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 resisors in series from the input voltage to ground, with the output voltage taken from the junction of the resistors. As an example two equal ...

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4answers
101 views

Voltage divider for battery monitor ADC - loading effect?

I'm building a voltage divider to use for feeding into an ADC to determine the battery voltage of a device I'm designing. Is it important to consider the input impedance in the ADC and to account for ...
1
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3answers
87 views

Using single resistor to receive 5v signal on the 3.3v rated pin

I have been investigating ways to safely receive 5v signal on the input pin that can only support 3.3v input signal. I came across an article that states that it's possible to only use a single 10k ...
3
votes
4answers
381 views

When would I use a voltage regulator vs voltage divider?

When would you use a voltage regulator vs a resistor voltage divider? Are there any uses for which a resistor divider is particularly bad?
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1answer
142 views

Getting 9V and 400-500mA out of a 24V power supply

I recently bought this power supply to power a microstepping stepper motor controller (which requires an input voltage of 24V). My project requires the ability to dynamically turn on and off an ...
1
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3answers
130 views

How to uniquely identify which PCB is plugged in / connected

I am designing a board (Main PCB) into which any one of about 60 slightly different boards (Peripheral PCB) may be connected/plugged-in. The challenge I'm facing is to autonomously identify which of ...
0
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3answers
102 views

Voltage of Voltage Regulator changes when a Potential Divider is added

A Keithley 2400 Source meter is used to provide +7V. Using Fluke 179 Multimeter, the potential across the source meter leads is 7.00V. The source meter is then ...
0
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1answer
39 views

Universal Voltage Divider Bias Circuit with both BJT and JFET

I am dealing with the following circuit: I am trying to understand if I can just assume that, much like in the JFET voltage divider circuit, V_G = 10/(40+10) * 16V , or if the presence of the BJT ...
5
votes
1answer
149 views

Detect Arduino power failure and save data

Prologue On an Arduino Mega, I need to save data into the EEPROM (about 40 bytes) in case of power failure. The data is constantly changing (steppers position, speed, etc), but since the EEPROM has ...
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3answers
129 views

How do you set the reference voltage for a comparator?

I know this is certainly a beginner's question but am a first year student so hopefully I can be forgiven. I was looking through a electronics booklet provided by IKES website, and it's talking about ...
4
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2answers
73 views

Voltage Dividers

I've just started design in electronics and am a student of Electrical Engineering. The questions that I have are the following: How many resistors can be used for a voltage divider configuration? ...
1
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1answer
70 views

Effects of “loading down” Voltage-Divider Circuits

Hello I am currently a beginner in the world of electrical engineering and would like some help on voltage-divider circuits. My question mainly concerns the "loading down effect". Can someone please ...
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1answer
161 views

Voltage divider circuit and the Pull-down resister

I am reading pull-down resister here. PART-1 The circuit schematic of a light sensor using a voltage divider circuit is as shown: LDR has a resistance of 500\$ \Omega \$, 0.5k\$ \Omega \$ , in ...
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1answer
198 views

Problem testing an ADC with a DAC and voltage divider

I am testing a self-made ADC shield for Arduino Due based on the ADS1299, a 24-bit ADC with a 24x programmable gain amplifier. I have a signal generator sketch running on another Arduino Due that can ...
4
votes
1answer
368 views

Voltage divider using capacitors

A test circuit requires to generate 1V (50Hz, sine) using a voltage divider made of capacitors. Simulation of the circuit using two identical ceramics capacitors (±5%) gives half of the input voltage ...
0
votes
1answer
50 views

A voltage regulator that is controlling a voltage

My scenario is that I am having a circuit which having 12V as the input voltage and works beween 8V to 15V. I want to limit this circuit in a way that if the input voltage drops below 12V criuit ...
2
votes
2answers
134 views

Slew Rate Calculation

I’m in the process of selecting an op amp to act as a voltage follower for the input signal into my data acquisition card Im measuring all types of signals just like an oscilloscope would Do I have ...
1
vote
2answers
102 views

How does this power supply (resistor/capacitor) divider filter work? [duplicate]

I've been looking at various valve guitar amplifier circuits and in specific, the power supply section. I've been seeing a particular circuit that's repeating itself here and there in the power ...
1
vote
1answer
39 views

View High Voltage AC Signal on Oscilloscope

I would like to capture a high voltage AC signal on an oscilloscope. Input signal: 160V @ 400Hz Output signal: ~40V @ 400Hz Oscilloscope: TDS3014C I intend to use a voltage divider: 100k ohm (1/2 ...
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votes
2answers
66 views

Reduce voltage of an audio output [closed]

I have a hands-free car kit that uses a standard headphones socket to send output to the bundled speaker. I want to replace the speaker and connect the output to my car's radio AUX input. The output ...
1
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2answers
100 views

Take the voltage out of a voltage divider with no distortion

In the (simplified) schematics below, I would like to measure the voltage at point A with an instrument that I have to plug at point B. The problem is that if I simply add a wire between A and B, ...
3
votes
1answer
157 views

ATMEL Xmega ADC Input impedance

I need to read a 0-6V buffered analog signal from a sensor with the ATXMega256A3BU ADC. With an external voltage reference I can measure voltage level up to about 3V. I'm going to realize a voltage ...
1
vote
2answers
130 views

Understanding Ohm and Kirchhoff [closed]

I'm a computer programmer by trade who has taken an interest in Arduino with the hopes of eventually producing a particular hardware project that has captured my hobby/side-business interest. I ...
1
vote
2answers
93 views

Impedance to voltage range

I'm trying to get a voltage in a range from a potentiometer. The potentiometer theorically varies between 22k and 40k (R1 in the shematic) but I'm unsure as I currently don't have it in my hands. I ...
1
vote
2answers
131 views

Convert 10.5V to 15V into 0 - 3.3V range for adc input

I need to measure a voltage range of 10.5-15V to 0.025mv accuracy. This is a resolution of 180,000 - which is huge i know. The reason for this is because I will be measuring the voltage drop across a ...
1
vote
1answer
123 views

How to get input voltage of 5 and 6 volts

I have an interesting problem in building something with robotics. I am using a PIC16F877A micro-controller to control the robot. The motors of the robot require 6 volts and the PIC requires 5 ...
1
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2answers
101 views

What is the correct way to interface 3.3v logic with the PS_ON# 5v signal on a standard PC power Supply?

The PS_ON# line of a standard ATX PC power supply needs to be pulled to ground to turn the supply on. The signals on an ATX supply are 5v logic according to the standard. I'm trying to re-purpose an ...
2
votes
3answers
103 views

Combined ADC level shift/offset and scaling

I'm trying to sense the voltage from a 2 cell Li-ion battery that has a usable range from 2.5 to 4.4 Volts per cell (nominal 3.0 - 4.2 V). The ADC I have has a range from 0 - 1.8 V and is 12 bits. I ...
0
votes
1answer
70 views

burden resistor and/or voltage divider in an energy-sensing CT setup

I want to (eventually) build myself a home power monitor using basic current transformers. While reading on various circuit designs, I've stumbled upon what must be a very basic question. If we look ...
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votes
2answers
144 views

Wheastone Bridge vs. voltage divider [closed]

I read that Wheatstone bridge is more sensitive than voltage divider, since it acts as a DC offset removal circuit. But I can't understand why ?
1
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3answers
94 views

Is voltage divider output affected by load resistance?

Very basic question. Assume a voltage divider where both divider resistors are equal value, i.e. 100K. If 48v is the applied voltage, it's easy to see that we'll measure 24v across the "load ...
1
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1answer
70 views

transistor characteristics - Ube0 number meaning

i'm trying to guess meaning of value marked as Ube0 in datasheets. (datasheet adress: http://www.datasheetarchive.com/dlmain/Datasheets-36/DSA-700258.pdf, the transistor I want to use is Tesla ...
0
votes
0answers
56 views

RC Differentiators

I am reading a very welknown book "The Art of Electronics", and I got confused when it started talking about Differentators. Few sections eariler, it disribtes that how we would want to minimize ...
0
votes
2answers
226 views

Using Linear Voltage Regulators in Series?

I'm trying to design a power supply circuit that can output four voltages from the same circuit using linear voltage regulators. I'm still learning a lot of this, and trying to stick to the LM7800 ...
3
votes
3answers
219 views

What is the purpose of a voltage divider in a flex sensor?

I've been following this flex-sensor-arduino tutorial on setting up a simple flex sensor with Arduino, and I got confused on this part: The flex sensor changes its resistance when flexed so we can ...
0
votes
2answers
97 views

From 5v to 3.3v at from 8mA to 160mA

I'm working on an arduino project. The arduino have a 5V output up to 500mA and a 3.3V output up to 50mA. The problem is i have to power several circuits under 3.3V who consume between 8mA and 20mA ...
1
vote
2answers
71 views

Voltage divider but don't know current requirement, so how to pick the ratio

I want to connect my little RS232 to TTL converter to a 5V power supply but the converter needs 3v3. So I thought, even with my very little electronics knowledge, I could knock up a potential divider ...
3
votes
2answers
326 views

PIC - How to skirt around low maximum ADC input impedance?

Reading a 9V battery on a PIC is nothing new. The most simple and straightforward way is with a voltage divider. I'd like to keep the divider resistances cranked up into the hundreds of kohms so I'm ...
1
vote
2answers
62 views

low resistance material used for sensing

I'm researching conductive fabric with a surface resistivity <0.5Ω/m2 (unstretched). I've used a voltage divider setup to connect with an ADC pin of microcontroller (ATMega/Arduino board). ...
0
votes
0answers
87 views

Voltage divider circuit pnp transistor

From the above circuit I wanted to know If the switch is in position 2, will the 100kΩ resistor be parallelt to the resistor R? Is the power dissipated by the transistor equal to Vce*IC
1
vote
1answer
96 views

TMP36 reading not steady if circuit has more elements

I have a TMP36 connected to an analog pin of an Atmega328p-pu on a breadboard (with Arduino bootloader), everything is powered w/+5V from an Arduino Uno R3 (which is used as a programmer). The ...
0
votes
1answer
91 views

Constant Sum Voltage Divider With Thermistor/Temp Sensor

I need a circuit with a thermistor/temp sensor that will essentially emulate a pot. In other words, I need a voltage divider that varies with the resistance of the thermistor/sensor, but keeps the ...
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votes
1answer
57 views

How would i go about finding Rl when rl is r3

How would i go about finding Rl :/ I'm so lost iv looked for examples and all they have done is confuse me
0
votes
1answer
511 views

Measure 0-10V using Arduino

A thermocouple amplifier outputs a voltage range of 1.2V to 8.8V for the temperature range -260C till 1380C when using a K-type ...
10
votes
3answers
401 views

Why should we need DAC ICs?

Please look at the schematic below. This is a very simple resistive adder that works fine with any standard ! (TTL,CMOS,...) or any arbitrary voltage that is fed into it. On the other hand as there is ...
0
votes
4answers
93 views

Schottky diodes for voltage conversion

I recently bought a DE0 FPGA board with GPIO headers. The schematics shows that some of them are protected with BAT54S Schottky diodes. Does it mean that if I input 5v logic level they will be ...
2
votes
1answer
78 views

How to voltage divide down a single ended analog signal? [duplicate]

I have a 0-5V Single ended analog signal coming into an A/D pin on my microcontroller. The Micro pin can tolerate only 0-3.3V analog signal. What can I do? Can I just add a simple voltage divider ...
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vote
1answer
92 views

Run a 5VDC 0.2A fan from a 24VDC 3.75A power supply - Help Needed

I am working on a project that is using a 24VDC 3.75A power supply and would like to have a small fan (5V 0.2A) to cool the amplifier and switching circuits within an enclosure. Could someone help ...
2
votes
1answer
63 views

How do I simplify this circuit to find resistor voltage?

In my circuits class, I am presented with the following exercise. simulate this circuit – Schematic created using CircuitLab The problem is to find the voltage across resistors A and B. ...
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votes
1answer
125 views

How do I provide 7 volts from a 12 volt source?

I want to power a GHI Panda II single board computer that has a GHI FEZ Connect shield attached for Ethernet access. GHI Documentation specifies 6.5 V to 7.5 V input for the Panda and shield that can ...
-6
votes
4answers
196 views

What are the advantages of using a voltage divider?

If you had a circuit hooked up like this: simulate this circuit – Schematic created using CircuitLab it would be using a voltage divider, as Vin(R2/(R1+R2)) is the voltage divider rule. ...