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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51 views
Designing stable PMOS voltage regulator
As a follow-on to the question "Using forward voltage drop of diodes with linear regulator" I am looking into designing PMOS voltage regulators.
General Topology
A common problem with the intuitive ...
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2answers
103 views
Using forward voltage drop of diodes with linear regulator
I want to clamp the output of a adjustable three-terminal linear regulator Vout to -1.8V relative to a reference voltage Vref.
My approach is to use the forward voltage drop of three diodes but I am ...
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2answers
164 views
Power Supply Design - Multiple Voltage Regulators
I'm trying design a benchtop DC power supply for powering small projects, breadboards, arduino, etc. This is a list of what I want from it:
Fixed voltage rails for 24V, 12V, 9V, 5V & 3.3V
Edit: ...
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112 views
Its a good practice use dc-dc converters and linear regulators in the same design?
Its a good practice use dc-dc converters and linear regulators? Or its better don't mix them?
Better use all linear tecnology or dc-dc converters in "cascade" or dc-dc with multiple outputs?
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3answers
65 views
What can be causing output voltage to drop on LT1763 with very little load?
On a breadboard, I am using an LT1763 5V regulator connected as per the "Typical Application" diagram on page one of the datasheet (LT1763 DataSheet). From a benchtop power supply I give 12V at the ...
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1answer
46 views
what transformer should i use? [closed]
OK, i am new at all of this and for my first project i desided to try to use the power from a coal (like the ones you sprinkle incense on), use a Peltier to convert the heat to dc, now i know i need ...
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2answers
71 views
Warm voltage regulator [closed]
Why is my voltage regulator get warm while my car is not running "68 corvette" battery is also going dead, is it the regulator or another problem?
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1answer
50 views
0V Adjustable LDO Adjustable Regulator
I'm currently researching LDO adjustable regulators to make an adjustable supply that runs from 5V. I want my supply to be capable of supplying down to 0V.
I've found the LT3083, which can adjust ...
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4answers
113 views
Voltage Converter's GND Problem
I am confused about the ground part of a voltage converter.
This is a typical voltage converter. As you can see the the main voltage is 230V, and the output is 5V. Look at the output 0V, which is ...
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1answer
66 views
Can a linear regulator in shutdown mode have the output in parallel with a switching regulator
I am trying to design an efficient battery powered circuit using a 3.3V microcontroller (NXP LPC1343). One of the requirements is that the microcontroller periodically read a value from an ADC and ...
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61 views
Soft latch switch seems incompatible with boost voltage regulator
I am using a lithium ion battery to power a circuit board at 5V. I am using the LM2623 boost voltage regulator, which works fine when the battery is hooked up to the circuit board. I would like to add ...
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1answer
63 views
How step-down voltage regulators behave when their input drops below their output voltage?
How do the common low-dropout LP2950 and buck LM2596 regulators behave when their input voltage drops below their output voltage?
I'm driving a micro-controller board rated for 3.7-5.5 V with a 4.8V ...
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1answer
74 views
increasing output voltage of a schmitt trigger op amp
I have the Schmitt trigger circuit below that I read the output as 1.6V for the logic High. I wonder how can I increase the output voltage of the comparator below without changing the threshold of the ...
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4answers
150 views
Voltage regulator too hot to touch [duplicate]
I'm working on an RGB LED project. I'm using this as the power supply: https://www.sparkfun.com/products/114
It uses an LM317 which according to the data sheet can supply up to 1.5A. The LED's I'm ...
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3answers
102 views
Voltage supply clipping to <=3.3V
So, I have this circuit which needs <50mA and can be supplied with a voltage between 2V and 3.3V.
I want to supply it with a Li-Ion cell, which has 2.7-4.2V. I don't really want/need the ...
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3answers
115 views
Charging a low-voltage high-C capacitor. Efficiently
I'm currently upgrading my wind-up torch - upon opening it, I found the manufacturers had been quite sneaky in that the circuit is EITHER windup OR battery powered - worse, the batteries are ...
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1answer
64 views
What do LM78XX type regulators do with low input voltage?
If one gives less than the proper voltage to an LM78XX type linear regulator, what do they do? I'm well aware that there are no guarantees once you violate the specs given in the data sheet, but I'm ...
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2answers
62 views
Drive MOSFET from LBO output of switching regulator
Is it safe to use a MOSFET with gate connected to the low battery comparator output of this TPS61027 switching regulator in order to disconnect the load once batteries become low? The LBO is ...
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1answer
140 views
Voltage regulator with op amp(negative feedback) and MOSFET
The schematic above is a very good voltage regulator, excepting the high power dissipation for Q1 (also I'd use an NPN instead of a PNP). Can I replace Q1 and Q2 with a high current n-mosfet and ...
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2answers
126 views
Getting 5VDC from 6V (4S 1.5V AA alkaline batteries)
For my current project, I need 5VDC rail to power an ATtiny85, an RF module, and an Ultra-sonic range sensor, all of which require 5V. 5V ensure that the ATtiny85 can be operated without crystal at ...
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3answers
152 views
7805 5v Regulator outputting 5.8v? TTL chip not functioning correctly? LED + TTL chips?
I've read a number of other similar questions to mine, but none of the answers have helped me so far. I also don't have any electrical schematic software, so I'm afraid I'll have to explain in words ...
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1answer
86 views
Is it possible to increase voltage from a power supply without incuring great current lose
I have a 24V 4.5 amp(108 Watt) power supply. I know most Voltage regulators take a higher voltage and regulate it to a lower voltage.
Is there a way to increase the voltage of the 24V 4.5 amp(108) ...
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3answers
122 views
Rechargeable battery type recommendations for a 1-2 amp bicycle LED circuit
We are building a blinkey-blink circuit for a bicycle and not sure what battery to use.
The circuit will need to run on about 5V, since is is powered by ATmega chip which must run at 20mhz.
When all ...
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1answer
61 views
Help finding Buck/Boost Regulator IC
I have been trying to find a suitable Buck/Boost IC with certain features, but having gone through multiple Manufacturer's product tables, I can't find one that meets my needs. I think this is more ...
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2answers
153 views
I2C level shifting
I am currently designing a circuit that can record data from a sensor and save the data recorded into an EEPROM. My two devices (EEPROM and for testing purpose a RTC) are connected via an I2C bus to a ...
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1answer
107 views
Keeping the output of a heated LM317 constant
I have built a power supply using an LM317:
simulate this circuit – Schematic created using CircuitLab
When the supply is on for a rather long time (several hours) with a respectable ...
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4answers
254 views
Arduino Uno R3: Directly supply regulated 5V to 5V pin?
I'd like to use an Arduino Uno R3 battery powered a datalogger. I want do supply it directly with a Step-Up regulated 5V rechargable battery powersource at power ...
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3answers
174 views
How to build simple 12v .5a regulator
I'm building a solar powered light. The idea of this light is that its output is proportional to the brightness of the sun. At night, no light. During daylight, full light. So it's basically as simple ...
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1answer
192 views
Increasing input signal by 5V (Using 7805 voltage regulator)
I have an analog voltage input of 0-5V DC, and need a corresponding output of (IN + 5V) 5-10V.
My first thought is to use the +5V regulator to "step-up" the voltage directly, connecting the input to ...
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1answer
38 views
Regulated power supply from thermostat to zigbee module
I have a thermostat that outputs a DC power supply for a communication daughter board. When I read it with the voltmeter, it reads ~3.9v, but the zigbee module that I want to use requires 3.3v ...
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1answer
54 views
Linear vs Switching Regulator for Computer (22VDC to 12VDC @ 1A)
For a robotics project I need to use a buck regulator to power a mobile computer from a 22V LiPo battery. I am currently using this LDO regulator and am having issues with it getting very hot. Using a ...
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2answers
90 views
Arduino Mega 2560 - Stepping down voltage as input
Maddy from Little Bird Electronics suggested I go direct to the experts so here goes..
My requirement is:-
20 Rooms temperature to monitor
In Place:-
We currently monitor these rooms back to a patch ...
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1answer
179 views
LM317 running digital pulses. Results are Noisy
The set up of my experiment so far:
A. I use a simple LM317 linear voltage regulator to supply constant voltage of +5V to Vdd of my Laser driver circuit.
B. Also I use another LM317 linear voltage ...
6
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1answer
151 views
How do I decide what capacitor to use in a circuit?
I am using a voltage regulator and to get cleaner power, the datasheet recommends using a 0.33uF capacitor. However, it doesn't say what type it wants. Stupidly, I ...
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2answers
101 views
Voltage Regulation and Capacitors
Currently I am building my own AVR dev board, and I have been looking online about how to build the voltage regulator. I can build it, but I am curious as to why a capacitor is necessary. Also what ...
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2answers
121 views
Making a power supply that offers two voltages
I am building a model warship that needs 12 volts and 5 volts to run its motors and a microcontroller. The ship is powered by two 12 volt lead acid batteries wired in parallel. I built a power board ...
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2answers
120 views
Power Electronics for 3.3v or lower MSP430 + 10v sensor
After asking around I realized that switching regulators should be used to regulate the power going to the MSP430. I'm wondering (I'm not very informed in the topic of power electronics) how can I ...
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2answers
80 views
What formulas do I need to use to design a voltage regulator circuit for a zigbee radio?
I've written the code for my zigbee radios, but now I face the obstacle of getting them onto a carrier board to allow access to VCC, GND, TX, RX via a 4 wire connector.
The supply voltage is 3.712 ...
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1answer
345 views
Can I connect my laptop that runs on 18.5V directly to a 12V battery?
I have days of electricity outages here (due to war!!!) and I need to use my laptop. The thing is, it runs off 18.5V 3.5A (AC adapter output), so it is expecting 18.5V, what will happen if I connect ...
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4answers
416 views
9V to 5V regulated or 6V to 5V regulated? Which one is more efficient?
I have a choice of choosing 1x 9V Duracell battery or 4x AA Duracell batteries. I want to regulate the voltage to 5V with a 7805. From what I understand, the voltage regulators just converts the ...
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2answers
167 views
Should I use multiple voltage regulators?
I have five devices that need to be powered. I would like to use one DC source to power the four devices. Should I use voltage dividers, voltage regulators or a mixture of both? Also, any ...
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1answer
88 views
voltage regulators and capacitors
So I'm new to electronics and was looking at some Eagle schematics when I came across the following voltage regulator schematic:
My question is: would it be possible to change the regulator to ...
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2answers
78 views
Newb Voltage regulator pin-out question
So I just put my first complicated circuit together and of coarse it doesn't work, good news is I found the problem.
Given a LA5752 voltage regulator I assumed the hookup was pin1->Vin, pin3->GND and ...
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3answers
289 views
Simple step-up voltage regulator from 3.7V to 5V?
I have a 3.7V 4.4Ah li-ion battery and would like to use it to power my Raspberry Pi (which needs 5V and 700+ mA). What’s the easiest way to do it with minimum EE experience? Also, what resulting ...
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2answers
134 views
DC-DC Converter Power Supply
I'm looking to build a motor controller where I want to have consistent motor performance. Normally you have a 6v DC motor and you can plugin a 7.2v battery pack directly and be fine, but the motors ...
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3answers
386 views
How do you run a 5v MCU circuit on a 12v car battery?
My Archery club has asked me to design and build a Traffic Light system for shooting, but they want it to run on a 12v car battery as this is what our previous system ran on.
I'm going to make the ...
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2answers
78 views
Decreasing voltage without decreasing the current
I have got two 12 V 7.2 Ah lead-Acid batteries, which are connected in Series (26 V after charging). The batteries are connected to a step-up / boost module which have to be 2 V higher than the input. ...
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1answer
81 views
Powering the output side of a voltage regulator?
Would powering the output side of a voltage regulator cause any damage to it? (The ground pin would be attached as well) It will not be normally, but I am making a multi-voltage power converter and ...
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1answer
184 views
Simple circuit Voltage regulator question?
I am trying to build a simple circuit that takes a 9v battery through a voltage regulator that outputs 1.5v across a load resistor . The load will be just a piece of metal that gets heated up.
My ...
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5answers
489 views
7805 regulator outputting 4v instead of 5v
I followed a tutorial on sparkfun to put together 5v power supply. But for some reason I'm only reading 4v coming out of the regulator. I know it's not the regulator because this is the second one ...
