# Questions tagged [voltage-divider]

A voltage divider is a circuit that produces an output voltage that is proportional to the input voltage. One typical configuration consists of a pair of resistors in series from the input voltage to ground, with the output voltage taken from the junction of the resistors. As an example: two equal-valued resistors will give an output voltage that is 50% of the input voltage.

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### Voltage Divider on Op Amp Feedback

I'm trying to understand the schematic of this Adafruit UV sensor: (Note: [U2] GUVA-S125D is a photodiode.) I understand the purpose of the other components, but haven't encountered a voltage divider ...
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### What is the expected maximum voltage for the pulse from this flow meter circuit?

I am trying to interface a flowmeter with a PLC. I would like to know the expected maximum amplitude for the pulse from this circuit if using 24V as the power supply. The input impedance at the PLC ...
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907 views

### How to choose correct resistor values when designing a circuit?

I have designed this voltage divider circuit. The idea was to ensure the 5V LED (L1) and the 3.3V LED (L2) receive the correct amount of current so that they do not burn up. So far I figure the ...
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### Designing battery voltage measurement with passive balancing

At work I have been busy designing a circuit for measuring the voltages of three batteries that are connected in series to each other. A microcontroller will read the voltages and determine which is ...
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1 vote
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I made a ADCs board (AD7194) and DACs board (AD5689). Each DAC (separated ground) could output 0-5V, and Each ADC channel could measure 0-3.3V. I used a voltage divider network to turn 0-5V to 0-3.3V. ...
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### LM5013 buck regulator won't have high duty cycles

I have made a PCB with the LM5013 buck regulator, but can't seem to get the output voltage high enough. The goal is to be able to adjust the output voltage using the LOAD_REGULATE pin, for a variable ...
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1 vote
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### What is the proper way to make a configurable split-supply voltage clamp with voltage dividers?

Being a beginner in electronics and not having had exposure to a lot of “best practices” I was trying to generalize the voltage clamp to arbitrary positive and negative clamping voltages. The ...
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### Switching voltage divider and low pass filter combined

I have an input signal which I want to switch from 12V-5V and a low pass filter directly after that, the issue is, if there wasn't a switch I can calculate the cut-off frequency easily. In my case, ...
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132 views

### Calculating current through a diode in a voltage divider circuit

I have a voltage divider circuit which I use to drive two LEDs with different luminous intensity. I understand that this is not the best way to do it but I wanted to control two LEDs with the same ...
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### Trimmer Potentiometer with Unexpected Voltage Range

I designed a voltage divider circuit using a trimmer potentiometer 3224J-1-103E for the first time. But, upon receiving the board, I found out that I was unable to tune the potentiometer across its ...
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### How to analyze and simplify a voltage divider with a second voltage source?

How do I simplify the circuit below? simulate this circuit – Schematic created using CircuitLab I know that R2 and R3 form a voltage divider, but I can't figure out the input impedance that In ...
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### Unknown use 20 V injection in KNX Digital input (read switch status) gvs 4fold

This is a circuit that I've recreated from gvs 4fold digital input. There is common and wire that goes to 4 switches (this circuit only shows 1 of them) when it it's closed the microcontroller reads ...
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### How to measure multiple resistances with Arduino Uno, without one measurement influencing the other?

I'm working on a project where I aim to measure resistances using an Arduino Uno. I started with two separate voltage dividers, each using a 1 MOhm reference resistor, connected to a common Arduino ...
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### Understanding Voltage Read in Voltage Divider for NXP S32K118 Microcontroller ADC

I am having a bit of a hard time understanding the voltage read in the voltage divider that is being an input for an ADC to an NXP microcontroller, S32K118. Below is the schematic of the circuit. ...
1 vote
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### More current draw from a power supply based on a voltage divider

I've built a circuit that needs a power supply that can provide -12V, 5V and 12V. I've built the circuit below as a proof of concept, being aware that I might need to build something that allows for ...
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### Beginner question regarding voltage divider for microcontroller

I am a beginner concerning electronics and would love to learn something new. I have a Teensy 4.1 and would like to calculate an encoder's speed. The encoder is built in into a system which supplies ...
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### How to connect 3V dc motor to 5V power source? [closed]

I can't get a grasp of electro-engineering basics Given a DC motor 3V and 5.12V power supply from a phone charger I thought I can use voltage divider to divide 5.12V into 3V and 2.12V, seems logical <...
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### Unusual but consistent variation in alternate sensor analog readings

I have designed some sensors that take readings of timber resistance between 2 screws with the idea to determine if the timber is getting wet from a leak. I have had a trial setup running with 6 ...
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### Role of a resistor in a specific, simple circuit

i am currently reading "make:electronics" from Charles Platt. On page 129 in Figure 3-87 i found a circuit, which i have reconstructed in the following image: The circuit is supposed to do ...
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### Why don't these resistors affect the gain in voltage divider bias?

Our textbook says that voltage gain is not affected by the R1 and R2 resistors, but I don't understand the reason behind it. Also, don't we get the 1/gm that is in the denominator from r(pi) resistor ...
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1 vote
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### Fast high-voltage diode stack (for snubber circuit)

I have a specific application in mind, but a more general question regarding diode stacks. System overview: We have a constant-current source which is driving a constant current through a magnet. We ...
1 vote
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### Driving 5 and 3.3 V square wave from a single terminal

I'm quite new to the topic and for fun I'm building a low frequency square wave generator with parts I currently have. Overall it works just fine while built on a breadboard, however I would like to ...
1 vote
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### Help me on this voltage divider question

There is only description of the circuit and a question. In a voltage divider circuit powered by a 12V source, two resistors R₁ and R₂ are connected in series. An LED with a forward voltage drop of ...
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### Voltage divider network 12V / 24V option to UVLO pin of LED driver

I have a voltage divider network with R1 and R2 and another R2 in parellel but not connected to ground. I have a dip switch where turning it on changes to 24V so it adds the second R2 to ground. Can ...
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87 views

I'm currently working on a hotplate project with an ESP32, utilizing a 10k ohm NTC thermistor (B57550G1103F000) capable of measuring temperatures up to 300°C. However, I'm encountering issues with ...
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### Superposition method to get the voltage

I want to know the voltage level at node E. Using superposition, I'm having a hard time calculating when 1 V and 2.5 mA go to 0. When 5 V meets 8 kΩ and 8 kΩ and 0.4 kΩ will be in parallel. I'm ...
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### Finding resistor values in a voltage divider circuit involving a zener diode

I want to use the TLC59212 latched driver. Recommended voltage supply is 4V min, 5.5V max. I understand that I can't use it on 3V. High level input is Vcc*0.7 Min. ...
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### How to control 0-5V in 5 steps? (1V, 2V, 3V, 4V and 5V) [closed]

I want to change a 10k potentiometer that is connected as a voltage divider to a 5V supply. So, instead of a potentiometer, I need a way to divide that 5V supply into 5V steps (1V, 2V, 3V, 4V and 5V) ...
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### Why is a variable resistor (R101) used in this circuit?

This is from a brake system plausibility device for a Formula Student race car. I'm confused why a variable resistor is used in this case and why couldn't there be a regular resistor instead like the ...
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### External Hysteresis Resistive Divider for MAX 6777

I want to switch on power to an ESP32, when a capacitor reaches 4.8V, and turn off the power, when 3.3V are reached. In this question: Use supercapacitor to power microcontroller I was asked to better ...
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### Voltage divider with filter cap gain derivation

I am a mechanical engineer by training and I'm self-studying circuits. I'm trying to understand how to derive the gain and cut-off frequency for the following circuit: I think that I should use the ...
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### operational amplifiers, voltage divider

Could someone please tell me what is the value of Ux? How can i calculate it? is Ux = (U1 - U2) * R2/(R1+R2) correct?
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### Pulling 5V logic low using 3.3V microcontroller

I have a shop-bought, small, portable dehumidifier that is controlled by a 5V logic chip internally. I'd like to be able to control it remotely using an ESP8266 or ESP32 (i.e. 3.3V logic). I only need ...
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### Parallel capacitor affecting voltage divider circuit

Ran into a bit of a strange issue with a voltage divider. I take the voltage of a single cell li-ion and divide it down to a 0 - 3V range so it can be read by an ESP32, I then multiply this voltage by ...
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### MP28167-A DC-DC converter recommends a resistor T-network in feedback loop

I am designing a DC-DC buck-boost converter using the MP28167-A, and the datasheet contains this section: I understand the need for a resistor divider such that the closed-loop control regulates the ...
309 views

### Sanity Check: Does adding a second voltage divider change the properties of the original?

I have a thermistor configured in a simple voltage divider on a 5V circuit as follows: I have no control over that part of the circuit. The problem is that, at normal operating temperatures, that ...
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1 vote
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### Could a voltage divider with more than two resistors be used?

As a step in an exercise, I'm trying to find voltages $V_1$ and $V_2$ below Could a voltage divider (with more than two resistors) be used here? So that, for example: V_2 = \frac{2\ \mathrm{k\...
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### Wheatstone bridge connected to op-amp: confusion about Vout formula

I am not sure when the correct formula for Vout is Vout = G(VA - VB) or Vout = -G(VA - VB). Can you explain the difference between these two examples? The circuits and the formulas provided are from ...
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### LDR and 2N2222A (beginner)

Learning electronic, I struggle understanding resistors values. I'm following a tutorial: Classic Circuits You Should Know: Light/Dark Detector. It uses a NPN 2N2222A as a switch to turn on/off a led, ...
160 views

### TB6600 / using with low voltage stepper motor

I'm using a classic TB6600 Stepper Motor driver (see for example link) I have a stepper motor that is rated for 5 VDC (datasheet). I have the datasheet, but it does not specify a current limit. I ...
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### Voltage follower generates voltage by itself [closed]

I am currently working on a project that requires me to measure a capacitor voltage that can reach up to 250 V. To measure such a high voltage I first created a voltage divider with very high resistor ...
52 views

### Low-pass filter with a load

how can be the voltage of a low-pass filter be mathematically described when a load is connected? Is it possible to ignore the effect of the load on its voltage as something like this circuit can be ...
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### Trying to build a wattmeter and register it with Arduino. Will it work?

In the last three months, my electricity bill consumption increasead by 50% with no known reason. I got hyper focused on discovering how to prevent that and how to control my energy consumption better....
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### Hysteresis on inverting terminal for comparator circuits?

If you examine 98% of circuits online that include hysteresis for a comparator, they always implement the hysteresis on the non-inverting input, like so: This is easy enough to calculate. However, ...
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### Voltage divider in op amp

I don’t understand how they calculated V+. I would appreciate an explanation.
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### Find Vs and the power supplied by the 10V source [duplicate]

I am stuck on this textbook problem where the chapter is about Kirchhoff's Laws (Ohms, KCL, KVL, Voltage Division, Current Division, Wye-Delta, and lastly Dependent Sources). The chapter does not ...
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### How do I take a 24 volt DC 10-30 kHz PWM signal from a Click Plus PLC and convert it to a 5 volt DC PWM signal to control a pump?

I am working on a small dose spraying system for a farming application. I have a Click Plus PLC, part number C2-01CPU-2, and it has one IO card so far, a C2-14D2. I want the PLC to control a Kamoer ...
1 vote
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### Divide the voltage output of a DC power supply

I'm a beginner in electronics and I am teaching myself the basics of schematics and electricity. I designed this simple circuit that allows to choose individually the voltage across 5 resistors and ...
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