Amp Definition and 377 Threads

In a pirani vacuum gauge the pressure is determined by the rate at which heat is conducted away from a resistance wire by gas moleculs. The heat is supplied using a constant current source and the rate of heat dissipation determined by the temperature induced change in the resistance of the...

Homework Statement Design a simple Op Amp circuit to find the position as a function of time of a falling body Homework Equations y=y_0+1/2gt^2 Assume y_0 = 0 at t=0 The Attempt at a Solution I used an integrator Op Amp with a triangle wave input. I chose the values of the...

Homework Statement Hi. Just like the title says, why is the output impedance of an op-amp so small? (as in physically, I understand why a low output impedance is a desirable characteristic)

In a 9v lithium battery, it has a capacity of 1200mAh. It is said quite frequently that it means 1200 mA in 1 hour or 2400 mA in 30 minutes etc. But how does it know how much to put out? Is it completely dependent upon the object drawing the current? If the answer to that question is yes...

So I did the first part, and got the gain as 11. I also did part c, and got approximately 80khz, but I'm not sure what to do for b). I know that at the 3db frequency, the voltage is at 1/20.5 of it's amplitude. So can I just use the equation f=(slew rate)/(2pi*A), and set A to 1V/20.5, and...

It was much easier scanning the pictures and problem than trying to recreate: I began by doing a source transform, making Vs = is*Rs, and placing Rs in series instead of parallel. I then did KCL at Vn. I tried to break the KCL eq down to il/is, but just ended up with some un-godly...

I have attached image. Thanks in advance.

Hi, I'm trying to understand how to correct when you put Vcc as 10V your max output is like 9.18V. Is there a factor on the data sheet or what? I'm trying to build a bi-state multivibrator to generate a 10V peak value but it's being saturated. thanks.

I am first year student 0f electronics and communication engineering. I have a course called basic electronics. I have already learn't bjt,jfet,mosfet,diff amplifier etc, now its turn of op amp. And I can't move on without knowing what is within op amp. Pictures shows Triangle and +,- within...

Homework Statement Please, I would like to know how to find the factor by which the capacitance is multiplied A picture of the Op Amp is here: http://en.wikipedia.org/wiki/File:Cap-mult-op.svg Zc is complex impedance of C Homework Equations none given The Attempt at a Solution...

I have found this circuit in my travels on the internet and it should suit my needs. I need to know what this configuration is called so I can calculate the resistors for the gain needed. If anyone knows of a similar circuit that has trimpots to adjust the 4mA to 1v and the 20mA t0 5v that...

Hi, In a common emitter amplifier circuit, I am considering the base-emitter junction. When you apply a base current, you get the base-emitter resistance, according to thermal_voltage/base_current. But when you get that resistance and place it in it's position in series with the emitter...

What will happen when the input voltages applied to the op amp is higher than its supplied voltage? Will it damage the op amp?

could one attach an op amp to a wifi transmitter to amplify the signal? thanks.

Homework Statement Describe the sum of two EM waves that have the same initial phase and same amplitude but different frequencies such that \omega _1 >> \omega _2.Homework Equations E=E_0 \cos (kx -\omega t + \alpha).The Attempt at a Solution I summed them up and reached, after an...

Hello Physics Forums community, I'm a new member and this is my first post. I have a circuits exam tomorrow, and though I grasp the majority of the material I'm having a hard time understanding the solution to a HW problem that I attached as a picture. Problem: Show that the circuit has...

For a lab we built the following circuit. Our photo diode was receiving a blinking signal which our op amp made visible on a DVM. I do not understand the purpose of the capacitors attached to the power rail. So far I understand how negative feed back with the Rf resistor controls the amount...

Homework Statement Hey there.. need helps here.. The question is.. Derive an expression relating the output voltage, Vo to the input current, Iin. The Attempt at a Solution i try to derive it.. but.. got problem with RL V1 = -IinRf Vo =- R2/R1(-IinRf) how to include Rl in my...

Hello all, I was wondering what the difference between a power amplifier and a preamplifier was. Someone told me that a power-amp provides current and voltage gain whereas a pre-amplifier only provides voltage gain. If this is the case, why are circuits like the following considered Class...

Hello, I am trying to design a foundation for an audio preamp that is powered by a single 9V battery. I am successful so far except the single power supply part. I am using the voltage divider scheme to get a +4.5V and a -4.5V reference voltages. With no load the supply voltages are close to...

Hello all. I was just wondering if it is possible to use an inverting opamp configuration with feedback to regulate an output voltage V0 without the use of BJT's? For example, the following sketch: http://img411.imageshack.us/img411/2389/opamp.png V0 = Vs * (R1-R2) /2R1 Mathematically, V0...

I am play with and op amp right now but getting unexpected results. I am trying to create a non-inverting amp. Here is how I have it hooked up: According to my calculations, I should be getting about 5.3 volts between the output and ground, but my voltage meter is showing 0.22 volts. Any...

I'm currently in the process of building a constant current source using an op amp. Circuit diagram: http://upload.wikimedia.org/wikipedia/en/9/97/Op-amp_current_source_with_pass_transistor.png I'm using a voltage reference instead of a zener diode. Currently the load resistance is 0...

For an inverting op amp with the positive input grounded, the equation for V(out) is (Vin)*Rf/Rin. Thats fine But what if the positive input is not grounded? What if there is a voltage applied to that input as well? How would I find V(out) when the positive input voltage is larger than the...

i have used different PSU on a simple electromagnetic motor (tattoo machine) and have notice a machine will run a certain way at 2 volts on one power supply but require 9 volts from another power supply to run the same. Question being is it the amp rating of the power supply that does this...

Power supply -- Importance of amp Rating?? Hello all: I have a TV tuner that requires a DC 7.5 volt, 500 ma power supply. I have a 110 V input power supply rated at 7.5 V DC 1,000 ma. Can I safely use this powersupply with the tuner. Analogy: I can plug a 3.5 am vacuum cleaner into a 15...

KW, Volts, Amp always confuse me. I have a project of 10kw generator, how do you measure that it is 10kw at first instance. for example if the output is 1200 volts, can it become 10kw or be a 10kw generator etc. What is the power requirement standard of a home ? how to fit the 1200 volt...

Dear experts, I am thinking of using an op amp to trigger a circuit. The +ve input to the op amp should raise '1' (high) if the voltage is 5v and not anything less. The -ve input to the op amp should always be '0' (low) and so i thin i short it to ground. I wonder what op amp should i...

In my search for an answer I found a post regarding car batteries but it didnt offer me anything I was looking for. My question, or the a step toward the correct question is how exactly are cold cranking amps on any particular battery determined. At first I speculated it was the amount of or...

Could sb explain to me how to calculate the 3db frequency of the inverting op amp, please? 1. For non-inverting op amp If Bandwidth gain product is 1.5x10^6 Hz and gain is 20dB then the F3db is given by Bandwidth gain product over 20. It equals 150kHz. 2. For inverting op amp the F3db is...

Homework Statement if the op amp satuates at +-14v, determne te the range of values of risitance R for which the op amp does not saturate. Assume the op amp is idal Homework Equations V-=V+ The Attempt at a Solution this is wa i have so far: (2-5/3)+(2-+14/R). not sure if it is...

please look at this circuit http://hyperphysics.phy-astr.gsu.edu/Hbase/Electronic/ietron/inva2.gif The transfer function for the the circuit above is Vout = (-Rf/Rs)*Vs if I were to switch the terminal of the op amp so that Vin is inputted into Vp and Vn =0 instead (everything is the same...

I'm using an opamp to amplify ac signals 40hz and up but there is still temperature drift, I thought drift was only a problem for dc signals? how do you get rid of temperature drift?

Homework Statement http://dl.getdropbox.com/u/119186/Picture%20122.png Homework Equations Voltage Drop = -I*R I1=I2+I3 Reqiv= 1/R1 + 1/R2 etc. The Attempt at a Solution I really have no idea how to approach this. A1 and A2 won't have the same current will they? I tried getting an...

guys I'm making this color sensor.i have used 2 RED LEDs as both sensor and emitter. I have used TL084 op amp in infinite gain mode because Sensor LED generates very small voltage. my problem is op amp is too sensitive so it reacts when i tough circuit or negative wire (some times even my...

Hello. I'm looking for someone having practical experience of cascading video amp like NE592 or LM733 in order to get wide bandwidth and huge gain.

What's inside an op amp? Is it just an npn transistor used for amplification? So can we explain it in the terms of base and collector current? Please elaborate simply (It's a high school project)

I just met a fellow who works in directional drilling. He has a problem when his dry cell lithium ion batteries die. It costs him $300,000 when it happens. What he needs to know is when to pull the batteries BEFORE this happens. These Double D cell batteries when connected, hold their 36 volts...

Homework Statement If y(x,t) = (6mm)sin(kx + (600rad/s)t + theta) describes a wave traveling along a string, how much time does any given point on the string take to move between displacements y = +2 mm and y = -2 mm? All known data are stated in above problem. Homework Equations I...

Hello, for technical reasons I'm looking for a schematic of an Op Amp built with discret components and having GBP over 30 MHz.

Do opamps have current limit, I have an OP-27 dual supply connected to 2 9V batters the battery measures 3 Amps and 16 volts is this too much current?

Why do two 6 volt batteries in series usually have more amphours then a single 12 volt battery?

If I run a 741C op amp with Vcc=+9v and Vee=0, will it affect the functioning of the op amp? Can I still use it as I normally would? For a 741C Vcc=|Vee|=13v.

Hello everyone, I'm just getting started in studying radio frequency design and have a question about amplifiers with a tuned circuit as the load. When setting the operating point of a standard class A transistor amplifier with a resistive load, one uses the collector resistor to set the...

please can anyone give me clearly information about Op Amp Offset Voltage with simple example and rule to explain that becaus i was found diffecalt to understsnd it .

Hi Can someone help me on how i can calculate the input common mode range for this pmos diff pair. I'd have an idea if it was an NMOS diff pair but am kinda uncertain of this. I'm looking for equations for the input signal ranges of Vmax and Vmin Thanks

Hi I was using a 50 amp hour battery and running something which is using 2 Amps all the time.. How would I calculate the time the battery will last ? Thanks!

When I connect 3V negative and 3V postive power supply to an OP07 op amp and I Connect a voltmeter to OUT of op amp and GROUND the voltmeter shows -1.8 volts why? I have connected anything to input I even tried shoring the input and this voltage is too high to be offset voltage. I Tried two...

Can anyone tell me how to calculate the common-mode input range of an instrumentation amplifier with all op-amps biased from +15V to -15V assuming all op-amps can swing rail to rail. Thanks.

Homework Statement i have this exam paper question. derive an expression for transfer function find expression for the magnitude and phase of the response i have attached circuit diagram below 2. The attempt at a solution i derived for first question Vo= 2RC(dVi/dt) -...