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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21 views

LD1117 / SO-8 heat dissipation

I'm new to SMD, and was thinking of using the SO-8 package for the LD1117V33, which I'm using to step down from 6v to 3.3v, running at about 50mA max. I was noticing that while the other packages ...
0
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1answer
31 views

Change output voltage of a 9.2V charger to 8.4 [on hold]

I had a head light charger. Its output was 8.4V 1000mA. The charger is not working any more. Now I need a new charger. But light company doesn't sell only the charger. Besides, they are promoting new ...
0
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1answer
42 views

Voltage Regulator Max 3.8v, Lipo cell ok?

I have a device (IC) with a built in DC-DC regulator that is rated for 1.8v - 3.8v with an absolute max of 4.1v. I would like to use this device with a lipo cell but, my understanding is that these ...
0
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3answers
97 views

How to: The basics of transformer VA calculation for voltage regulation using full wave rectification

Likely this procedure has been repeatedly discussed here. But I want to put the pieces together in this certain domain. So let's say we need to get +/-12V at the outputs rated at 1A using classic ...
0
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1answer
40 views

Voltage regulator for esp8266

Below is the link for the famous smt module ESP8266-12E. In the link appears the module and another component which package is 8 SOIC. I am thinking that it should be the voltage regulator for the esp ...
0
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2answers
82 views

Need some help to design power supply for custom Arduino PCB [on hold]

I am building a custom Atmel Mega 2560 PCB that will run off the 9V 600mAh rechargeable li-ion batteries in a bus. I need to supply - 5V for MCU and other components in PCB, the overall current ...
0
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1answer
94 views

Does 3.3v ground and 5v ground connected will affects circuit?

I have a wifi transciever(ESP8266) which should be connected to 3.3v and microcontroller connected to 5v(PIC16). For establishing the communication between the microcontroller and wifi they should ...
-3
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1answer
41 views

30-0-30 ACV 8A transformer to 12DCV [on hold]

Good Day.. I have a 30ACV 8A transformer. I urgently want to make a 12DCV battery charger from it. What are the components that I should use? Please also help me out with its schematic. Your help ...
2
votes
1answer
87 views

High voltage power supply and shunt regulator design

I'm building a high voltage power supply for a tube amplifier preamp and I need some advice. I need a power supply with a shunt regulator that is rock solid stable and dead quiet and outputs 600v ...
0
votes
1answer
33 views

Esp8266 - can I use a 3.7v liion cell without a regulator

I'm more of a hobbyist than a pro so forgive me if I'm asking the wrong questions however I have put some time into finding a solution to this problem. In essence I want to run an ESP8266(esp-12f to ...
-2
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1answer
30 views

MPPT and control charge(battery) [on hold]

I have a MPPT controller for my 16V, 0.6A PV panel. My problem: How best to use the MPPT to charge my 12V 7Ah battery? Will I need to use a seperate charge controller? Thank you beforehand.
0
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2answers
64 views

Voltage regulator 5v 1.5A

I have voltage source of 7v 250mA. Question is, when I apply it to regulator do I get 5v and 1.5A on the output of regulator?Or do I need 1.5A for a linear regulator ? How much current would I need ...
3
votes
3answers
103 views

Power supply filter choke failure - how and why?

Trying to repair a non-working Fiber to Ethernet Converter. When connected to power, the unit made a hissing/sizzling/scratching sound and the all LEDs glowed dimly. I isolated a small surface-mount ...
0
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3answers
87 views

Using Super Capacitors with solar cells and batteries to help save my dogs

I am looking to make a dog feeding mechanism that will operate regardless of power outages. The main point of this query initially is to figure out how to work with the materials I have (or can get) ...
0
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1answer
50 views

How to use a LM1117T-3.3 voltage regulator to convert voltage

I am doing a project where the components require 3.3v input instead of 5v, but my arduino pro mini can only supply 5v. Thus, I bought a lm1117t-3.3 voltage regulator to regulate the voltage, but the ...
-6
votes
1answer
73 views

I need 120 volts DC (yes, direct current) at 20 amperes [closed]

I need direct current at mains voltage--120 volts DC up to 20 amperes. I'm already aware of the plethora of full-wave bridge rectifiers that are capable of rectifying 20 amperes of mains power, but I ...
0
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1answer
63 views

Need help choosing options for 12V supply from a Lithium-Ion battery

There are lots of Class D audio amplifier modules for 12V use that are both readily available and inexpensive, intended for automotive use (hence the 12V rating). I would like to use one of these, ...
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1answer
57 views

Different between LM317, AMS1117, L7805

I am trying get a 5V to power up AVR micro-processor. The power source from 5V USB Power adaptor when indoor development. Also the AVR board will be mount to my motorbike and directly get the battery ...
0
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2answers
34 views

A dual-input solid-state switch that will reliably work in a car

I need a switch, but with a small twist. If it was operating on normal filtered DC I would know how to make one myself. But since it's for a car, I need help designing it for reliability and surge ...
1
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2answers
55 views

Internal reference voltage of Voltage Regulator - what does it depend on?

I know this might be somehow specific and narrow question but that issue bothers me. I've implemented the BQ24450 charger controller circuit presented in figure 10 of ...
1
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1answer
64 views

How to improve load transient response of an LM317 voltage-regulator powering an audio amplifier?

I am building a voltage regulator circuit for powering a pair of mini-speakers (about 3-5W) with built in amplifier and an old mp3-player/FM radio. The power source is an old mobile phone charger ...
0
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2answers
107 views

The “perfect” three terminal, 0.5A, voltage regulator

So I was looking at SMPS IC's the other day. I needed a couple of low current bipolar power supplies. I found these switch mode, three terminal voltage regulators. Like the old linear 78xx series. ...
0
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1answer
69 views

how to charge two 18650 3.7v batteries?

i have two 18650 batteries of this type (but with one 1500mAh and one 2000mAh) and i need to charge them with two (or more if needed) 6v 1A solar panels. I was looking around and found this but this ...
2
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1answer
112 views

Discrete voltage regulator

I was studying this discrete voltage regulator used in a guitar amp power supply. The filtered +-36V supply voltages go straight to the power amp, and if I got it right Q212-Q213 act as variable ...
0
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0answers
56 views

Question about voltage regulation

I'm working to build a system where I would like to measure air speed after it passes through a filter and I was considering this unit here: https://moderndevice.com/product/wind-sensor-rev-p/ It's ...
5
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3answers
310 views

LM317 µA Constant Current source possibility?

I want to create an adjustable µA Constant Current source using a LM317. It is typically stated to have a 5mA to 10mA minimum current for proper regulation. The On-Semi version linked above shows a ...
0
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1answer
58 views

Delay on DC-DC regulator

Circuit in picture is a simple regulator. I need to add 3.3V output delay-off for about 30ms. The reason for this is the battery can momentarily detached from the its contacts. I want to avoid a reset ...
3
votes
1answer
83 views

Can I ignore the Power up Sequence

I am designing a board where the datasheet suggests a power up sequence. Basically, the VDD_PLL should be turned on first, after 100us, the VAA should be turned on, followed by the internal supply and ...
0
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0answers
48 views

Is a resistor necessary if supply and LED forward voltage is equal? [duplicate]

I have a 3,5V source and LEDs running on 3,0-3,6V. Is a resistor still necessary? Using an online "led resistance calculator" tells me I will need a 1ohm resistor no matter the current.
1
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1answer
47 views

Buck controller MOSFET drive voltage

I am trying to design a switching regulator for LEDs, which uses the LM3405 as controller. This IC uses the BOOST pin to power the internal MOSFET driver, which controls an internal MOSFET. There are ...
0
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1answer
36 views

LM2940CT-12 output measuring 9.6V when relay used

So I've got a 12V pump, and a car battery, and I'm trying to regulate the 12-14V from the car battery to 12V output. When using just the LM2940CT-12, it outputs 12V on the dot. But when I use an ...
3
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2answers
76 views

LDO with a bypass option?

I want a board I'm designing to accept either 5V or 3.3V power as input. If 5V power is supplied I want to generate 3.3V regulated power on board. The rest of the board all runs off of the 3.3V power. ...
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5answers
916 views

Measuring temperature with ±0.01°C accuracy

What is the most accurate way to measure temperature to ±0.01 °C? I have looked into using a Wheatstone bridge (with a minipot for minor calibrations) and an RTD for its precision and range. I ...
3
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2answers
188 views

Does the following voltage regulator have a specific name?

The reference voltage is taken from the potentiometer.
3
votes
4answers
339 views

When to use a heatsink for a voltage regulator?

Sometimes in small projects Im using voltage regulators with outputs 8V or 5V such as LM7805. Power is I*V but Im wondering when really a heatsink is needed. Sometimes the current flow from the ...
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1answer
34 views

Series voltage regulator circuit impedance mismatching while doing multisim simulation [closed]

In my project,I have to design a series voltage regulator circuit with the specifications of o/p voltage as 9V,max. current as 1.5 A and short circuit current as 0.75 A.While designing the circuit ...
0
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1answer
38 views

Should I use an LP2953 to power an ATTiny85 with a 12v battery?

Like a lot of people I'm building a little transmitter unit with one of those cheap 433mhz transmitters and an ATTiny85, and I am having a problem with the power supply. Actually it is only the power ...
0
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1answer
108 views

Will connecting a 78L05 or 79L05 voltage regulator backwards fry it?

I got a SainSmart digital oscilloscope kit for christmas, and put it together according to documentation I found on the Amazon.com listing for the item. The markings on the board directed me to ...
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2answers
75 views

How can you cheaply make an output pin source/sink about 5 amps of 5vDC, 12vDC, 24vDC, and 120vAC selectively?

I'm working on a project and need to make I/O pins that are configurable to offer around 4 Amps or more of each voltage: 5vDC, 12vDC, 24vDC, and 120vAC. The pins need to be able to source and sink ...
1
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1answer
70 views

How much current will LM317 pass in this circuit?

The formula for the output current of a LM317 is: In this schematic, what will the output current be? simulate this circuit – Schematic created using CircuitLab MY approach: I ...
1
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1answer
94 views

uC-controlled high-side switch

I designed a circuit that powers on when the car is started (key is in ACC or ON). The circuit's uC then enables 12V from the battery by setting port PC5 high. The uC detects when the key is ...
0
votes
2answers
77 views

How can I supply 5v voltage to circuit in a portable way?

I have made a circuit which needs 5v to operate, I want to give 5v supply to that in portable and compact way. I didn't find any battery with 5v specs. I managed to run it with 9v battery in ...
0
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1answer
43 views

Negative voltage using boost converter

I am referring a schematic where 16V,10.4V,-7v is generated from TPS61040 R12 and R17 are used to set 16V from TPS61040 IC and zener diode is used to generate 10.4V. But how -7V is generated, I am ...
0
votes
1answer
42 views

Operational Junction Temperature with LM7800 series regulators

I am building a DSLR cooler (something I actually started last year, and ended up shelving when winter hit, and which I've picked up again for this coming summer), and I'm trying to regulate the power ...
0
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2answers
110 views

Power Electronics [closed]

I am currently building a wireless charger. I have difficulty in understanding the working of the regulator (7805) to which I connect the load and measure my output power. My power receiver circuit ...
1
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3answers
77 views

What is a good voltage regulator or voltage regulating circuit for my micro-USB battery charging needs? [closed]

I have a need for a voltage regulator such that I can use it to down-convert 5V USB to about 3.3V in order to charge a lithium battery. Ideally: Assuming some users may have a faulty micro USB input ...
0
votes
1answer
52 views

Two voltage regulators on same circuit

Would it work if I have a lithium ion battery that's connected to a voltage regulator that's connect to a Raspberry PI then another voltage regulator to a display?
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1answer
26 views

Sony STR DN1030 2nd volume control using a second Vr Encoder

First off, I am very, very new to any electronic physics/engineering. Here's my problem: I want a second remote volume control for my receiver that is wired to my desk. (I have already managed to ...
2
votes
5answers
86 views

LM2575 - use fixed as variable

The LM2575 is a simple switcher regulator for smaller currents/voltages. There is some fixed voltage versions (5,6,12V) and a variable. The most flexibe stock could obvious be the variable version, ...
3
votes
2answers
91 views

What trace length is considered short in case of buck voltage regulator

I'm working on LM2596 based voltage regulator circuit that will be printed on PCB. According to LM2596 datasheet some traces should be kept as short as possible. However no numbers are given. This ...