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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Powering Raspberry Pi Zero W and LED-Strip with 24v DC

I have a RGB LED-Strip from IKEA that is powered with a 24v DC adapter. My Plan is to Power a Raspberry Pi Zero W and the LED-Strip at the same time from the same power source. My circuit looks like ...
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Help with circuit! 220v to 110v [closed]

I am in the US (110v) and accidentally bought an EU heating pad(220v) for a snake online. It has a dimmer switch control. I saw that the control box markings indicated both 220 and 110v on it so I ...
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About AMS1117 connected to 220v to 5 v regulator and making high pitch noise

I connected my AC to USB (220v to 5v1A) to an AMS117 with 35v47uf capacitor on its 3.3v output, hoping to power my ESP8266, the setting works, except for the fact that the voltage regulator start ...
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How do I change the output voltage of the LM7805?

I read in the LM7805 datasheet that I can change the output voltage to not only 5 V, but to another value by changing the circuit resistance. How do I do that? From what I understand, to change the ...
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4answers
519 views

Can I add 2200µF capacitor to regulator 5V?

Can I add a extra capacitor ceramic/electronic 2200 µF (actually working perfect from USB port laptop) for the test circuit for L7805 SMD? I need for peak current 2A SIM800C module. I don't know why ...
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2answers
88 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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66 views

Can I get 9 V out with a 12 V input from the attached regulator?

The 9V regulator in this datasheet has a 2V dropout voltage. However, in the electrical characteristics on Page 9, the datasheet says that you need 15V input to get a  9V output. Does that mean I can'...
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Choose regulator for 12V to 5V with 3Amp [closed]

I need help on choosing type of regulator base below design requirements Design Spec: Input Voltage = 12V Output Voltage = 5V max Current = 3A Power (12-5)*3 = 21W EX: Without heat sink 60C/W (...
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1answer
41 views

MIC5216 Achieve minimum quiescent current draw

I have the MIC5216 as voltage regulator. I am regulating 2 18650 down to 5v in order to supply enough power to my circuit. I am using a 328p as MCU. The chip goes to sleep and is awoken again by an ...
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1answer
65 views

Linear regulator after switching regulator

I need to power a board that works at 3.3V, and I have a regulated power of 12V. I tried to use a single linear regulator like the TS2940 but the power required is so high that the heat produced was ...
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2answers
99 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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1answer
95 views

Voltage regulator getting extremely hot

I've built a LED PWM controller according to the below schematic and the voltage regulator is getting extremely hot (I can't touch the heatsink). I've measured input and output voltages and currents ...
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1answer
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What are the differences between LDOs for positive and negative voltages?

I am trying to understand the negative LDO. I have the following questions regarding that: What is the main difference between positive and negative LDO? Is the reference voltage of LDO connected to ...
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1answer
82 views

LDO voltage regulator, no output

I'm making my own board based on Arduino. To power it I use one LIR2032 cell (button cell 3.6V li-ion battery) that's driven through 3.3V LDO voltage regulator. So far I have tried two different ...
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4answers
121 views

Can I use the power from a computer to run my board?

I have an industrial PC which has some usb ports, and I want to use that port to get 5V and convert it to the 3.3V (with decoupling caps). But now I need to use that 5V to drive 12 relays on my board. ...
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1answer
69 views

GPIO over voltage input protection

I want to design a circuit that can protect GPIO of the microcontroller from high voltages.the GPIO connects externally to mechanical switch. So my approach was to use zener diode to clamp the high ...
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2answers
83 views

LM317 Voltage Regulator multiple output where one is 12v constant and adjustable

Is it possible to output LM317 in a parallel circuit where there are 2 voltage and has a different output voltage where one is 12V constant and the other is adjustable using potentiometer?
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1answer
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Quiescent current vs GND pin current for Linear Regulator IC power dissipation

I want to confirm that, for a linear regulator IC, quiescent current multiplied by the input voltage accounts for the IC power dissipation(including drop-out voltage loss). I ask because the ...
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2answers
103 views

How to convert 0-3 V (PWM range) to 0-24 V (device voltage requirement)

I have an Arduino with some PWM pins, output range is 0 to about 3 V and I need 0 to 24 V range. I need to active a solenoid - a hydraulic proportional solenoid A 12V and 5V source is also ...
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1answer
45 views

Zener diode (Power rating exceeded)

The following is an exam question I encountered. In the above circuit the current across E is 180 mA. Since the current across 300 Ohm resistor is 13.33 mA, there will approximately be a current of ...
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3answers
70 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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1answer
22 views

12v Input LM2596 Step Down Module to USB 5.2V is Slow Charging

I am trying to use this regulator module (LM2596) to regulate my car's 12V power (constant from fuse port), and use the LM2596 output set to 5.2V to charge my phone (LG G6) but get the slow charging ...
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47 views

Is the regulator doing short circuit after enable?

Is it my circuit/PCB doing a short circuit after enabling the regulator? See image. (I checked the connection physically and is fine.) I don't understand why after enabling the regulator using the ...
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1answer
76 views

LM317 with potentiometer [closed]

According to above equation doesn't output voltage depend on input voltage? I have made this regulator circuit but it can't increase output voltage than the input voltage. So can't we increase ...
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1answer
29 views

Combining two power outs along with voltage regulator

I have two seperate solar panels with exact same circuitry connections. This is what I have: Solar panel -> Sparkfun Buck boost converter (set on 5v) -> TP4056 -> single 18650 AND + and - Power out ...
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48 views

How to decouple the grounds for two different switching regulators?

I've a single DC 24V battery supply, which I use as the input for generating separate 12V and 5V supplies. Two separate LM2576T ICs are used to regulate the voltage to the lower levels. However, the ...
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1answer
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How does an optimized car battery charging system could be designed?

To start, I saw a scooter electrics. In that implementation, after quite a weak (in my sense) generator it has some shunt linear regulator, that just dissipates overvoltage to heat. Oh god! Weak ...
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8answers
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This LM317 diagram doesn't make any sense to me

So this is the basic wiring for an LM317 as a voltage regulator, and very little of it makes sense to me. First off, if one pin is for my adjustment, why do I need \$R_1\$? \$R_2\$ will give me just ...
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1answer
40 views

Voltage regulators in series

I'm trying to figure out if my power distribution setup is hurting my circuitry. Below is a picture of the setup for one device: The power supply is a wall adapter rated for 6VDC/900mA output. The ...
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High amp multiphase buck

I am looking at designing a multiphase buck that needs to operate from a truck battery (24V) and has a constant output of upto 100amps at 24volts. We need to be able to set the exact amp draw with in ...
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2answers
41 views

What is the current draw during load on the LM1117 3.3v

I am looking at using the LM1117 3.3v voltage regulator. I would like to determine the current draw to power the regulator's function, during output of something near 650mA. All I can find is ...
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2answers
63 views

Guidance on the use of pins of LM1117

I plan on using this 3.3v regulator It has 4 pins on the SOT-223 package I plan on doing the following ( but want to check ) Pin 1 - Gnd Pin 2 - Vout - 3.3v -- Tied to pin 4 feeding my circuit Pin ...
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125 views

step up from 2 AA to 3.3V [closed]

I've read some related questions, but I was not able to find/understand a proper solution I'm using 2 AA batteries to power a SAMD21 MCU (arduino mkr series), a DS18B20 probe and a MCP3424 ADC. My ...
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139 views

Negative Voltage creating Sinking Terminal

For powering a RS485 circuit, I am requiring a Negative Power Source. I was thinking to split a standard power source with 0V, +6V and +12V, using the +6V as ground with LM7805, and using some LM7805|...
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1answer
26 views

how to use decoder and motor drivers to power individual motors at 12V? [closed]

I have a huge set of motors and they need to powered at specific times and at different voltage levels individually. Basic idea that I had, is to use a demux or a decoder to select the motors and then ...
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0answers
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Battery Protection + 3.3V regulation circuit - Weird Issues

I just got one of my PCBs back which is designed to work with a 3.7V single-cell LiPo pouch. The battery is currently at 3.88V I'm using a DWO1-G battery protection IC combined with an FS8205 dual ...
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1answer
72 views

How to regulate voltage across capacitors

This is a charging regulator, and with over voltage regulation across Cload, which is used to provide power for up to 3ms in case of a power micro cut. What I do understand in this schematic : How ...
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1answer
50 views

Using 4 AA batteries to charge mobile phone

There are three scenarios: 4 AA batteries connected in series would produce 6V. I'm planning to supply the output to an LM7805 regulator and produce 5V. The output from the regulator then will be ...
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5answers
154 views

Is it possible to use 7805 regulator without capacitors at its input and output pins?

I have to drive a magnetic buzzer whose current is 50mA and max. voltage is 6V. I will use 7805 regulator to drive it as my supply voltage is variable 9V to 24V DC. There will be another small load ...
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1answer
37 views

Voltage regulator STBY & OFF - whats the difference?

I am looking at MAX883 voltage regulator and from the documentation is not very clear whats the difference. It says this about pin OFF: In this mode, the pass transistor, control circuit, ...
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3answers
226 views

Understanding this power supply design

I'm doing some kind of reverse engineering to this very old power supply design. I'm having hard time trying to understand it all. I'm asking for some hints that help me read this schematic. From this ...
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1answer
89 views

LM337 voltage regulator outputs different voltage than calculated

I am using an LM337 to keep voltage stable at 3V from a battery supply (4x AAA). I've calculated R1 and R2 from the formula to be 100 Ohms and 140 Ohms respectively: ...
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1answer
59 views

LD1117V33 voltage regulator heatsink, thermal paste needed?

I want to screw a heatsink to my LD1117V33 voltage regulator. It's a normal 3mm screw and nothing inbetween. Do I need to use thermal paste or something like that? It will be regulating 12V down to 3....
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1answer
108 views

What happens if a part uses more current than the regulator is rated for? [closed]

I want to use a 5 volt regulator to regulate a circuit's voltage and the regulator is rated for 1.5 amps. If my circuit would use more than 1.5 amps, would the regulator just not supply it or would ...
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1answer
86 views

How to limit current using voltage regulator

I have a cheap little generic voltage regulator board which should allow me to select both the output voltage and the maximum output current, but I can't get it to limit the current properly. The ...
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1answer
57 views

Repairing an old Bench Power Supply

I have an old PS-303D from Conrad in use at home. Recently it showed a problem. If I measure with my multi from V- to V+, the voltage reading is correct, current and voltage regulation seems to work ...
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3answers
90 views

Zener diode purpose

Can someone explain what the purpose of D3 & D4 are in this circuit?
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10answers
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Would a 7805 5 V regulator drain a 9 V battery?

Doing some DIY as a hobby, I'm making a small humidity-temperature radio sensor. An ATmega328 is reading from a DHT11 sensor and then transmitting data to a Raspberry Pi by an STX882 radio ...
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1answer
55 views

Understanding Low Power Solution

I have a device that is powered off of a large battery. This device has peripherial ICs on it that consume power. Right now I have the input voltage through a switching regulator to 5 volts and then ...
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1answer
22 views

Small switching regulator EMI

Well, it's taken me weeks to think of a new absurd question but here I am at last. You're welcome! I'm looking at using a small, adjustable, switching buck regulator (likely a LM2574) for a very ...