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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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Not getting 2.5A or 2 A DC current

simulate this circuit – Schematic created using CircuitLab I checking the output of the circuit's current by attaching multimeter(ON 10 A) in series with a load of 3 Ohms resistor. But I am ...
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1answer
22 views

12V Pump not working

I have interfaced a 12 V pump and a 12 V fan to LPC2138, there are 3 5 V sensors interfaced, according to which the fan and pump function. The whole setup is in PCB. There is a ESP8266 module ...
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43 views

The pros and cons of tantalum and ceramics in AMS1117

Task: Make a reliable power supply for sensors and an RFID card reader. Specifications: Total current consumption: up to 0.7A (700 mA.) Elements supply voltage: 3.3V Input voltage: 5V Working ...
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2answers
58 views

Voltage reference vs voltage regulator

I need to bias some op amp inputs with a voltage. I’m in the 10-60 hz range. I need the bias voltage to be as low noise as possible, like -155 dbv . Would a voltage reference, voltage regulator, or ...
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Looking for inductorless voltage regulator [closed]

I am looking for Multi topology, dual output and high out put current voltage regulator. Specifications are: Vin-12v Vout_Posive: +6 or +9 Vout_Negative: -6 or +9 Iout: Greater than 200ma so far ...
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46 views

Designing a circuit using an LT1073 DC-DC Converter

I'm currently designing a circuit to convert a 24V (±30%) to supply a 3,3V IC used to monitor currents. I need to use the LT1073 which has the following diagram. The operations of the component and ...
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125 views

Does it take/cost power when supplying in 3v to a “5v to 3v” regulator [on hold]

I have a boost converter that converts 1.5v to 3v, and I have a ESP32 that takes a USB input of 5V and uses a regulator to convert it down to 3v. If I provide 3v to the 5v input that goes via the ...
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41 views

DC-DC charging different voltages

I have several banks of batteries on a boat, two larger banks 48v electric propulsion system with regen 12v house bank Each has a charging source the 48 has regen up to 2kw while sailing The 12 has ...
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43 views

Dummy battery Solution - battery counter

I'm currently working on a project that will (hopefully) incentive people to stop using disposable batteries. To do that I'm thinking on creating a dummy battery that will allow you to plug a ...
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36 views

How to account for the low voltage when designing a Step Down Switching Regulator

Datasheet: http://www.ti.com/lit/ds/slvs569f/slvs569f.pdf Design procedure: **Essentially my question is say I have an input voltage that can range from 7-15V. When designing this converter (must ...
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4k views

How is it possible for this circuit to continue functioning correctly?

A circuit uses the RN5RT33A voltage regulator to generate the 3.3V rail. According to its datasheet the abs. max output current is 150mA, typical output current is 60mA. There's an add-on board that ...
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39 views

Generating +/- 7v from EVM DC 1854A

I am trying to generate +/- 7v from EVM DC 1854A, by default this evm can generate +/- 5v, by referring to datasheet of LT8471EFE using some formula we can calculate resistor values for generating ...
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28 views

Check for 2-LED system with a voltage regulator [closed]

I am trying to make a circuit with 2 LEDs and a voltage regulator to supply 2.5V Because this is my first time to use the voltage regulator, I am not sure whether I am using it appropriately. I need ...
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2answers
49 views

Replace 3.7V flat tablet battery with a 18650 cell

I am building a device using cheap Chinese tablet. One of the problems I have is weak built-in battery. I'd like to replace it with a few 18650 cells. As far as I know, 18650 cell can be charged up ...
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2answers
89 views

Negative Voltage Converter

I need to generate a negative voltage of approximately -12V from a 12V power supply. I read about ICL7660A that performs supply voltage conversions from positive to negative for an input range of +1....
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1answer
108 views

Not getting 5V output

I am trying to build a 5V constant 3A DC circuit. As stated in this datasheet: http://www.ti.com/lit/ds/symlink/lm338.pdf on page no.15. According to calculation R2= 1.28 ohms, but I don't have it I ...
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24 views

(Very Basic) Confused on Reading a Datasheet and Calculating Inductor Ripple Current for a switching Regulator

I am using this component for a project, however, when reading the datasheet I have just become confused about a couple of things. Datasheet : http://www.ti.com/lit/ds/slvs569f/slvs569f.pdf I am ...
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1answer
68 views

Whats the difference between one terminal power source vs. two terminals power source in circuit simulators?

I found a step down voltage regulator circuit online and tried to simulate it and noticed that it runs when I use the one terminal power source and it doesn't run when I use the two terminal power ...
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2answers
32 views

Can the same capacitor be used to support multiple LP2950s in the same circuit (as Cin)

I am using multiple LP2950s in the same circuit. Can the Cin capacitor be the same for all of them (the same physical device)? I wanted to reduce parts count by using the same physical capacitor for ...
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2answers
37 views

12v input vs 7815 voltage regulator outuput

I've made a quick test where I put 12V from a dc power supply to a 15V regulator - so the "input" was lower than the voltage regulator output. When I measured it, I had a 5V output, and it was what I'...
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1answer
73 views

Powering phone using LDO regulator on battery terminals - what reservoir cap to use?

I have rigged up an old phone that does not run without a battery by attaching an AMS1117 regulator to the battery terminals. The regular is fed from +5V USB, and outputs 3.3V. The regulator comes on ...
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2answers
93 views

Safe voltage for hydrolysis of water - teacher demo

I am a science teacher and looking to perform an experiment with my students. I do not have much background in electricity. My students will be performing hydrolysis of water using a 9v battery. ...
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1answer
44 views

Improving load regulation on voltage regulator

Basically, I'm building a device that powers a number of LEDs; each LED needs to have as consistent a power as possible (each eats 25mA at 3.3V) across the number of LEDs being lit up. I'm using a ...
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2answers
69 views

buck dc dc step down with LT1054C

I built a simple circuit to produce -5V from regulated +5V but it doesn't work unless the voltage is at least +6.5V as input. The LT1054C shoud work ok from 3.5V but I measure 0V at output with my ...
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101 views

3.3V LDO Selection

If you've ever tried to find an appropriate LDO for your project you may have noticed the incredibly vast range available on the market. During my searches, I discovered this particular regulator ...
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44 views

Trying to identify a battery and its controller

Attached are two images of the inside of one of those devices to extend the battery life of your phone. This one was a promotional giveaway and only had their logo on the outside. I tried searching ...
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72 views

Could a blown voltage regulator still supply electricity?

(I'm new to electrical engineering, both the website and the topic, so don't hesitate to correct me) I'm building a very tiny form factor transformerless power supply with 5 V output. I was ...
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73 views

Why the replacement of 7812 with R-78E12-0.5, DC/DC makes the circuit not working?

I have this simple surge protector and soft start inside the PSU. My transformer is out of its specifications yields 21.3V after bridge rectification. And 0.1A load (12V fan for cooling pass ...
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0answers
34 views

Why Webench power tool suggested using this Hot-Swap Controller (TPS2420) for my design?

I was trying to build dc to dc converter that has one input which is anywhere between 9V-20V and has 4 outputs: 5v @ 2.5A, 3.3V @ 2.5A, 3.3 @ 1.5A, and 1.5V @ 1.5A. So, I sequenced the outputs and ...
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1answer
32 views

Does a DC isolator smooth the voltage as well as a regulator?

I'm designing a power supply for multiple guitar pedals. To minimise noise I'd like the output voltage to be smooth when it's up and running. (I don't mind about small transient fluctuations when ...
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70 views

Diodes - minimum forward conduction current

I've been working on a GPS tracker which is intended to run/idle on a battery for an extended length of time (2+ years). The tracker uses an accelerometer (LIS3DH) and remains in a sleep state until ...
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1answer
50 views

Big voltage drop on output of voltage regulator on adding load

I have a voltage regulator that takes in 12V and outputs 5V. However whenever I add a load at the output, the voltage drops from 5V to 2.4V. This is not even a high current load and either way the ...
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71 views

Can AVss and GND be same for ADC

I've been working with an ADC which requires AVdd-AVss for the analogue part and Vcc-GND for the digital part. The power was supplied through regulators to get a clean voltage. In this schematic ...
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4answers
90 views

Voltage error when connecting a zener diode

I am working on a project where i need to measure the battery voltage and send the measurement to a uC, which is powered by 3.3V. The voltage divider is projected as shown before: As input we have ...
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3answers
85 views

Speed limiter - 24v Motors

I'm looking for a way to limit the speed of some wheelchair motors in order to gain better control when using them in my RC device. Currently the motors are very sharp and don't ramp up to speed, ...
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2answers
3k views

What is the role of the transistor and diode in a soft start circuit?

Please can someone explain the purpose of both the transistor and diode in this soft start circuit
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127 views

Is there a way to change AC 120 V @ 60 Hz to AC 120 V @ 40 Hz?

My grandfather has Alzheimer’s and I read in a science article that a sound or light “played” at 40 Hz interacts with the waves in your brain to break apart the plaque build-up and reduce memory loss. ...
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47 views

How to get output of 12V from a 15V output without dropping the current

I am planning on using NI myDaq to power a motor and encoder which requires 12V, but myDaq outputs 15V. How can I reduce the voltage to 12V without dropping the current? I was planning on using a ...
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2answers
64 views

MCP1703 quiescent current is very high

I want to use the MCP1703 regulator in battery powered projects. The datasheet of this regulator says that the quiescent current is typical 2 uA. I measured the quiescent current for the MCP1703-5 ...
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1answer
120 views

RT6224D-based step down circuit yields 0V - why?

We received a set of prototype boards. They have a DC power supply input feeding into a step-down converter, which is built around an RT6224D. It is supposed to deliver 5.0V. The circuit is almost ...
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0answers
40 views

Regulate ~350V spikes (duration nanoseconds) to logical level 5Volts

Use standard 5.1Volt zenerdiode? Can I trust that with zener diode it wont leak over 5 volts, concerning fast raising high voltage spikes. How about resistor sizing, the input goes to Arduino ...
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3answers
117 views

Can I use a 78S05 regulator in place of 78L05?

I'm trying to do this circuit : Can I use a 78S05 regulator instead of the 78L05? Or I need the 78L05 to realize this circuit. Best regards
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1answer
69 views

Resistor values on a 12v 10a circuit with LT3045 LDO

I am currently working on a project that aims to provide 12v 10a in the final output. I am quite new to EE and wasn't quite sure if I have choose the correct resistors value as highlighted in the ...
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1answer
44 views

Xbox one controller rechargeable battery

I wanna make rechargeable batteries for Xbox one controller.i'm new in this field So I have some questions 1_The controllers voltage input is 2.4-3.0 volt. Now is any issues if I use li_ion 14500 ...
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0answers
57 views

Smart undervoltage protection

what is the simplest way to regulate the min DC voltage in a circuit? ...
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1answer
58 views

buck converter with a simple bypass schematic mode?

in my design i need to place a buck converter 10-30V input with a fixed 12V output. my concern is that when the battery volatge level is low (for instance 10v) the device will stop bucking. so i want ...
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1answer
90 views

Why is this power supply split?

I am looking at a schematic for the Pixhawk 2 board. It has a complex power distribution system (see photo below) Much of the complexity exists for one of two reasons redundancy shutting off ...
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1answer
80 views

115 volts vs 240 volts [closed]

I am a novice and are working on a project . I need to get a view point of if im heading in the correct direction. My question is: Can I put two 115 volt 2 hp motors through a step down out of a 240 ...
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1answer
94 views

How much power does LM7805 dissipate?

I'm using an LM7805 in voltage regulator mode. Vin is 15V Vout is 5V (regulated) The attached load draws 200mA How to calculate how much power the LM7805 would dissipate in this setup (and whether ...
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2answers
73 views

electronic dc voltage regulator controlled by arduino

i am new to the electronic things so please help me figure out a solution. I am looking for a way to control voltage by Arduino of my 60volt 10 amp dc power supply i.e to get any voltage from 0 to 60 ...