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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4
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166 views

Current boosting problem with 78xx

I've built a PCB with a 7805 based power supply on it. I tested the other parts of the PCB on a breadboard before I had the PCB made, but as the power supply circuit looked straightforward, I just ...
0
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0answers
27 views

Cascading LM300 series VRs?

Would it be ok or efficient to reduce a 120 volt to 44 volt transformer first down to 17 volts DC through a LM338T then again through a LM350T to output 9.5 volts DC so I can use an 4700uF 25 volt ...
-1
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1answer
51 views

200mA constant current @ 6V from 12V battery [on hold]

I have made a digital speedometer with a Hall-effect sensor, but while the battery is discharging, sensor output also changes. I need a circuit that consumes the entire battery capacity, that is, from ...
0
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4answers
53 views

Drop 12v supply to 6v to power a water pump [duplicate]

I have a submersible water pump that requires 2.5-6V. I want to power it from a 2A, 12V supply. I assume that's powerful enough, but the pump doesn't specify its current. How can I determine the ...
0
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1answer
91 views

how to provide a steady voltage, in case of source voltage drop due to heavy consumers in the circuit

I am designing an arduino circuit in which the power source is a battery connected to some heavy current consumers, these consumers are intended to work for short time and infrequently, my question is ...
1
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1answer
27 views

PWM input voltage regulation

I have a 12V DC motor that I plan to run in one direction with PWM input at 21A. However, in the other direction I want to drop the voltage to limit the speed. Ideally. the regulator would sit between ...
0
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3answers
71 views

Battery current reduction [duplicate]

I have made this circuit: Now I am trying to use this circuit in my bike. My bike has a 12V 9amp battery and while charging (bike running), the voltage fluctuates from 12V to 20V. To power this ...
0
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2answers
82 views

Switching Regulators in Series

looking for some help regarding switching regulators for a personal robot project. The problem: I have: two 18v 4.5Ah batteries (which when fully charged are actually more like 21v) I need: 5v/1A ...
0
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2answers
53 views

Clamping Voltage without disturbing the power supply

I am using a circuit similar to the following, to clamp the input to my microcontroller to around 5 volts: How do I make sure that the (5V) power supply is not disturbed and stays regulated. I am ...
0
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1answer
39 views

Minimum voltage rating for output capacitor for use with LTC3525-5 boost voltage regulator

I'm (still) selecting parts to build a 3 to 5V boost DC-DC converter using the LTC3525-5. The board I'm planing to build is based on the typical application shown in page 11 of the aforementioned ...
0
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0answers
53 views

Low current (~100ma) buck voltage converter simple, low cost options (48V to 12V)

I have 48V AC-DC power supply that I use to drive high power LED drivers. I also want to use the same 48V input to power a 12V fan and Arduino Pro Mini. Fan is rated at 0.25A but I could do without ...
0
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1answer
64 views

Different power sources for pcb

I have a project with arduino. Most devices are powered by the arduinos 3.3V source. But a gsm modem with 5V input and high current consumption cannot be connected with the arduino, because the ...
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4answers
128 views

How to drop 240V DC to 5V DC

I would like to drop a 240V DC voltage to a 5V DC voltage to supply electronic. The 5V stage needs less than 5mA in current. The solutions I looked at are: Resistor divider (Not really ...
0
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2answers
71 views

What should I use for a 3.3 voltage reference that sinks maximum of 1mA?

I am in search for stable and precise 3.3 voltage reference IC. I am using it for the temperature sensor application which only sinks 1mA at max. Can someone suggest me a best component/IC for this ...
0
votes
1answer
87 views

Can DC voltage be divided?

I have got an old camera that runs on 7.2V (2 cell li-ion). I only have a 4 cell li-ion battery. Is it possible to divide the voltage without using a DC-AC converter and a transformer? I have looked ...
0
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1answer
51 views

Battery pack for DSLR coupler

I am planning to make a battery pack, by using rechargable batteries, that i can use to power my DC-coupler for my DSLR camera. (Ref. Image) On my original camera battery it says 7.4V 1.2A but i ...
0
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2answers
74 views

Finding batteries to make a stable 12 V battery-power supply

I want to make a stable 12 V battery-power supply for RPi and LED matrix. Schematic is something like: ...
6
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3answers
274 views

Can I obtain a new voltage source from outputs of two cascaded linear voltage regulators in practice?

I have a device which works with 7V. I have a 7812 and 7805 already running in the circuit. Can I use the outputs of this voltage regulators to feed the 7V device? I know this is possible in theory. ...
0
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1answer
49 views

Battery supplying different voltage

I 'm trying to build a portable device running on battery. It needs power at 2 different voltage: 3v and 4.5v Is doing something like this a good idea ? if so, what type of diode should be used ...
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1answer
119 views

Two or more different regulators connected to one battery

I want to make batteries provide power to both a micro controller (Raspberry Pi) and a 4x4 LED matrix. A simple circuit diagram is shown below. (only one LED is drawn in the fig. But regard it as LEDs ...
2
votes
1answer
65 views

What will happen on regulator as battery gets depleted?

I want to make a 5V-power source with four 1.5V-AA batteries. I think it can be done easily with 7805 regulator. What I am concerning is the case that batteries are getting depleted as time goes by. ...
0
votes
1answer
32 views

Current of a circuit with regulator

When the specification of a regulator says that output is 1A for example the whole current of the circuit will be 1A? For example I have a regulator in series with a 100Ω resistor and a 7V source.The ...
0
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3answers
40 views

DC regulator ground with Arduino [duplicate]

If I wanted to control several ICs that exceed the current rating of an Arduino 5V supply pin with an external DC regulator (which also would power the Arduino itself), should the ground planes of the ...
0
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1answer
57 views

Ground type for DC regulator

When considering a simple DC regulator such as a Texas' LM22677 on a PCB, should it use the digital or analog portion of the ground plane? EDIT: Contextualizing, I have a 12V input feeding two ...
0
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1answer
95 views

*very* Low voltage regulator

I've been shopping for a voltage regulator that works in a range of .5-1.5 (+/-.5) Volts, but they are not easily found. I'm wondering if anyone knows whether they even exist, or possibly how to make ...
0
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1answer
67 views

Looking for good LDO regulator

I'm looking for a LDO regulator that will output 12v and provide ~2Amps, and has a shutdown pin/low quiescent current. I've seen a few but they run 4$+ a pop, is this common for LDO's to be this ...
2
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1answer
91 views

LM7805 and Zener Diodes

I'm boosting an LM7805 to 16V using Zener diodes in series at the GND pin (pin 2) of the 7805. The Zener Diodes I'm using are 1 of each of the following: 3.3V, 3.0V, and a 4.7V. Now theoretically I ...
2
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1answer
41 views

Amount of output current needed by voltage regulator?

I am trying to choose a voltage regulator. One of the metrics I keep seeing is output current, e.g. "Output current up to 800 mA". Does that mean the sum of current that the rest of my circuit ...
0
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0answers
23 views

Battery Charge Regulation Application

I'm building a switched mode power supply unit to take electrical energy generated by solar panels and store it inside a Lithium Ion battery pack. Some specifications: 1. The solar panel open circuit ...
0
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2answers
129 views

L7805CV won't go higher than 7.5

I am trying to use a STMicroelectronics L7805CV to increase voltage from 7.5v to about 12v, but I can't get it work. I've placed 470 ohm resistors between out and common and between common and ground, ...
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3answers
316 views

Power supply with LM723

I'm trying to troubleshoot a delinquent power supply I have. Most recently one of the transistors (Q1) actually exploded on it. This has led me into investigating the schematic, but try as I might, I ...
1
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1answer
79 views

Linear regulator LM1084 5.0V capacitors choice

I'm trying to make power supply for RaspberryPi and another one for usb hub and another for 9 Ping sensors(20mA)+ few servos + few microcontrollers like Atmega328P. I have only LM1084 or LM7805. So my ...
0
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1answer
51 views

How to set up a LiPo battery to be able to charge and discharge from the same circuit

I am new to using rechargeable batteries in electronics projects. To give some background on the context of the project, I'm trying to build a solar charger/power pack for a cell phone. My problem is ...
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1answer
67 views

LM337 negative voltage regulator gets very hot, is this normal? [duplicate]

I used the LM337 negative regulator to regulate a +12V from a PC power supply. And connected the GND to input and the +12 to ground of the circuit, and i got it work (i mean it's regulating the ...
0
votes
1answer
44 views

Voltage source for Vref or Voffset

I have a DiffAmp AD8132 following an OpAmp LT1818. A 1.5V voltage source, such as voltage divider, voltage reference, or voltage regulator should be connected to the B input pin of the DiffAmp to ...
2
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2answers
343 views

Do I need a heatsink for my voltage regulator?

I use L7805CV voltage regulator (TO-220) to get 5 V from a Li-Po 7.4 V 2200 mAh battery. However, after a while, voltage regulator gets really hot. Current measurement showed 200 mA. ...
0
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0answers
55 views

Request for comments on bipolar regulated PSU using LT1963/LT3015

I am a DIY amateur and try to build a PSU based on LDO linear regulators LT1963/LT3015. The driver to create the PSU myself are lower potential losses using these LDOs and lower output noise versus ...
0
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2answers
46 views

Getting closer to figuring out my battery requirements

I have been doing research for at least a week and am still a bit confused, but think I am getting to the point where I am close. I need to power 5V 3-5A. Some days this power source will hook up to ...
2
votes
1answer
214 views

Reducing Undershoot and Overshoot in a custom voltage regulator?

I'm trying to build a voltage regulator that takes in a reference voltage and an unregulated voltage (to power the components, and this voltage is always greater than the reference voltage) and ...
2
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2answers
429 views

What is CV & CC in power supplies?

In many power supplies, there's CV & CC indicators. What does they mean?
0
votes
1answer
54 views

Most efficient way to convert multiple voltages?

I'm driving a rgb led strip and an arduino from a variable power supply between 12-15 volts. So I'm looking at a buck converter for the 12v led's but I need 5v for the arduino as well. There must be a ...
0
votes
3answers
164 views

LM317 circuit capacitor question

I am trying to figure out the significance of the two capacitors recommended for use in an LM317 DC-DC converter circuit. Recommended circuit diagrams show that I should be using a 0.1uf Ceramic ...
1
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1answer
41 views

Determine the output voltage of an integrated ciruit

I'm planning to use an HPA674A (bq25504 EVM) which is based on the bq25504 IC to connect a device (wsn) that works from 2-3.6V which is connected to the Vstor pin and the storage element is connected ...
0
votes
2answers
47 views

MC34063 dc-dc inverting - capacitor question

For a project I try to build a dual supply for opamps in a device. I bought the MC34063 to invert the DC. The device should be portable, however, the standard schematic in the datasheet uses some very ...
1
vote
2answers
176 views

Current limiting voltage regulator to power 12VDC fans

I'm building a ventilation system that will blow air into the back of our parked SUV. Creating a plastic fan enclosure and installing the fans is no problem, but the electronics... well, that's a ...
6
votes
2answers
329 views

Supply three different voltages from the same pack of NiMH rechargeable batteries

I have a battery pack that I would like to use as a source for all of my battery powered components on a commuting bicycle. My pack includes (10) 1.2V cells wired in series: ...
3
votes
2answers
76 views

How does this shunt regulator work?

I'm investigating battery monitors and I'm looking at TI's BQ76930 to take care of an 8 cell 24V LiIon. They provide the datasheet for their evaluation module (PDF warning) which includes the board ...
2
votes
2answers
105 views

How do I use an adjustable LDO regulator to power devices with USB that usually use AA/AAA batteries (or should I)?

I want to use USB to power devices designed to work with one, two, or three AA/AAA batteries. Three seems to be the trickiest, because it involves dropping the voltage only ~0.5 V from 5±0.25 V to 4.5 ...
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2answers
92 views

DC-DC converter wrong output voltage

I needed a reasonably stable 6.2V power supply for my audio amplifier project. I've found a few AIC1563PN dc-dc converters (looks identical to MC34063 according to the datasheet) which I salvaged from ...
2
votes
2answers
294 views

Voltage regulator vs. voltage controller

I frequently meet the references to voltage-regulators and voltage-controllers. However, looking at the specs I find them to perform the same function. Is there a difference between the two, or ...