# Tagged Questions

40 views

### What are important parameters for an op. amp. used to AC couple and bias a sine signal to prevent noise/distorsion?

As I am not very skilled with analog design I would like to get some pointers to what to look for/avoid common pitfalls. I have a signal generator that outputs a sine wave. I want to center this sine ...
74 views

### Negative feedback with only passive components?

1) Negative/positive feedback with only passive components, whether this makes sense at all? Listing the book about signal processing i found
490 views

### Extracting the Square Root of a Voltage

I'm trying to discover a circuit that will produce a voltage which is some factor of the square root of the input voltage. I.e. $V_{out}(t) = K\sqrt{V_{in}(t)}$. The factor K is irrelevant. I ...
69 views

### AD8556 instrumentation amplifier not working!

I was wondering if someone would be willing to draw a complete schematic to help me get a AD8556 working. I currently have it set up like this: But the output just sticks at 1.58V. Bias current?
86 views

### Op Amp operating conditions

We all know that, there are two assumptions that can be made whe analysing ideal operational amplifers, which are: V+ = V- I+ = I- = 0 (no current flows through op amp inputs) but my question is: ...
159 views

### How does this blinking circuit with op-amp work?

Can somebody explain how this circuit works? The OP tries to make the same voltage at the input cables. At first, the LED is on. Therefore we have a low voltage (maybe 1V) on the negative input ...
464 views

### threshold problem on a Schmitt trigger op amp

I have the Schmitt trigger op amp on the below diagram. (channel A & B refers the oscilloscope probes on the following figures). The resistor values are selected to set the trigger threshold as ...
146 views

### increasing output voltage of a schmitt trigger op amp

I have the Schmitt trigger circuit below that I read the output as 1.6V for the logic High. I wonder how can I increase the output voltage of the comparator below without changing the threshold of the ...
54 views

i m trying to connect a de sauty's bridge(AC bridge) output to a precision rectifier. The problem is the output of the bridge (AC bridge) changes drastically to 5volts as soon as the connection is ...
767 views

### Economical thermocouple amplifier circuit

I'm looking for the most economical circuit that reasonably accurate circuit for amplifying the voltage produced by a thermocouple (so it can be read by an ADC). For the sake of argument, component ...
160 views

### How to justify that op-amp 1 has negative feedback?

Op-amp 1 is topmost in the schematic below. I used the ideal amplifier method (using A until the end and then lim A->infinity) and also the virtual short method. But I don't know if that's enough to ...
257 views

### Solving this op-amp circuit

I would appreciate some help solving the following circuit. I've been trying for a very long time and can't get the same answer the book has. I'm trying to get $V_o$ in terms of $I_{os}$. ...
153 views

### Degradation of AC signals as inputs of inverter amplifier circuit

i recently, did a configuration of an inverter op amp model and i fed it with an analog signal of the form$$S(t)=2sin(1000t\pi)$$ As you may know, the general response of an inverter Op Amp (741), is ...
42 views

What are the conditions under which loading can or cannot be ignored? I would like to be able to design a circuit in segments and then connect these segments together to create a circuit that performs ...
954 views

### What does this circuit do? Op-amp with transistors in feedback

I'm an electrical engineering student and I find this circuit in a guitar amplifier schematic, and basically, I'm just wondering what it does, and how one would go about working out what it does. ...
271 views

### Differentiator Circuit

So I have a circuit like this: With the output equation as: $V_{out} = -(\frac{R_2}{R_1})\frac{s}{s+\frac{1}{R_1C}} V_{in}$ So the question is to derive the time-domain equation in terms of the ...
440 views

### Drawing a Circuit from a transfer function

I need to draw a circuit from the following transfer function: $\frac{V_o(s)}{V_i(s)}= - \frac{100}{(1+\frac{s}{\omega_{p1}})(1+\frac{s}{\omega_{p2}})}$ I know how to derive a transfer function ...
1k views

### How do I calculate the gain of an op-amp summing amplifier?

So if I have a summing amplifier circuit like the one below: I know the Vin1, Vin2, and Vout value and the circuit is designed such that Vout = -(Vin1+2Vin2) but how do I calculate the gain? I know ...
366 views

### Inverted Amplifier Circuit not working

In a nutshell: The below circuit is not working. The signal is distorted and is not amplified. I expect it to be amplified by R_1/R_2. The op-amp is a TL071. So my question is, how do I get this ...
276 views

### Calculate transfer function with Sine generator

Given this circuit I would like to know how can I find it's transfer function. A method I've considered was to use Node Equations on nodes 1 and 2 , and I have a few things that I don't find clear ...
380 views

### What does this Op-Amp circuit do?

I am examining the st-micro rtd circuit for the STM32373C-EVAL kit. What does this circuit do? Can I use it to support both pt100 and pt1000 rtd elements? The circled area is the point of confusion. ...
333 views

### Peak detector is not working when voltage is changed

I am trying to design a peak detector in Multisim simulation tool. I have designed buffered peak detector to get peak voltage of sine signal. The designed circuit is working when signal voltage is ...
277 views

### Can you tell me how the op-amp in this DMM circuit works?

This is a autoranging DMM circuit. Specifically I would like to know what the lower op amp is for. It seems to be a non-inverting configuration with the (+) terminal at ground, but I don't what it ...
904 views

### How to analyze this circuit in the time and frequency domain?

I came across this circuit in another post and started looking at the op amp filter and how to apply traditional circuit analysis ( using 1/jwc for capacitors) and couldn't derive the transfer ...
791 views

### How does this voltage comparator work?

Can somebody explain to me, how the following voltage comparator works? I believe to recognise U4A as an inverting Schmitt trigger, but how everything fits together escapes me... Should the ...