capable of driving the speaker. This circuit will use a pair of power transistors that are of the NPN (TIP 31) and PNP (TIP 32) variety. These are larger than we need, however, the smaller transistors can become very hot if the circuit is not balanced correctly so we will use the TIPs. STYLE 1 PIN 1. BASE 2. COLLECTOR 3. EMITTER 2 It is a three terminal device. Transistor circuits can become complicated, but for our application the operation is very simple using two TIP transistors. For the NPN transistor, a small amount of current (thin ine -top figure) going into the base permits a large amount of curent to flow from the collector to the emitter (thick line). For the PNP transistor, a small amount of current coming out the base permits a large amount of current to flow from the emitter to the collector (bottom figure). The transistors are required in order to provide the necessary current to drive the speaker. The Op-amps do not have this capability on their own. The examples below demonstrate how we will utilize the transistor. Here B-25. This means that the current in the emitter and collector is about 25 times the current in the base. The arrows on the transistors represent a PN junction like for a diode, so there is approximately a 0.7 volt drop across the junction, but the Op-amp eliminates this issue so that the output follows the input (difference between its inputs is zero You can think of this as a powerful voltage follower. Note: you are only building one circuit with two transistors, an Op-amp, and a speaker. 9 v Speaker +9v 9 v Speaker 9 v Tone Control Circuit (the operation will be explained in lab) Ct 1 20k R1 use these values 3.5 R-202 2.5 15k 1.5 100 R35kn 0.5 10 10) 10 10 10 10 frequency (Hz)

Answer 1

3 23 s 2 (0.4 SRI RE # 20 k12 (+) con sdu frst stage op amp 60kn OK 3R a. C20k) on Now co n sider second ㅅtage op-amp 5ok 50k. OK 5ok ok