A voltage regulator is an analog circuit that produces a stable output voltage that doesn't vary with input voltage or load changes. Switching regulators are much more efficient than linear ones.

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Studying Behavior of an EEG Device

I have an EEG brain signal measurement device. I need to calibrate it -- i.e., I need to be able to apply known voltages to it and see its output. After doing this many times, I want to be able to ...
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Power supply problems

I am building a +/- 45V power supply to drive a master-slave amplifier for a sonoluminescence experiment. I am following a stock design, and am having massive sag problems. The circuit powers up ...
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32 views

Voltage regulator bypass capacitor placement

At both the input and output (especially the output), I need to place several bypass capacitors (all MLCC). The datasheet for the voltage regulator seems to suggest that using a 10uF on both the ...
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35 views

i want to build a portable [on hold]

I want to build a battery operated charger.I was wondering if I could use 7809 volt regulator its hard for me to find 7805 volt regulator here and if I could step down the volt using diodes if use ...
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24 views

Connecting microcontroller to battery of working mobile phone

Is it safe to use battery of working mobile (ex. Nokia 6310i) through voltage regulator as power supply for MCU? If so, is it safe to charge phone while MCU working?
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1answer
59 views

Help with burning inductor in an LM2576 regulator [on hold]

I was helping a friend to design a constant 3A current source using an LM2576 to drive a load. Problem is that the 100uH inductor keeps burning every time the circuit is switched on. One option is to ...
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2answers
39 views

Optimizing regulator power circuit for low noise?

I am trying to understand the attached circuit. It's an ADP3333ARMZ-3.3-R7 regulator to provide 3.3V to an analog system. My goals is to have a very low noise regulator and power circuitry for a 16 ...
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1answer
47 views

Creating a simple voltage regulator for medium currents

Question, as fast as possible: Would this circuit regulate poorly-regulated +12VDC effectively? I am an electronics level zero, so please bear with me. Please let me know if you would me to clarify ...
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31 views

Building a 12V UPS [on hold]

I want to build a 12V (2.5-4A output) UPS (or something like that). I have a power supply of 12V and want to get a constant 12V out of it, but for 1-2 seconds (typically every minute or so) to an ...
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2answers
401 views

How do zener diodes regulate voltage? [duplicate]

So i read about the Zener diode voltage regulator circuit in the The Art of Electronics book, it made no sense to me, then I read about it in this article which was ...
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13 views

Repairing Raspberry Pi 3 [closed]

I recently fried my Raspberry Pi 3 by powering it with a UBEC over the 5v rail by the GPIO. Although it worked for a couple weeks it suddenly failed and my Pi would no longer boot with the UBEC over ...
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1answer
46 views

MCP16301 Step Down Voltage Regulator PCB Layout Validation

I'm looking for some feedback/validation that the layout for this MCP16301 is correct. I'm trying to get 600mA 3.3v Out from 12 input. I'm using the circuit as described in the datasheet on page 23 ...
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28 views

Solar battery trouble

I have an off grid solar energy system that is connected via a charge regulator to a battery bank consisting of 6 2v batteries. At the moment I have noticed the regulator going on to float really ...
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6answers
650 views

Rationale for operating the diode in the (reverse biased) breakdown region

For the circuits I've studied thus far involving diodes (which admittedly are not that many), they have been nominally used in the forward-bias mode. For example, the LED only lights up when it's ...
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3answers
218 views

Is it reliable to use Li-ion battery + LDO for analog circuits and 3.3v digital circuits?

I'm doing a project measuring ambient light with 'photodiode + op-amp + ADC + cortex-M0+.' For a while, I used stable DC source for providing 3.3v to every components. The next milestone is making ...
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2answers
64 views

Universal 3.3V & 5V power source for small device

I'm working on a hobby project which combines two modules that require 3.3V @ 130mA and 5V @ 100mA power sources. I want to make my device work at wide range of power sources - from single 3.7V ...
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1answer
50 views

How to pick resistor values for voltage range with potentiometer

How do I pick resistors for a 12v-30v boost circuit using an SDB628 IC; Vout= 0.6(1+R1/R2). I am using a 50k pot for R1. How do I get that 12v-30v output voltage range? To get 30V, my calculation of ...
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1answer
66 views

remote sensing in power supply

Can someone explain how the opamp compensates voltage drop for this circuit. lets assume that i need a 5V drop across load but instead im getting only 3V . how will the opamp make ouput across load ...
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2answers
58 views

PCB layout ideas for multiple voltage power lines

I am new to designing PCB boards. I have been working on a data acquisition board and it seems that four layer board will be correct way to go about it. But there are a lot of different voltages ...
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2answers
137 views

Using a MOSFET to generate a particular voltage

So ,i wish to cycle 1.4v and 5v through a sensor for 60seconds each. I have a mosfet STP90NF03L with Vgs(th)=1v (min).I am using arduino's analogWrite(pinnumber,value) to get 1.4 v output.. but i ...
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0answers
46 views

L200 regulator power supply circuit design help!

So here is the thing, I'm far from an expert in electronics, I'am pretty good with following a schematic but not designing one. I have made a power supply based of the LM317 that worked out pretty ...
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2answers
51 views

Turn on a circuit only when current reaches 500mA [closed]

I'm using small solar panels for charging mobile phones. I have two panels; each deliver approx. 19V 300mA. I used voltage regulators to each to get exactly 5V. Then they're connected in parallel. So,...
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24 views

SW-Reg voltages at points

I am needing a variable positive and negative output voltage ~(0-20)V with a 20+V input. To handle this, I am using the LT1074. I am using the two configurations from page 13. To do this, I am ...
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49 views

programmable AC voltage regulator

I have a testing setup where we have a manual voltage regulator that takes 230V AC input and outputs 50-230V AC. this goes then through a Power meter, then feeds a heating element. I use this to test ...
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2answers
76 views

Step up converter - voltage drop on load

I decided to build step up regulator to power DHT22 (temperature sensor) from two AA bateries. The DHT22 needs 3V (or 3.3V acording to some datasheets) for operation. I picked up MCP1625 (from ...
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1answer
73 views

choosing a voltage regulator chip

I'm designing a schematic for a system that will utilize plug-in daughter boards. I'd like to provide the daughter boards with high quality 12V, 5V, 3.3V, and 1.2V, with up to 5A, available via pins ...
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37 views

L200 with NPN pass transistor help!

L200 datasheet: http://www.zen22142.zen.co.uk/Circuits/Power/l200.pdf In figure 24: There are two transistors, one BDW51 and one BC108. I was wondering what is the use of the second transistor (...
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34 views

24VAC Power Pack Peak to Peak or RMS Voltage? (For Split Rail Power Supply)

I'm designing a regulated, current limited split rail power supply for \$\pm12VDC\$ and was thinking of achieving this with a 24VAC input plug pack/wall wart. I implemented the power supply with ...
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64 views

Are charge pumps better than boost converters since charge pumps do not use inductors?

Charge pumps use capacitors and not inductors. https://en.wikipedia.org/wiki/Charge_pump Boost converters require inductors. https://en.wikipedia.org/wiki/Boost_converter Both charge pumps and boost ...
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51 views

Understanding Thermal Stability and Drift in Linear Regulators

I'm considering 3-terminal linear regulators (LM317, LM350, TL783, etc.) for a power supply that regulates a 150V wobbly DC voltage down to 145V or 140V. My load is like 30-65mA. So, depending on ...
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2answers
53 views

Buck Regulator Supply From Multiple Sources

Hey Electrical Engineerers! I am currently working on making an LED tail light for an older car. Overview of the Taillight Each tail light has 4 inputs connected to it: Park, Brake, Turn, and ...
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40 views

Single Buck Regulator for Multiple Circuits

Currently working on a project that involves 4 separate circuits that light up LEDs on one tail light PCB in an automotive application. Due to the high cost of a buck regulator circuit, we have ...
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60 views

Adjustable Voltage Regulator Resistor Values

I'm working with an adjustable voltage regulator and am having a hard time understanding my equation for determining resistor values. Datasheet: http://www.chinaeds.com/zl/20103612559506780_AS2850YU-...
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41 views

Quick question about the L200 circuit limit

I need some help on how to calculate the output current.. Datasheet: http://www.zen22142.zen.co.uk/Circuits/Power/l200.pdf I want to use the (Figure 2. Programmable Current Regulator.) But i don't ...
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1answer
50 views

3-Phase Permanent Magnet Alternator with Regulator/Rectifier (SCR) Output Waveform

So I've been troubleshooting some electrical problems with a motorcycle charging system, and I need a little assistance understanding the output waveform: Per an article (which I don't have enough ...
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26 views

Does a shunt regulator protect other ICs from high current transient spikes?

Does a shunt regulator like 431L (datasheet), wired like this (VKA is not connected to anything) help protect other electronics supplied from INPUT net (battery connection)? INPUT net also supplies ...
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145 views

Arduino and GSM Module running on Li-primary batteries for years

For one of our projects we need to run an Arduino board + GSM module (SIM800C for example) for many years on batteries without recharging. The Arduino should be in power down mode for 99,99% of the ...
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1answer
85 views

LM1117 3.3 outputs 0.65 V

I have a small circuit with an ESP8266, a DS18B20 temperature sensor and a DHT22. I prototyped everything on a breadboard, and it worked fine. I then moved to soldering everything. My input Vcc is 5v, ...
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40 views

PSpice Simulation of CE8301

I have been working on a project that requires me to boost 1V to 5V. I have found a ready-to-use boost regulator that gets the job done. The problem is that I need to get the circuit simulated on ...
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2answers
266 views

How to step up unregulated ~0.2-1V to regulated 5V

For a school project, I am building a small hydroelectric generator. It uses a 10v, 600RPM/v brushless Tower pro 3520-7t-8 motor, which, when geared up (I'll spare you the calculations here), should ...
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2answers
87 views

Voltage Clipping with Two Series-Opposing Zener Diodes

Theory Schematic for Voltage Clipping with Two Series-Opposing / Bidirectional Zener Diodes Consider the following schematic for voltage clipping with two series-opposing/bidirectional Zener Diodes \...
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25 views

Atx power supply typical load distribution

I'm designing a low voltage atx power supply. I need to know what load distribution is typical between the voltage levels of an average gaming pc. For example I know most of the power is used on on ...
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2answers
61 views

Voltage reference for an OCXO

I have a no-name OCXO with pins marked by seller (VCC, GND, RF OUT, Vadj). I have checked its output frequency against rubidium oscillator using the following method: I connected them both to ...
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2answers
122 views

What R, C values to use in an RC Snubber to reduce output ringing in switching regulator?

I am using a simple buck switching converter (AP3211) to convert 5V-12V to 3.3V. The issue I am trying to resolve is the output ringing. I see a 800mV P-P ringing on the output, with a frequency of ...
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5answers
156 views

7912 Voltage Regulator [closed]

So my senior project is due Thursday and because of my extreme wits and knowledge I accidentally connected A 7912 Voltage regulator the incorrect way because I was unwary of the different pin-out. I ...
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66 views

Analog sensor behaves different when power with USB and Battery

I am using this analog proximity sensor with esp8266 (07)The sensor requires 5V. Whenever I power it with USB the readings are just fine (steady), moving my hand towards it and away from it reads the ...
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1answer
76 views

Decreasing Voltage of Power Supply via voltage regulator without using input/output capacitors

I have a HP laptop power supply 18.5V/3.5A that I intend to connect directly to LM7812 or LM7805 voltage regulator when I need to drop the voltage to 12V/5V. Since the laptop power supply (which is ...
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2answers
966 views

Why is there always a capacitor on input and output of a voltage regulator?

Looking at the datasheet I can see that the voltage regulators are not just a zenner diode inside, they are complex devices. I have noticed that there is always a capacitor at the input and another ...
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4answers
295 views

Regular (not Zener) Diode as Voltage Regulator

I see a lot of information regarding Zener diode voltage regulators but how about a regulator diode voltage regulator? What would be the potential drawbacks of using something like this: ...