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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regulator ac to dc with

I am studying for my EE exam ,I understand the general working of the circuit but there is some details about it I have to know. this regulator supply 24 volt with puissance nominale 200watt. it ...
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396 views

Is it ok to feed the output of one LDO regulator to the input of another?

Sorry if this is a stupid question, but I am mainly working with 5V PIC circuits and now want to integrate a component (nRF24l01+) that needs a 3.3V supply. As I have a box full of ~7V wall-warts, I ...
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1answer
71 views

Why is the LT1054 circuit providing far more than double voltage?

I created a LT1054 bipolar doubler circuit. I am using Linear Technology's chip. My supply source is measured at 6.1V. My finished circuit is providing -16.2V and +21.5V. Besides being far beyond ...
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1answer
52 views

Independent voltage sources using voltage regulators?

I'm trying to design a variable power supply, and need some clarification regarding using voltage regulators in parallel as independent voltage sources. As this is a power supply, one of the outputs ...
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2answers
79 views

What happens if the input of a voltage regulator gets out of the operating range?

I know that for a linear regulator to go into regulation, it is necessary to maintain (at least) a specific dropout voltage between its input and output. But what happens if the input voltage drops ...
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40 views

cmos inverter in voltage regulation

How does a CMOS Inverter drives the gate of MOSFET for voltage regulation? I have attached the image for clarification. I just want someone to explain me why two cmos inverters are connected to the ...
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49 views

APD bias discrepancy

I've built a PCB based on the voltage regulator design proposed here, Figure 6, which supposedly should result in a 30-90V output. However, the maximum output bias I measure is about 48V, which is ...
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0answers
37 views

Voltage regulation for HDD

I want to put together backed up power supply for diy NAS. The ARM development board accepts 12V and draws max 1A, no info on voltage it accepts. The HDD is Samsung HD154UI, specs say it draws max 2A ...
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1answer
21 views

Trying to make a current source with an XRP29302 (linear regulator)

I'm familiar with the configuration to make an LM317 (voltage regulator) into a current source. You connect a resistor between the Vout and Adj pins (Say 1.24 ohms) and draw the output directly from ...
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2answers
606 views

How does this non-isolated circuit create 12VDC from mains supply?

I took apart a PIR sensor, and inside it has a circuit similar to this (it uses the same chip): I don't quite understand how this rectifies and creates 12VDC. My understanding so far is the (68 + ...
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2answers
53 views

Ensuring common ground in a circuit with several voltage requirements

I'm working on a project that has components requiring various voltages. 3.3v --- to power a set of laser diodes (qty 24 @ 50mA = 1.2A) 5v --- to power a set of infrared transceiver sensors (qty 24 ...
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31 views

Replace Panasonic ML421 battery

I'm trying to replace a rechargeable ML421 battery in my old Panasonic FX100 camera. The specs of the old battery are here ...
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4answers
46 views

-12v Regulator selection & conversion

I need help in selecting proper Regulator for regulator IC for exiting hall effect sensor.Sensor exitation voltgae is +12 to -12 v . Usually i use 7812 1A for exite +12v , I would like to know is ...
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4answers
225 views

Why I=(V(in)-V(out))/R in zener resistor circuit

I am a hobbyist electronics student who try to study "The art of electronics" book. I am having trouble understanding below passage from the book? I am having trouble following what is going on ...
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5answers
1k views

How to reduce 5 volts to 4 volts 1.5Amp with minimum components used?

I am trying to reduce 5 volts high current source to 4 volts with at least 1.5 amperes. I searched the internet, but I could not find 3 pin voltage regulator, 5V(in) 4V(out)voltage regulator. I think ...
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1answer
54 views

DC voltage stepping down but keeping current uchanged with no regulator [closed]

Is there any way to divide DC voltage or stepping it down but keeping the current peak unchanged? But I can't use a voltage regulator. In fact, I want to make a regulator 5V output into 4.5 ~ 4.7 V ...
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1answer
56 views

How do I get multiple voltage lines from a single PSU output?

Suppose I have a regulated power supply that has +20V and -20V outputs, and an amplifier circuit that uses them. I also have a push-button (not momentary) power switch with an integrated LED which ...
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1answer
64 views

How does the power supply noise generated by digital ICs affect the output of regulator?

I have learned that the digital ICs would generate the power noise in the power supply line,however, I am not so clear about how. In my opinion, two contributors: the change of the current would lead ...
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1answer
109 views

Hold-up time calculation with high capacity MLCCs

I am designing a linear voltage regulator for 5V (from 30V) at 10mA for a low cost application. Everything works out so far, but I need around 10ms hold-up time in case of an input voltage failure. ...
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1answer
43 views

Maximum current draw from a step-up regulated output

I have a LiPo battery pack with 5V, 2.1A output. Now, let's say I boosted that with a step-up regulator like this Pololu module. At 12V output from the regulator, what is the maximum current I can ...
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1answer
122 views

how to protect a 12 volt operating DC LED Bulb from 230 volts mains supply

I have made a DC Led BULB (7 watt) which is working on 12 volts input. By the way its input voltage range is 12-48 volts DC (using BP 1601 regulator ic) Now problem is that when i gave some bulbs to ...
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2answers
79 views

Voltage regulator lm78xx for 220v?

I can see that the input voltage of the lm78xx series is 30-40v dc . We are looking for a voltage regulators system , that will get the 220v ac , and turn it into a : 3.3v, 12v, 24v, dc . I was ...
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1answer
42 views

eliminitaing spikes from the circuit input

Suppose I have a circuit which gets damaged for spikes and high voltages, so that I need to eliminate spikes and high voltages beyond a maximum value, so I have decided for the following two ...
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0answers
53 views

Most efficient way to generate 5.0 and 13.25 volts out of 2xAA

Working on an instrumentation device for some friends' lab. The MCU and most of the electronics require 5V @ ~15 mA, and 13.25 volts need to be fed to one side of a differential unity-gain opamp. The ...
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1answer
36 views

Pololu S7V8A strange voltage drop when connected to load

I've bought new S7v8A step-up/step-down voltage regulator which should give me on output 2.7-8V. However, when using multimeter I am adjusting correct value let say to around 5V (it really doesn't ...
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2answers
75 views

How does reverse leakage current of a Schottky diode come into play with a SMPS?

Looking at diodes for a low power switch-mode power supply I'm designing. I'm not quite sure what the reverse leakage current value is, or if it's relevant in the component selection.
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1answer
39 views

TPS54383 switching regulator components.

I'm trying to build a switching regulator using the TPS54383 dual output regulator, Now I've got most of the components and schematic figured out here. pdf Except the inductor's and diode; I'm ...
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2answers
117 views

Simple voltage regulator circuit with 7805c outputs very low voltage

I am trying to make simple voltage regulator circuit from my 9V battery to 5V using 7805c voltage regulator. The schematic looks like this: simulate this circuit – Schematic created using ...
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1answer
48 views

Spice simulation of a motor switching power supply

I'm designing a switching regulator for motor controlling, I have tried this circuit with spice but it does not work: The problem is that the voltage on the load of the regulator never goes down, ...
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1answer
38 views

How to calculate theoretically Output Impedance of a Linear Voltage Regulator

I am trying to calculate the output impedance of the following circuit, a linear voltage regulator. What is confusing me is the feedback coming from R1 and R2. I used R4= 500 ohms, R3 = 1K , R1= 25k ...
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2answers
63 views

About battery capacity and regulation

For a portable application, I would be using a single 3.7V 2600mAh li-ion cell. The circuit requires 2.5V to 5V to function with the current requirement being 100mA. So obviously a voltage regulator ...
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3answers
118 views

48V DC Power Supply Using LM7812 in Series

I want to create a 600W 48 VDC power supply with input taken from the line (220VAC) and so far the steps that I've had in my mind are: Stepping-down the voltage to 15V using transformer with 3A ...
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2answers
64 views

LM1084, should I leave the copper area connected to the TAB floating? [duplicate]

I am using the LM1084 in a DDPAK package as a 5V USB voltage regulator on 4-layer board. The TAB of the package is internaly connected to pin 2 (OUTPUT). I am not sure what to do with the copper ...
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2answers
69 views

Set ground reference of a 5v DC power supply to the middle of a 24v DC power supply

I have 2 isolated AC/DC power supplies. one generates a regulated 5 volt power supply and other generates a 24 volt power supply as you can see in the picture below: I also have designed a circuit ...
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2answers
64 views

mobile battery charging using voltage regulator?

Circuit shown at http://www.instructables.com/id/9v-USB-charger/ will that satisfy all condition of mobile charging through usb ? what is advantage of circuit shown at ...
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2answers
46 views

Adapter Write Protect for Hard Disk

I need to protect hard disk (sata) for read-only, like SD-card have write protect. Cable sata have channel A & B. Can i cut A or B??? Or any other way? Help me please! Thank everyone
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2answers
116 views

Need help with OpAmp and FET choice for a VCVS

I want to build a voltage controlled voltage source that will supply power to a resistive load (\$1.67\,\Omega\$, \$\approx\$ \$7\,\mathrm{A}\$ @ \$12\,\mathrm{V}\$). The load's dissipation will be ...
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1answer
70 views

We're making a bike-powered USB charger and we have (almost) no idea what we're doing

So my friend and I are going to build a USB charger powered by a dynamo. Here is a diagram of what we are planning to do. I have a few questions: 1.) How do we test if the dynamo and breadboard ...
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1answer
65 views

Building as Electrolysis tank and I want to regulate a 1.23v into the tank. Any ideas how?

I am building an electrolysis tank and I need some help. I am an architectural student and I have no idea how to regulate voltage or what battery would I need. I want to regulate from the battery into ...
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1answer
67 views

Buck regulator AOZ1014 getting burned

I am analyzing a buck regulator circuit as shown in following figure. link for datasheet given here: http://aosmd.com/pdfs/datasheet/AOZ1014AI.pdf I have few queries in schematic: Q1. In above ...
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2answers
75 views

What is the purpose of a Zener diode added to the output of a SMPS?

I studied circuit diagrams of some computer ATX power supplies. Some of them have got a Zener diode at the very end of 5V stand by line. The picture shows endpoint of the circuit - the SMPS is on ...
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2answers
70 views

Input to output differential voltage?

I came across this 7805 voltage regulator. In the datasheet is mentioned the current vs voltage graph. What is Input to output diferrential volatge?
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1answer
80 views

Low voltage DC Supercap UPS Design

Most generally I'm looking to design a UPS for a low power DC device given higher voltage AC current, with storage handled by a supercapacitor, or a bank wired in parallel. For my specific case I'm ...
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1answer
68 views

Low quiescent linear Voltage Regulator [closed]

For a battery powered circuit, I need a VERY low quiescent current voltage regulator. Input voltage is 20V lithium battery, output voltage is 5V (or 3.3V, precision not necessary) for a ...
1
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0answers
83 views

LDO Regulator Overshoot

I'm using an LP38691 3.3V fixed regulator which is overshooting. This wasn't an issue for years, but now a component is being replaced and the current on the 3.3V rail has gone up from 300mA to 500mA. ...
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1answer
58 views

1A Voltage Regulator - Maximum or output?

I want to design a circuit that has 12V1A output from a battery. I am using a 12V voltage regulator Do I want a 12V 3A Regulator or 12V 1A regulator? If a 12V 1A voltage regulator gives me a better ...
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45 views

Power with Battery + 1wire to i2C

I'm creating a project with Raspberry PI B+ where I will get energy from a truck (12~27v) or/and a solar power (6v 5.6w) to charge a battery and keep the device running until the battery finishes or ...
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0answers
35 views

AC to AC Voltage Regulater

Building a hobby related very small and simple project. Currently I run 120V through a household dimmer that feeds an AC to AC (3amp, 25.2VAC output) transformer. Problem is the circuit doesn't seem ...
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3answers
122 views

Can I put 2 voltage regulators (5V) in parallel to dissipate the heat better?

I connected around 10m of christmas light LEDs to a 5V voltage regulator (lm7805). It gets quite hot, put I can still touch it without burning my finger. So in is within its temperature range (120 C ...
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2answers
57 views

Simulating a linear voltage regulator with ngspice

I am trying to simulate a simple linear regulator using gschem and ngspice. However, my output voltage varies by over a volt as my input voltage goes from 10V to 20V. Can I reduce this swing in the ...