Amplifier Definition and 560 Threads

I know that a differential amplifier is used to effectively subtract one voltage signal from another (and amplify). However, are there any devices or techniques that can be used to electronically divide two voltage signals? Thank you

Homework Statement For the differential amplifier circuit given above, for all transistors except Q1 and Q2 we have: β=100, VA=80 V, RC =20 k, VT=0.026 (Thermal voltage), VBE(on)=0.7 V a-Determine the collector currents IC1, IC2, IC3 and IC6 b-Calculate the Differential mode voltage...

I have a question regarding an amplifier circuit that I’m designing. I was given a template to improve upon, and have made several changes to the circuit. Refer to the attached circuit schematic. Essentially, I need to create an amplifier that has a gain from 0 to 10 using an op amp that is...

Homework Statement The open loop response A(jw) of particular op-amp is measured and is shown. The top figure shows magnitude plot of A(jw) in dB and the bottom figure shows the phase plot of A(jw). Determine the value of β in order to have a stable feedback amplifier? Homework...

Hey guys. I'm jumping into the world of electronics out of boredom and curiosity and am trying to wrap my mind around a few things. I'm on the topic of Transistors presently and have spend many hours learning about it's different modes of operation. I'm a bit confused about the Forward Active...

Hi all, I am studying cs_mosfet amplifier and i have simulate one simple amplifier with VDD=+12v Vs=1v ID=0.5mA gm=1mA/v Vd=6v. I am getting a signal that is amplified by gain -11.3 by calculation and also on simulation but when doing on hardware i am getting gain around -40 to -45 I...

The outcome is: design a single stage amplifier with the following parameters: Rin=1KOhms Rout=1KOhms Voltage Gain=15 corner frequency=300Hz specified Transistor is BC109BP AC supply, 0.5V DC supply 20V supply frequency, not specified, I have assumed 1K We have not been given...

Homework Statement I need some help with the following problem (it is from an old test paper). Below is the Bode plot of the open loop gain of an amplifier: A constant fraction β=0.1 of the output is fed back to the input. This feedback does not load the amplifier. Using the Bode plot...

I need to design a unity gain amplifier for a sample and hold circuit. I've decided to use the circuit shown in the attachment. Now I know the gain = 0.5(Gm2*R1)[(Gm3*R2)/(1 + Gm3*R2)]. The 2N7000 has a Gm of 0.1, so that gets me the values of R1 and R2. I don't know if these are good values to...

Hi, I'm looking at a circuit of a classical instrumental amplifier having 3 opamps, 2 for buffer, with Rg to adjust the gain. The output from this buffer + gain circuit is then feed into a third opamp, in a circuit that is the 'basic' differential amplifier, but whose function now that Rg is...

Here is my circuit: β=100, VCEsaturation=0.2V, VBE=0.7V, λ->0, VT=26mV After completing DC analysis I got these results : IB=18.05μA, IC=1.805mA, IE=1.823mA, VCE=4.658V>VCEsaturation=0.2V, gm=0.06943, rCE=∞ Ω, rpi=1.44kΩ. After completing AC analysis I got Av=-115.7, Ai=72.23, Rin=1.040kΩ...

Homework Statement See ImageHomework Equations Source Transformations The Attempt at a Solution The answer is given, but I do not understand how they got it. When I multiply 9mA and 947.308Ω resistor, I get 8.526...what am I doing wrong? Also, could someone explain how they went on to get...

I don't understand why Q1 is on and Q2 is off. Can someone explain me the reason for that? Thanks in advance.

Hello, As I mentioned before, thank you for all the mentoring. It has been a huge help to my understanding. So, I am trying to stay one - two weeks ahead of my operational amplifiers class. I know that we will soon be discussing the 741 Operational amplifier. While reading about it, I...

Hello, Thanks so much for all the previous help. I will probably be using this forum a lot this semester because my textbook is not very helpful. So thank you in advance. I am trying to create a comparison table of CE CC and CB amplifiers to help me study. However, I cannot find the...

So I have a question regarding the gain of common emitter amplifier. Referring to the attached diagram, the voltage gain of the circuit is -RC/RE. However, I don't understand how Vbb can be removed when completing the analysis. I've done the KCL analysis by hand and keep getting a gain function...

Homework Statement I need to find an expression for the gain in this circuit. I know it is an interting amplifier, because with the models we were given to look at, this one fits the inverting amlpifier. I've also constructed a simulation in a simple Java applet that I have. My problem...

For BJT single stage amplifier we write gm=Ic/VT where VT is Thermal voltage whose value is 26mv. Now if we have a Darlington pair i.e. two transistor connected in CC-CC mode what will be overall gm. Will the collector current Ic be divided by 52mv or 26mv. (Because in gain equation gm comes)...

Homework Statement I need to set up a blueprint for my instrumentation amplifier on a breadboard shown on page 5 of the attached document Homework Equations The Attempt at a Solution I'm not sure how 2 op-amp chips will make 3 op-amps for the instrumentation amplifier. I'm also not sure how...

I'm currently doing a spectroscopy lab where you use a scintillator and Cs-137 to obtain a Cs-137 spectrum. I calibrated this spectrum using the known gamma energy for Cs-137 at 662 Kev at the photo peak. I am now trying to use this calibration for a Co-60 spectrum. The problem is that when I...

Homework Statement A typical transistor amplifier is shown in the Figure. Find the amplifier gain G. Circuit diagram: http://i.imgur.com/Rzv4JR7.png Vs = 280mV R1 = 100Ω R2 = 7kΩ R3 = 100Ω Vd = 4*10^5 Ib (Ib is current through R3) R4 = 7kΩ R5 = 900Ω Vo = ? (Voltage drop of R5)...

So here is my dilemma: We have our SR830 in a MOKE set-up. The modulation of the laser is with a chopper at approximataly 336 Hz. The reference signal is not being picked up by the SR830, but using the same cable the reference frequency is coming up on our oscilloscope. ie, plug the cable...

Homework Statement We have an amplificator of low frequences like in the figure.The transistor has these h parameters: hie=1.1k Ohm,hfe=50 Ohm In the entrance we have Vs and Rs=10 kOhm. Find A1,Ais,Av,Avs,Ri,Ri',R0 and R0' Homework Equations There are many. The Attempt at a...

I am talking about those 5pin AB amplifiers like the tda2030 for example. You can power them with posotive and negative 12v, which is equal to a total 24v, Or you can modify the circuit for a single supply, but if you do that so you can use a single supply12v, is it equivalent in output...

Determining truth of "555 watt" amplifier board My math is showing that this amplifier is not 555watts but 140watts at 8 ohm at +-36v and 555 watts when shorting the output with ground. What do you guys think? amplifier board...

I do a lot of electronics and have built high power amps at home, I am making one for my dad and I am putting the outputs on delayed relays so you do not hear the pop when the amp turns on and off, but I just remembered that there are other instances which will turn off the relay for safety...

BJT ,the output voltage is amplified because there is dc voltage supply to keep BJT active ,but what about the FET? The voltage supplied only control the gate only, anything to do with the output? Thanks

Homework Statement Homework Equations See above picture. The Attempt at a Solution I am stuck on the first part, i know i need to find the x intercept of the DC load line is at +Vcc, and I am pretty sure the y intercept is at Vcc/R7, but I do not know how to use this information to find...

Homework Statement Homework Equations See Image The Attempt at a Solution I am confused where to start this problem. Obviously i need to get at the DC load line for Q1. But the problem is that I was taught in class that the DC load lines intercepts for a transistor are...

So I had an old home receiver which broke down so i took out the large transformer 6800uf caps and rectifier. This receiver put out 60 watts out of each chip so from my many hours of being on google in the past, the chips should require +-35v, and because of the increase in voltage after...

Homework Statement Calculate the power drawn from the batteries by the amplifier. The batteries are +9v and -9v. The amplifier draws a current of 8mA from each of its power supplies. Homework Equations P = VI The Attempt at a Solution I'm just a little stumped as to what to do for the...

Homework Statement The following voltages are applied to the instrumentation amplifier in the figure. Vin1=5 mV, Vin2=10 mV, and Vcm=225 mV. Determine the final output voltage. Homework Equations R_{1}=R_{2}=R A_{cl}=1+\frac{2R}{R_{G}} V_{out}=\left ( 1+\frac{2R}{R_{G}}...

Hello, I have this audio amplifier from Vivax AM 100. But it has somewhat weird problem. When you turn it on it starts buzzing but, not like buzzing on speakers but rather circuit starts buzzing, rattling noise. There is also like wax residue on the board, which i don't think its...

I have a pressure sensor, it has 4 wires, In+ In- Out+ Out-. I excite In+ and In- with a 12V battery and the outputs are about 6V each, the difference is very small, 0.7mV at 1atm and 12.9mV at 100psi. I want to read this with a microprocessor which takes in analog 0-5V so I want to amplify...

Hi, I have a single 2 watt, 8 ohm speaker from an old radio that i wired directly to a headphone audio jack and tried it in my phone. as you can probably guess, my phones speakers are much louder. How could i make a basic transistor amplifier that could give decent volume from the speaker...

Hey all, Just a question concerning the image I have provided. If I have an offset of 0.1 mV at the non inverting input, how exactly does coupling take effect in this set up? If I input an ac signal, it will pass through the cap, but will the op-amp not still experience the offset voltage?

Hi, My understanding of shaping time on amplifiers is that its the amount of time the capacitor has to collect charge. I would say that the longer the time the better energy resolution you would have due to that all the charge created from the photon is collected. However, if the time is long...

So I want to make a tda2050 amlifier with 4 of these chips, and after posting a lot of questions about different audio chips here, the chips always turn out to draw a few amps EACH as said in the datasheet. On this chip it says a max of 5 amps and people always tell me to supply them with a...

I am using a transister model BC107bp in multisim, and i found that its min Hfe is 40 and max Hfe is 450. If I want to construct an amplifier circuit, i should choose the min or average? I found most of the datasheet show the hfe of collector current at 2m A (min 200 - max 450), but if my...

I just started to use a lock-in amplifier, and I am trying to following the procedures by adjusting zero phase. But my input phase changes with time and sensitivity, and I couldn't lock in onto it. The question is, is this normal that phase changes all the time during the experiment or if there...

Homework Statement The OP amp in the circuit is ideal. Calculate V0 if Va = 2V and Vb = 1VHomework Equations V = IR KCL, KVL, voltage division, current division,Op-Amp Output V = (Gain)(V+ - V-)(Gain) = -Rf / Rin Ideal op amp properties: Input Resistance RI = ∞ Output Resistance Ro = 0...

I am having some issues designing a simple amplifier circuit and was wondering if anyone could help me. I feel like I am missing something fundamental, but can't seem to grasp it. I'm using an AD826 dual operational amplifier using ±15 V supplies. I've breadboarded some very simple noninverting...

Homework Statement I am learning about differential amplifiers, and am having trouble determining the common-mode output resistance. In the text, we have the two sections "Differential-mode gain and input and output resistances" and "Common-mode gain and input resistance." Notice the lack of...

Hey...I was trying to design a practical of mine...There is this question where I am supposed to design a tuned RF Amplifier with gain 100 for a frequency 720KHz with BJT. I know that I will get frequency with LC tank circuit but the gain is a different story. I have searched 5-6 books and am...

Hey guys so I'm going to use this template because it said so in the stickies but my question isn't a word problem kind of thing. I am building an amplifier using this tutorial and am having problems. I have attached my schematic for it, however I'm fairly new to circuits and this project has...

Homework Statement Pretty straightforward. Attached is a small signal picture of a differential amplifier. Summing currents at the emitter junction, the text says: "Because the transistors have resistive loads, the output resistance will be neglected in the calculations." Why is this...

Hi, My question is regarding an example of a common-emitter transistor amplifier shown in my electronics book. Here is the diagram of this particular amp operating from a DC power supply: My book says: "the transistor has β = 99, with no signal applied the voltage at the base of the...

Homework Statement Problem statement and solns. in attachment. Homework Equations Can anyone explain the equation for the current gain Ai? I do not understand where the divider temr comes from. The Attempt at a Solution

Hi, The book I'm reading references the fact that the impedance seen by the inverting input of an inverting amplifier is just the two feed back resistors, R1 and R2 in parallel. I'm having trouble seeing this. I understand how the basic voltage divider with one end at Vin and the other...

I'm confused by the fact that for the typical non-inverting amplifier, (1) The input current is ideally 0 A. but (2) The current going into ground is given by Vin/R1 where R1 is the resistor above ground. If Vin were provided by a battery for example, which has Voltage=0V on one side...