Questions tagged [voltage-regulator]

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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28 views

Rough calculations for heatsink and mains current

I'm designing a rectifier to output two voltages. Because of the output voltages, I'm using two transformers to get the needed input voltages as shown in the schematic below: simulate this circuit &...
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1answer
109 views

How to properly step down the voltage of a DC+AC signal that then goes inside a pin of a PIC?

The reason of the question is because i don't know if this is the correct way of regulating a signal that goes inside the pin of a PIC that accepts a signal that goes till 3V3. In the following image ...
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1answer
238 views

Resistor values on a 12v 10a circuit with LT3045 LDO

I am currently working on a project that aims to provide 12v 10a in the final output. I am quite new to EE and wasn't quite sure if I have choose the correct resistors value as highlighted in the ...
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137 views

using a step-up voltage transformer designed for 110V input with a 100V input

I relocated to Japan (where electricity is served at 100V) recently and I am looking to buy a step up voltage transformer to be able to use my TV which accepts 220-240V. While I managed to find some ...
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2answers
238 views

L7805CV - Circuit not pulling expected current when powering from Voltage regulator

I am using a linear regulator to step down the voltage for my microcontroller circuit, however, I noticed that when I power my microcontroller circuit from my laptop (at 5 volts) it pulls around 76 ...
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2answers
286 views

P-MOSFET Dropper-Switch - Linear Region

I'm repairing an ECU board from a SCANIA generator. It works with 24Vdc, and on the last maintenance the technician powered it with 220Vac, so it blew up some components. I've managed to replace the ...
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1answer
5k views

TP4056 lipo charger output voltage

for a project I'm looking for a charging solution to charge a lipo battery, while at the same time being able to power a microcontroller with 3.3v. For that purpose, I bought a few TP4056 boards that ...
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1answer
420 views

ac voltage regulator

I'm trying to built a circuit that amplifies music from a phone to a headset, based om ambient noise level. So if you're surrounded by noise, your music volume will turn up and in silent surroundings ...
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141 views

Why does my SEPIC converter output more power at higher temperatures? What are the implications of this behavior?

I have a Pololu S18V20ALV SEPIC voltage regulator board that is wired to a high-amperage 5V USB power source on the input and a DC brushless fan on the output. The output is set to about 5.5V. ...
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0answers
223 views

What is the purpose of the 7805 output capacitor?

How does a cap on a regulator output improve transient response? Is this cap not more appropriately drawn next to the load where it is not being defeated by intervening trace inductance? Or does this ...
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25 views

Boost converter output voltage abnormal

I use boost converter TPS61089 to generate 6V3A output from 5V power. My schematic is almost the same as TI's Webench's recommended schematic except for more capacitors on the input and output. ...
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1answer
61 views

Will this LM317 Circuit work for my application?

I am attempting to design a circuit to charge lithium 18650 batteries is a 3S configuration. I understand that a BMS is recommended, but I am not concerned with that. I have built this LM317 circuit (...
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54 views

Considering the inductor in a buck DC-DC converter, how to compute the current through it?

I've been stuck for a few days to the very first point of a lab in which we analyse the behaviour of buck and boost converters. The circuit is built by the university I study in, so there is no acutal ...
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1answer
63 views

Controlling high voltage pulsed load

I have designed a power supply that has two outputs, one at -3kV (200mA) and one at -6kV (10mA). A new design challenge has arisen that includes the need to pulse both of the outputs from nominal load ...
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89 views

Designing a circuit to replace AA batteries with a LiPo battery

I’ve been looking at ways to replace 2 AA batteries in an older device I have with a LiPo battery and USB C charge board so that I can easily charge it up and save on batteries. The biggest barrier to ...
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1answer
57 views

Use an Powerbooster 1000c as an ups for an RPi

I'm a pre-newbie hoping to some day reach newbie status. These questions are probably stupid but I would appreciate your input. EDITEDITEDITEDITEDITEDITEDITEDITEDITEDITEDITEDITEDITEDIT I'll try to ...
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1answer
38 views

Computer controlled potential difference across wires

I am trying to design a circuit to control the potential difference across 2 stainless steel wires. The two wires are connected together at one end (common node) and on the other end, one wire is ...
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0answers
121 views

12V voltage regulator

simulate this circuit – Schematic created using CircuitLab I have bought the LM78H12K 12V voltage regulator, for the 12V output. My input voltage is 17 V DC, but unfortunately this component is ...
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2answers
248 views

Feeding microcontroller and linear actuators (motors) with the same power supply

I have already made a diagram using a motor controller. The details of the actuators are: Input voltage: 12VDC Max Load: 750N(168.607lbs) Stroke Length: 16 inch Travel Speed: 12mm/s Duty Cyle: 25%. ...
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173 views

MP1584 5v regulator voltage drop problem

I was debugging the MP1584 module, 5v regulator circuit in the PCB. I have attached my debug circuit below. I have completed my circuit in breadboard and PCB also, but I was connected to any load ...
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2answers
185 views

230VAC to 230VDC converter for flicker free LED construction lights for use in videography/photography

We use LED construction lights for illuminating a photo or video set. As espected the lights flicker with the mains frequency. While in some cases this can be compensated with the right camerasettings ...
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1answer
188 views

Replace mains 12v power-supply with 12v battery

A Yamaha digital piano is powered by a mains power-supply. The power-supply states the following input/output values: INPUT 100-240V~50/60Hz 0.5A OUTPUT 12V === 1.5A (Where I have written === there ...
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3answers
97 views

Simpler ways to develop a buck regulator

I am designing a low profile space grade buck regulator. I have the following constraints ICs must be space grade Low component count Small size The converter specifications are as follows. Input ...
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0answers
59 views

Multiple source power supply

I am trying to design a micro-controller power supply that can use three power sources with a particular order of priority. The sources are: 5V USB - overrides all other sources when available 12V DC ...
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142 views

3.3V LDO Selection

If you've ever tried to find an appropriate LDO for your project you may have noticed the incredibly vast range available on the market. During my searches, I discovered this particular regulator ...
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69 views

Smart undervoltage protection

what is the simplest way to regulate the min DC voltage in a circuit? ...
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0answers
43 views

Voltage regulators on series PV panels

I'm trying to design a module to go on the backs of panels that will be connected in series. The module will have a few sensors connected to an FPGA and it will modulate a signal onto the line with ...
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33 views

Current Controlled Potentiometer

The core problem I am having is that I need to be able to control a DC to DC voltage regulator based on input from a 4 to 20 mA signal. The end goal is to have the output voltage of this regulator be ...
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0answers
134 views

Capacitor in the circuit - Bypass capacitor

I was trying to measure the supply current of a CAN transceiver during fault conditions, one thing which I noticed was that during CANH to GND(when the current consumption is supposed to be the ...
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0answers
75 views

Linear Regulator Operation

I have a linear regulator with three pins. It's identifier is LM7805. I've taken a look at it's datasheet and it looks unlike linear regulators I've encountered. Is the the op amp circuit included in ...
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1answer
65 views

Using an analog voltmeter to display the changes in out put made by a dimmer switch for a light

I'd like to preface by saying k know little to nothing about electrical engineer but would like help with making a lamp. I want to use a volt meter style gauge to display a different reading for a ...
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0answers
149 views

Vacuum tube voltage regulator - capacitor on the output

I'm thinking about building a tube-based voltage regulator to provide the power for the screen grids of the output tubes. I have seen multiple designs of this and am currently thinking of doing it ...
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0answers
48 views

Is current draw the same when powering a device directly from batteries or from a dc-buck converter?

I’m having a strange problem here: When I use two AAA batteries to supply a small slave flash, it charges in 10 seconds, with 1.4A instant draw for the first second and smoothly reducing current draw ...
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1answer
379 views

TPS63070 Buck-boost not bucking or boosting correctly

Can some check my layout since I am using TPS63070 buck-boost regulator and I would like to get 4.7V output at TP12 but I am getting 11.5Vwhich is wrong and don't know why? Base on the Datasheet R1=...
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1answer
691 views

Simple solar panel + supercap powered arduino

Long version (full story, so skip and go direct to questions below if you want to): I have small arduino mini pro board powered by 230mAh Lithium coin battery used as wireless sensor (with NRF24L01 ...
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0answers
105 views

SOT23 marking code SPR4

My search for the SPR4 lands me here but couldn't find a definitive answer. I'm leaning towards SP but that is pointing me to BSS84. The designation on the board is "Uxx" while others are 'Qxx". Thank ...
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2answers
206 views

Setting up a step down buck converter

I'm new to using buck converters. In the past I've just used a linear voltage regulator but due to heat issues in my current project I've decided to give a buck converter a try but I'm getting really ...
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0answers
282 views

USB Voltage auto selector (Prioritise VUSB)

I'm trying to design a auto voltage selector circuit to prioritise USB voltage when the USB is plugged in. The power goes through some voltage regulators which then powers a MCU (ATMEGA32U). I have ...
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0answers
131 views

What will be the output ripple current per capacitor buck regulator?

I have a existing buck regulator design. Converter part number: TPS54340Q1. Input voltage = 5 V. Output voltage = 3.3 V RMS ripple current is calculated as = 108 mA. (Don't worry too much about ...
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0answers
59 views

Stable 12V 1.5A

I'm in need of a stable 12V 1.5A power which I could carry with myself. One way of doing it would be to strap, say, 12x 1.2V rechargeable batteries and use LM317. But then I read about buck ...
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1answer
159 views

Resistor Discoloration

I am working with an existing design and seeing a 200Ω, 2W resistor becoming discolored in the field (customer questioned its condition), but not appearing to fail. I measure resistance and is 203Ω, ...
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1answer
396 views

Digital potentiometer, initial (wiper+start position) resistance compensation

In my project I am using a LT3086 (40V, 2.1A Low Dropout Adjustable Linear Regulator with Monitoring and Cable Drop Compensation ) With this voltage regulator you can "programm" the output current ...
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552 views

LM7915 Spice Model

I have some LTSpice model for LM7915 that I found in regulators.lib So, all nodes connected, and I'm getting the error saying: This circuit has floating nodes. ....
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0answers
40 views

Trying to identify part driving in magnetic levitator. Maybe a 2.5 V switching regulator?

Its from a toy magnetic levitator purchased on alibaba. I wanted to understand and modify it but the key component has the markings sanded off. I'm pretty sure I got the pins figured out and know how ...
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2answers
130 views

Discerning between transistor types

How do you tell different semiconductors (mainly transistors, sometimes even voltage regulator ICs, etc.) apart? Do they all basically look the same; or are there visual clues to indicate a certain ...
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0answers
611 views

SIM800l power-up problems

The datasheet of the SIM800l claims that currents can peak to around 2A during SIM registration and other network intensive activities. I tried powering up the module with the 5v output of a FTDI-USB ...
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0answers
1k views

Problem with Arduino Pro Mini and RC522

I have a problem with a circuit and I couldn't figure it out why is this happening. This could be a silly mistake by me cause I'm not really an electronic expert. So after spending some days ...
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1answer
71 views

Connecting 19v 3Ah projector to 4 linked power banks

I'm trying to make my projector mobile. As per the title the power adapter gives it 19v 3Ah. Now my idea was to link 4 10Ah power banks and take the 20v down to 19v, giving it about 3 hours of mobile ...
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0answers
369 views

Controlling the GND rail

Okay so I'm running into trouble with my small setup, and I'm not sure how to go from here. I've drawn up a very (terrible) schematic of what I currently have wired up: So currently, I have 12v ...
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2answers
139 views

varable speed on a 4.5v-12v dc hobby motor

How can I vary the speed of a 4.5v-12v dc hobby motor? This motor will run a set of conveyors to simulate a steel mill operation. The motor has small gears to run the conveyor, but i need to be able ...

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