# Tagged Questions

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114 views

### How to stabilize a control loop for an opamp-based linear regulator?

I'm trying to build a digitally controlled linear bench power supply. The idea is to have a DAC that will output a low voltage (in my case it's 0-2.5V) and then scale it (let's say 0-25V for ...
112 views

### Why consider Linear Time-Invariant systems?

Okay this could be a very silly question but I am asking it anyway. Why do we consider in most cases of signal processing that the system is Time-invariant? Is it because most signals are linear and ...
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### Linear motion - 50mm / 15 N

I need your help or advice. I need somehow to make a linear motion with stroke of 50 mm and starting force about 10N, the holding force after pull (stroke of 50mm) should be at least 20N. The holding ...
174 views

### When to use AC line filter

Since I work with equipment where sensitivity to AC is an issue, I tend to build linear regulated power supplies for my projects. What factors do I have to consider, to decide whether I need a line ...
130 views

### Optical linear encoder for motion tracking?

I need to find a cheap optical solution to measure the position of an object in relation to a surface. The object glides in a linear motion along an axis, around 30mm away from the surface. The ...
109 views

### Positive and Negative Voltage Regualtors

I was wondering whether I could use a negative voltage regulator, specifically a 7905, as a drop-in replacement for a positive one, 7805. On closer inspection of the datasheet, I realized that pin 1 ...
182 views

### Why is an electronic circuit system should be linear to use Fourier and Laplace transforms?

What I understood is, if we need to analyze a data from a system(such as damped oscillation or an output of an electronic circuit), the system must act in linear fashion to employ Fourier and Laplace ...
155 views

### Transformer output voltage equations?

I'm looking for equations on how to calculate output voltage of a simple power supply made of a step down transformer with Rs secondary resistance, a bridge rectifier and a capacitor with different ...
166 views

### Using LDO with Outboard Pass Tranistor

I need a power supply capable of supplying 7.5V at 6A using linear devices. To minimize power dissipation at this current level I have decided that using a LDO would allow me to lessen the power I ...
185 views

### Most efficient way to convert 6 V to 5.5 V

My goal is to design a USB charger for my phone/tablet when I don't have access to the power grid. I've used a LM317 with a 12 V, 5 A·h SLA battery but it does not provide enough capacity due ...
412 views

### Why is my MSGEQ7 circuit giving Arduino analog readings that are so high?

I have built the following circuit based on a proven MSGEQ7 based circuit design, which comes from the datasheet and elsewhere on the internet. I have built and coded to this circuit previously, with ...
403 views

### Designing stable PMOS voltage regulator

As a follow-on to the question "Using forward voltage drop of diodes with linear regulator" I am looking into designing PMOS voltage regulators. General Topology A common problem with the intuitive ...
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I'm currently researching LDO adjustable regulators to make an adjustable supply that runs from 5V. I want my supply to be capable of supplying down to 0V. I've found the LT3083, which can adjust ...
98 views

### Reduce heating in linear power supply

I have a linear regulator in a product which works from 20 to 240VAC: a two stage linear regulator. Stage 1 converts to 18V and stage 2 to 5V. Stage 1 starts heating up as the input voltage increases ...
400 views

### LM317 running digital pulses. Results are Noisy

The set up of my experiment so far: A. I use a simple LM317 linear voltage regulator to supply constant voltage of +5V to Vdd of my Laser driver circuit. B. Also I use another LM317 linear voltage ...
109 views

### When can a characteristic curve (here an amplifier) be considered linear?

I have built a difference amplifier and I have a pretty linear characteristic with a coefficient of determination of 0,9999478 (by a linear regression). Is it enough to say it's "pretty linear" (I ...
1k views

### Why does a multimeter show VAC on VDC power supply output?

I used my simple digital multimeter to measure the real output of several small PSU's I have got at home. They all should give just direct current and show some values in VDC mode, but the multimeter ...
1k views

### What's the difference between linear and audio tapers, and why should I care?

I'm stocking up on a variety of potentiometers to keep on hand for my audio projects, and I'm trying to figure out what to buy. The projects I'm working on seen to call for either linear & audio ...
452 views

### How do you directly determine the approx. value of internal resistance of inductor in LC circuit

According to my calculation, it will take 0.005 seconds to charge this circuit to 8 Volts through the 50 ohms resistor. Using $$V_c = V_s(1-e^{-t/RC})$$ How do you determine the effective ...
520 views

### RC Circuit, finding time it takes for Voltage across capacitor to rise from 0 to 5V

For the circuit shown below what is the time it takes for Vc to rise from 0 V to 5 V in (second). Assume Vc(0+) = 0 V The answer is $$t = 2ln 2$$ but I am unsure why. What I have so far:  ...
1k views

### Linear Circuit Analysis: Source Transformation

* source transformation is just a combining and rearranging voltage or current sources. I don't think its a universal term. and I'm stuck. any hint?
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### About SPICE: Should I use transient analysis or DC linear analysis?

My question is specifically linked to an exam problem where I had to find a function in terms of time for the current on a capacitor and a resistor. The circuit was very simple: A current time-variant ...
692 views

### Stabilizing opamps - am i doing it right?

I'm designing a high current linear regulator and learning about real opamps as opposed to ideal ones described in tutorials all over the net as i go. My initial voltage regulation design was ...
100 views

### TO-3 Transistor replacement needed that does not protrude through the chassis

I have a linear power supply that uses two 2N3771G. They are TO-3 style, and are exposed outside the chassis, on the heatsink. I need to move this power supply into a new chassis, for commercial ...
434 views

### Regulating a steam-powered model generator

In this age of questing for ever-more-efficient circuit designs, I have been presented with an anachronistic design problem: I need to keep a roughly constant load on a steam-powered turbine ...
246 views

### Linearized phase domain model of a PLL - what does a ratio of input phase over output phase mean?

I am trying to design a PLL and want to test it first in Matlab. I have seen that the phase of the input and output are linearized, but I don't understand what is defined by the input/output phase. ...
311 views

### Budget alternative to fancy linear slide

I have been checking out nice 1D linear slides such as this and this and this. Especially the first one is really nice since it has a built in encoder and a controller with RS232 interface. However, ...