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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85 views

Resistors in series or one after?

I want to use a Voltage divider and i need to divide 5v to ~3.3 so I ordered 10K resistors on eBay, but the voltage divider needs a 20K and a 10K, can i use 2 10K's parralel as a 20K
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2answers
50 views

Voltage Dividers in a pull-up resistor circuit (why does the pin go to low)

I understand that when the button is in its open state the voltage on the input pin should be fairly close to \$ V_{cc} \$ provided \$ R_1 << R_2 \$ as \$ V_{in} = V_{cc} \frac{R_2}{R_1 + ...
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1answer
68 views

Thevenin equivalent over voltage divider

If R2 is a load, by removing it I obtain a thevenin equivalent circuit of 9V and R1 over terminals BC, so when I apply R2 over terminals BC, is the voltage across R2 9V? I know it's exactly the ...
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1answer
36 views

Single Phase Energy Meter using Atmega32

Version 1 : We are trying to measure the input voltage from the AC mains (which theoretically should be 230 V). The circuit to measure this is a simple resistor divider network as shown below. The ...
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1answer
99 views

Tuning LED circuit so LED turns on at specific voltage

I am attempting to add a signal activity LED to my dummy load box. I have constructed the following circuit and so far it does what it is supposed to (lights an LED with signal applied and does not ...
2
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1answer
37 views

Trimmer pot to fixed resistor conversion

Sorry for the simplicity of this question but I've been struggling on this circuit for a while. In the schematic link below you'll see a trimmer pot and I simply want to replace it with one/two fixed ...
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0answers
25 views

Need help finding Vo with changing frequences through the Voltage divider BJT

Help finding Vo with the changing values of frequency. R1 = 11.45k Ohms R2 = 4.4k Ohms Rc = 900 Ohms Re = 324.95K Ohms C1 = 10uF C2 = 10uF C3 = 50uF Vcc = 9V ...
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2answers
86 views

RC Integrator circuit final voltage

Given this integrator circuit: And with Vin being a pulse wave which changes alternatively from 0V to 5V with a frequence of 100KHz, I need to find out the value of Vout after a large number of ...
2
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1answer
66 views

Voltage Divider w/ Varying Load Current

I have an easy question that I feel I might be overlooking. The question I was given was: A 15V power supply is used to power a 6V, 500mA device. The device draws 500mA at the rated voltage, but ...
1
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1answer
102 views

Writing to SD Card cheaply

So, here's the scenario: I have an Arduino and an SD card. Unfortunately, I don't have one of the fancy shields, and I don't have the time to order one. As we know, Arduinos run on 5V, and SD cards ...
1
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2answers
80 views

Arduino clamp ammeter

I am using an Arduino Uno as a watch dog for a project I a doing; its job is to monitor what is happening in the system and shut down the system if it is not operating within spec. One of the ...
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3answers
79 views

How to reduce maximum power rating of dishwasher for use with photovoltaics inverter? [closed]

I have a photovoltaic power system and an inverter with an overall power rating of 1500 Watts. I want to connect a dishwasher which consumes 2200 Watts when heating the water. Question: What is the ...
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1answer
105 views

Solar power monitoring with Raspberry Pi

I want to measure the current and voltage from a set of small solar panels (about 10V and 100mA but not settled yet) using a Raspberry Pi. There will be between 4 and 6 panels. This project will ...
0
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4answers
106 views

Can a 5V regulator connect directly to a voltage divider to obtain a 2V output?

In my circuit, a lm78l05 is used to provide +5V voltage to other parts. And now I need another +2V source to shift my input signal from +-2V to 0~4V as the ADC ad7682 limits the input signal range ...
1
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1answer
35 views

Analyzing/designing positive feedback amplifier

I've been searching all around to find a tutorial on analyzing/designing a positive feedback amplifier, especially a single transistor in common collector mode, but with no luck... So, lets say I ...
4
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5answers
387 views

Stiff Voltage Divider Bias for an Emitter Follower

Below is an ac-coupled emitter follower with base bias provided by a voltage divider. I'm having a slight issue with how the resistor values are chosen for the biasing in the design example provided ...
2
votes
3answers
158 views

Low power serial bluetooth module with Arduino

I plan to use the HC-06 serial bluetooth module with an Arduino Leonardo. To my knowledge, the Arduino's serial pins output at 5V with 40mA of current. The HC-06's datasheet says it will accept input ...
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2answers
56 views

Resistor Magnitudes in Voltage Dividers

I recently made a voltage divider that uses a 10 ohm (top) and ~90 ohm (bottom) to divide a source voltage of 5v to 4.5v. The resistor values I used was somewhat arbitrary, in that I just picked a ...
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2answers
84 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
223 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 ...
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3answers
88 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
72 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
60 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
167 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
94 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
42 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 ...
0
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2answers
100 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
70 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
196 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. ...
1
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3answers
141 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 ...
2
votes
1answer
219 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
97 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
328 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 ...
0
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6answers
256 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. ...
0
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3answers
133 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 ...
1
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3answers
311 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
97 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
86 views

Voltage divider with a short, what is Vout?

Figure 1: A B Vin---====-----====--+--====-----GND R1 R2 | R3 | Vout In ...
2
votes
2answers
52 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: ...
3
votes
4answers
428 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 ...
1
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5answers
136 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 ...
0
votes
1answer
91 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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votes
3answers
118 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 ...
0
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1answer
77 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 ...
2
votes
4answers
313 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
510 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
1k 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?
1
vote
1answer
436 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
vote
3answers
154 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
156 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 ...