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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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7answers
3k views

How make a dual +-12V supply from a 24V SMPS

I'm trying to power a home-made load cell transmitter using a 24V single SMPS. I need to make +12, 0 and -12 Volts that are capable of 50mA. I wish to power multiple channels of opamps and bridges. I ...
0
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1answer
71 views

Battery volt to 5 volt

I have two 3.7 volt batteries (I can use one or two) and I need 5 volts. Initially I thought to use the lm7805 but the circuit absorbs 4 amprere. how can I do? I need the component to be as small as ...
0
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2answers
51 views

Electrolytic capacitor at negative voltage regulator input

I'm trying to use a L7912 to output -12 V DC. The datasheet says to use a 2.2 uF tantalum capacitor on the input for stability. Further it says if an aluminum electrolytic cap is used, to have it at ...
0
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2answers
70 views

LTC3624 regulator won't regulate

I am using LTC3624-3.3 regulator, with components as in the datasheet app notes - 12 V Vin, burst mode, 10 uF at in, 47 uF at out, 2u2 inductor rated at 2.3 A... At no load, voltmeter says 3.34 V. ...
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0answers
19 views

Voltage Regulatoe in OrCAD Capture

I’m trying to find a L78S05C voltage regulator in pspice to model in OrCAD capture. I cannot find it in a library but I have the data sheet. How do I create this component from scratch using the ...
3
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1answer
63 views

What is a typical reverse recovery time for a zener diode, or is reverse recovery time not applicable to zener diodes?

A little background.. I'm trying to understand how zener diodes respond to high voltage transients. I stumbled across discussions of reverse recovery time and I'm curious how it applies specifically ...
0
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2answers
47 views

What are some of the reasons for voltage spikes in voltage regulated DC circuits?

Decoupling capacitors are often used to protect ICs against voltage spikes even in circuits that contain voltage regulation of some sort (even something as simple as a zener shunt) What causes ...
0
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2answers
30 views

Regulator output current

What is the meaning of output current of the regulator. For example, IC datasheet's written as "300-mA Output Current Capability", the maximum output current must be 300mA, isn't it. What'll happen ...
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3answers
87 views

5V Regulator causing component damage [closed]

Im using a 5V OKI Murata DC-DC device to power an Arduino UNO R3 and a 4 channel 433MHz receiver. Ive got a 24V DC source which is a bench PSU at the moment. But ive noticed that every so often the RF ...
0
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1answer
51 views

What does it mean if my voltage regulator is acting as a wire?

When i connect 24V to my input pin, and connect ground pin to my Ground, it gives a short circuit at the bench power supply. What does this mean? Did i kill my voltage regulator?
0
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1answer
35 views

Thermal hysteresis of shunt regulator

What is the meaning of the "Thermal hysteresis" in shunt regulator datasheet ? Will it contribute to output tolerance ? FYI: It's TL4050C50-Q1 datasheet.
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1answer
62 views

Invert Voltage 0-2V

I need to invert voltage from the one sensor. So the ting is that I have DC signal from sensor: 0%-100% range of 0V-2V I need: 0%-100% range of 2V-0V I have LM324 level indicator and it is showing ...
0
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1answer
38 views

Voltage stabilizer for ESP8266 [closed]

I have bought an ESP8266 module with a corresponding relay module (https://s.click.aliexpress.com/e/baZSG3Pi - I couldn't find a serial number or anything for the relay). I connect the relay module to ...
0
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1answer
58 views

LDO, linear regulator or DCDC buck converter

I would like to power an ESP32 in my car, so the input voltage is between 11 and 15v, and the output voltage should be 3.3v to power the Arduino board. I thought that LDO were only for low dropout ...
0
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3answers
95 views

what voltage will 7805 deliver as output if input is lower than 5 volts, lets say 3 volts

I am looking at the 7805 specs sheet and there is one chart I find missing. It is the relationship between output voltage with input voltage, specifically when input voltage is lower that 5 volts, the ...
4
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2answers
79 views

Flyback Converter Capacitor Value selection with given ripple voltage limit

I need to design a flyback converter for my project. In my design the output voltage is 15 V. I calculated all the parameters including inductance values, diodes selection etc. However there is a ...
0
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0answers
35 views

Powering both sides of an opto-isolator from the same power supply rail

I have an opto-isolator circuit to drive a 12v relay coil that controlled by a microcontroller. The microcontroller power supply is 3.3v that generated from a 12v power source (using voltage regulator)...
1
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0answers
50 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 ...
0
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0answers
28 views

Limit voltage from a Peltier module to 5 Volts

I'm looking to make a simple device to charge my battery pack when I don't have access to an outlet. The Peltier module I'm thinking about using is a "TECI 4905" module that at first glance seems to ...
2
votes
2answers
116 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 ...
0
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0answers
32 views

Create small dropout voltage from a switching power supply

I'm asking my question in general but I want to give an example. I'm designing a gsm modem circuit that uses a single cell battery (3.7v) with a step-up switching regulator (XL6009) to generate 5v. My ...
0
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1answer
40 views

DC Battery Stability

I have a 12 V load that works by connecting an adapter from the AC socket and this adapter output 12v to the load. I decided to make a 12 v battery that can charged and the feed this load , all the ...
1
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1answer
30 views

Analysis of voltage regulator circuit

I have found out the output voltage to be 9V. To find power, we need \$I_CV_{CE}\$ We can find \$I_E\$ from the output circuit. \$ I_E=\frac{6}{24k}+\frac{9}{10} \$ But can we find \$I_C\$? Or do ...
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0answers
45 views

Allegro A4490 triple output regulator - unexpected output voltages

I am having problems with this schematic using the Allegro A4490 voltage regulator (home page, datasheet). Can anybody figure out what I am doing wrong here? I have no clue. I have been searching for ...
0
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1answer
36 views

Step-up (boost) voltage regulator

I recently purchased a step-up converter, the specifications state that it can boost 5 V to 30 V with varying input voltages. The reason I purchased it was because the charger for my handheld vacuum ...
0
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2answers
58 views

Why 7805c Voltage regulator drops the current if the current enters around 13mA to 7mA?

I know there should be voltage and current drop from the voltage regulator but my question is why current drops off ?
0
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3answers
67 views

Understanding power dissipation by LDO regulator as it relates to battery life

We are looking at using an AP2204K-3.3TRG1 to convert 6V from 4 AA batteries to 3.3V to power a microcontroller. I found that the efficiency of a linear regulator is (ignoring quiescent current) ...
1
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1answer
40 views

Voltage sequencing on power up

I'm pretty new on PCB design, so my question may be obvious for some of you. I am wiring the layout of an LCD screen on a PCB using kicad, when I came to powering up, the datasheet of the AT070TN92 (...
1
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2answers
77 views

Can I use series diode to drop voltage from Lithium Ion battery to ESP8266?

Ideally I would use a low dropout regulator but I can't. I also don't have access to a suitable buck boost converter. The best alternative I have (and also my plan B) is to boost the Li-ion battery ...
0
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1answer
39 views

How to protect equipment from voltage anomalies

My refrigerator makes some short anomalies in electric network in my apartment whenever it starts/stops its compressor. I'm not sure if it's a brief frequency change or voltage drop. I can notice this ...
0
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1answer
61 views

LDO voltage lower than expected

I have a 3.3V LDO TLV755 connected to a FTDI chip FT2232HL. But I only get 0.9V at the output terminal. I am not entirely sure what the reasons of this could be. When the FTDI chip connected with a ...
1
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1answer
61 views

Turn on/off ESP8266 by a transistor

I would like to turn off and on a circuit by another circuit. I believe that could be easily achieved by a transistor but when there is a voltage regulator and an ESP8266 with wide range of input ...
0
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1answer
42 views

Supplying power to PCB with USB voltage (2.5V) regulator [closed]

I am designing a normal PCB board. I want to put a USB voltage regulator to supply my PCB. I don't need to design the voltage regulator. I just want to add it to supply voltage in my PCB circuit. The ...
1
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1answer
58 views

Using Voltage Regulator (9v to 5v)

I’m trying to ‘hack’ a LED Fire-effect light bulb to work on a 9v battery. Using a multimeter I can see that the bulb converts mains voltage to 5v. I’ve got my hands on a 9v-to-5v voltage regulator ...
0
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1answer
66 views

12 V input to multiple 5 V outputs?

I have that project, where I have as an input voltage 12 V (lead acid battery) and would like to have 4 output of 5 V 1 A that would be switched on and off with a mosfet. I'm thinking which way you ...
0
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1answer
71 views

How does a rocking arm voltage regulator work?

I am trying to determine the suitability of replacing a (ancient) rocking arm voltage regulator with a modern digital device. I assume a rocking arm regulator has an electromechanical or magnetic ...
2
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1answer
60 views

Little help with this DE=A1D voltage regulator

So I bought this tiny Chinese camera module (cctv/fpv). It is supposed to take 5-12V, but the vendor states in bold red that it can only manage 3.7-5V. So far so good, I didn't intend to run it on ...
0
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1answer
35 views

How to deal with an inconsistent / noisy power signal?

I'm using a 12v power supply to operate a system of sensors that is very sensitive to fluctuations in the voltage input. Unfortunately, I can't control what goes on upstream of my components and this ...
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0answers
41 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 ...
0
votes
1answer
27 views

AC Power Splitter and Regulator

Is there a charging cable which splits into two? One of the split cable will have DC 12v 3a with a male coaxial 5.5mm x 9.5mm The other split cable will have DC 5v 3a with a USB Micro. Does this ...
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0answers
30 views

Voltage sensitive switch using CMOS voltage detector

I want to make a voltage sensitive switch which selects either ground or Vcc depending upon the value of Vcc. Here is a pictorial presentation: To detect the voltage, I am using BU4918 CMOS voltage ...
1
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1answer
54 views

DC-DC converter from 5 V input to 6 V with an output current of about 3 A [closed]

I wish to make a DC-DC converter from 5 V input to 6 V with an output current of 3 A or thereabouts using a 7806 regulator or similar. Is anyone able to supply me a circuit. A simple circuit would be ...
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votes
2answers
42 views

Is the tab on this voltage regulator D2Pak package connected to ground?

I have looked through the datasheet. The specific piece I am using is a MIC29300-12 with a D2Pak (TO263) package. I cannot find anywhere where it clearly states what the tab is connected to. ...
0
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2answers
54 views

Output current of TLV713 regulator

I'm using TLV71333P-Q1 to regulate the input voltage of 5 V to get the output of 3.3 V. It says in the datasheet that in normal operation, "The input voltage is greater than the nominal ...
4
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1answer
105 views

Using a zener diode and a bjt to regulate voltage received by a controller

Okay, here goes… I’m trying to create a circuit that will prevent low conductance (from rain water exposure) which occasionally shorts a particular switch, from triggering a controller input that the ...
0
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2answers
56 views

Does using voltage regulator in power supply further reduces the rippling?

I want to build a 12 V DC power supply. Which one is a better approach? If I have a step down transformer 220/12 volt and after doing its full wave rectification and smoothing its wave using ...
2
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7answers
2k views

Opinions on what I've come up with for a 12 V-to-5 V automotive circuit?

Is this a solid solution for an automotive 12 V-to-5 V circuit to power an ATtiny? I've been trying to come up with a solution for my needs that can handle the automotive environment that is so scary ...
0
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0answers
46 views

Can I connect switching regulator's EN pin directly to the car's ignition?

I am developing an electronic circuit that will be installed in a car and I'm wondering how I should properly turn the regulator on from the car's ignition (ACC) using ENABLE pin. I'm planning to use ...
0
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2answers
74 views

LM317 Soft-start circuit

assuming the below circuit is functional. Can you tell me how soft-start part is working? Would the same setup be valid for Vin=~3V and Vo =~1.3V, or would I need to change the C1 and R3. Also how can ...
1
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1answer
49 views

What is a safe max rated current percentage for a 1A, 5V positive voltage regulator like a 7805?

I have a simple circuit comprised of seven 5V relays and eight 5mm LEDs, if the supply is 5V, it will draw a max of 660mA DC. I was planning to use a 7805 positive voltage regulator rated for 1A, so ...