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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61 views

Phase Shifter: why is simple RC circuit's output 0 when phase is 90 deg?

I am rereading an electronics book (Fundamentals of Electric Circuits; Alexander) that says that the circuits or have the total impedance Z = R + jXc and that the phase shift is given by ...
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3answers
103 views

A series resistor behind a reverse biased zener diode

simulate this circuit – Schematic created using CircuitLab If the Zener is rated at 4V, and the resistors R1 R2 are both 300ohm, may I know what is the value for Vout? I know this is a ...
0
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3answers
49 views

Capacitor on line with high frequency digital signal?

Capacitors act as a short for high frequency signals. If I place a capacitor on a digital 5V PWM line or perhaps a motor encoder line does the cap still act as a short to ground for the square wave ...
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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 ...
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2answers
25 views

Connecting RaspberryPi & Leonardo-voltage divider needed?

According to this article when connecting a RPi to a Uno a voltage divider is needed because of the voltage difference. Does the same apply to a RPi and Leonardo?
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2answers
119 views

What do you mean by -3db cut off frequency in low-pass-filters?

I have a low pass filter as follows. simulate this circuit – Schematic created using CircuitLab Using voltage divider I get $$\frac{V_{out}}{V_{in}} = \frac{1}{\sqrt{1+(\omega RC)^2}} ...
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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 ...
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0answers
35 views

Why Wouldn't The Resistance Of A “Continuous-Dynode” Electron Multiplier Operating In A Series Circuit Be Negative Or Zero?

I'm not sure whether this question has been asked before, (and I hope that my use of terminology is appropriate and clear). But why doesn't adding a "continuous-dynode" electron multiplier, as a ...
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2answers
77 views

Handling high voltage input range to comparator

I'm using 3 comparators for sensorless back EMF commutation of a BLDC motor. This involves comparing the voltage of each motor phase to a neutral point to detect zero crossings. See Microchip AN970 ...
0
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1answer
62 views

Measuring voltage output in a voltage divider

I'm currently working my way through Electronics for Dummies, where I am shown a simple voltage divider circuit consisting of a 9V battery and two resistors, R1 (12,000 ohm) and R2 (15,000 ohm). ...
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2answers
177 views

Ohm's Law for voltage divider

I'm currently working my way through electronics for dummies, where I am shown a simple voltage divider circuit comprising of a 6V battery and 2 resistors, R1 (220 ohm) and R2 (1000 ohm) in series. ...
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3answers
118 views

Generating various reference voltages in a circuit

How does one go about accurately setting reference voltages at various points in a given circuit (e.g. various threshold voltages). Obviously we can have a potential divider from the main power supply ...
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1answer
129 views

How to calculate voltage divider time constant?

A cheap and easy way of interfacing a 5V device with a 3.3V device is to use a simple voltage divider. I've read using a voltage divider to convert a fast-changing signal (such as serial lines) can ...
1
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1answer
72 views

Drop voltage for DC Brushed motor

Well, I have a little problem, I'm out of resources for the next month (read: funds for electronics) and I ordered a 12V accumulator/lead battery. The motors I have are rated for 7.4 Volts and are ...
1
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2answers
200 views

Is it safe to use a voltage divider for Arduino and DC motor controller?

I have ordered a Dual H-Bridge 12A continuous (30A peak) Polulu motor driver shield for my upcoming (first time ever, a 1.2m long tank made of wood) robot project. I was thinking about how to supply ...
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6answers
113 views

BJT Four resistor bias circuit analysis

I am currently studying BJTs but am having trouble analysing the four resistor bias circuit. My textbook gives the following circuit and says we can use voltage divider across R1 and R2 to find VB. ...
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3answers
106 views

How can I change a +/- 5V Sine Wave to a (0 to 5V) signal for an ADC

I've been digging into this for the past couple of days and I could really use some help. Here's the details: Input: Sine wave going from +5V to -5V Output(needs to be): 0V to +5V [0v when input is ...
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3answers
119 views

Calculate voltage, current and resistance in a complex mixed circuit

How can I calculate voltage and current on each resistor (especially R5) in this circuit? What is its overall resistance? I have no idea how to do this.
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3answers
75 views

Voltage divider with short circuit part 2

simulate this circuit – Schematic created using CircuitLab This question is a slightly modified follow-up to my previous question Voltage divider with a short, what is Vout? In this ...
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2answers
75 views

Voltage divider with a short, what is Vout?

Figure 1: A B Vin---====-----====--+--====-----GND R1 R2 | R3 | Vout In ...
2
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2answers
51 views

Flipping Output Logic

I have the following circuit: The diagram above has a pot between VCC, LM393 and Ground, on my board pictured below this is replaced by a voltage divider with two 10k pots. It looks like this: ...
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4answers
406 views

Voltage Divider DC 1000W for LED

I´ve done some research but not clear solutions are given to this problem, so I will post my case here in case somebody can help. Thanks in advance. I want to use a DC power supply to power up 121 ...
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5answers
109 views

Resistive loading effect voltage drop

I have been working on a project that is supplied by 8.4v battery. I then used the 7805 voltage regulator to get 5v and supply the electronics. Later, I figured out that I need to have 3.3v along ...
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1answer
73 views

Not enough current for voltage divider?

I'm trying to use a HIH4030 humidity sensor, where the output value is provided to a XBee. Considering that output sensor max output voltage is around 4V and the XBee ADC only supports 1,2V, I took ...
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3answers
100 views

What is a voltage divider and how does it works?

Ok so this is a voltage divider shown in my text-book There was not much detail about it and from what is given I can't get an idea of what it's purpose is and how it works, can anyone explain it ...
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1answer
52 views

How can I protect my SMPS feedback voltage divider from loading effects?

Background: I now have a working switched mode boost converter on a breadboard, working as a 12 Volt DC to 24 Volt DC converter. I was troubleshooting what looked like an output voltage problem when I ...
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4answers
207 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 ...
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3answers
152 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
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4answers
679 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
270 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
148 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
137 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
69 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 ...
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1answer
433 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 ...
1
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3answers
191 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
108 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
77 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
188 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
293 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
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1answer
452 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
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1answer
56 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
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2answers
234 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
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2answers
148 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
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1answer
54 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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2answers
76 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
103 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
315 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 ...
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2answers
156 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
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2answers
104 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
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2answers
210 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 ...