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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1answer
160 views

Is interfacing the 5V TTL UART with 3.3V microcontroller via voltage divider possible?

I need to connect my MSP430 microcontroller (3.3V) to interact with a 5V TTL UART camera ...
4
votes
4answers
272 views

Circuit for a coarse and fine setting potentiometer?

I've tried to find a circuit for a coarse and fine adjustment (two potentiometers) voltage divider, but I don't understand it and/or they don't have a linear response. Problem: I want to have an ...
1
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4answers
122 views

Sensing analog voltage on Arduino without loading the input circuit

I want to design a voltage divider for my Arduino Analog input pin, to be able to sense the change in voltage in a 9V, 250mA circuit (without loading it). Ive programmed the Arduino so that as soon ...
1
vote
1answer
88 views

Colpitts oscilator - purpose of voltage divider

I'm confused by the Colpitts oscillator shown below: I've marked my understanding of the various components, but I'm having trouble understanding the tank circuit. My understanding is that C1 and ...
1
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1answer
87 views

Scaling 12V PWM signal to 0-10V

I'm trying to translate a 3.3v PWM signal through an optocoupler to the 12V side of a circuit, filter it to obtain a relatively clear DC voltage, and scale that to 0-10V for a control element. So ...
0
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2answers
41 views

Arduino AnalogIn minimum current?

I've got a 12V source which I want to measure the voltage (or basically, just to check it's there) so have a voltage divider. Currently, with a 10k and 3k resistor, that brings it down to 2.77V and ...
0
votes
2answers
53 views

instrumentation of V-divider dual-thermistor circuit

here's the circuit - voltage divider with 2 matched thermistors ("matched" means close enough that the measured temperatures when thermistors are right next to each other comes close enough for my ...
0
votes
1answer
54 views

DC voltage stepping down but keeping current uchanged with no regulator [closed]

Is there any way to divide DC voltage or stepping it down but keeping the current peak unchanged? But I can't use a voltage regulator. In fact, I want to make a regulator 5V output into 4.5 ~ 4.7 V ...
2
votes
3answers
147 views

Questions on Operational Amplifiers

What I've learned so far from Navy school is that operational amplifiers are used as a substitute for transistor amplifiers and they contain three main circuits: the differential amplifier, common ...
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1answer
38 views

How to connect a jack lead to the input of a 741 circuit

Below is a diagram of a 741 circuit with a microphone attached, I've built the circuit and it works reasonably well. However is it possible to connect a jack lead to the circuit instead of a ...
1
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2answers
57 views

What is the best practice to generate positive and negative voltages to power an OpAmp [duplicate]

I would like to supply +4.5V & -4.5V to OpAmp using a 9V battery. I have tried using voltage divider which works. Please suggest if this is the best practice, are there any better ways of doing ...
0
votes
1answer
56 views

Feeding arduino with AC?

Im having trouble trying to understqnd this circuit , as you can see from http://www.instructables.com/id/Arduino-Audio-Input/?ALLSTEPS its a circuit that will amplify a signal from 200mV to 2.5V and ...
2
votes
2answers
134 views

Determine input resistance of a DMM using a voltage follower

In my electronics lab we constructed a voltage divider that consisted of two \$1\$M\$\Omega\$ resistors and measured the voltage drop between the two resistors and ground. We supplied \$15\$V and ...
0
votes
1answer
47 views

Current Sensing with ACS712 on Beaglebone Black

I am planning to use my BBB to perform some current sensing and was wanting to use the ACS712 chip. The chip operates off of 5V, but the analog inputs of the BBB have a max of 1.8V. How can I wire ...
0
votes
1answer
99 views

Can a simple voltage divider circuit be used to accurately measure voltage?

I have a discharger circuit that I intend to hook up to a 3V battery. Total resistance of the circuit (depending on how fast I intend to discharge it) will vary from 0.04 to 0.01 Ohms (that's 75A and ...
0
votes
2answers
101 views

Regarding the design of a basic voltage divider

I've just entered the fabulous world of circuitry and was wondering about the design of voltage dividers. I understand their function and formula quit well, but was wondering about the actual ...
0
votes
1answer
45 views

Downshifting binary signal from higher to lower voltage using an LM339 comparator

I'm working on an experiment where I'd like to shift a 24V on/off signal down to 3.5V or 5V (i.e. suitable to use with an Arduino or Raspberry Pi). For simplicity and safety - I really don't want to ...
0
votes
1answer
37 views

XBee (S2) Voltage Divider to Read Input 12v Alarm Output Pins

I have an XBee Series 2 and I was trying to detect an input from a signal which was 12v, so I used a voltage divider with R1=220k and R2=24k, I checked the output voltage with multipmeter and it was ...
0
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5answers
77 views

For a voltage divider circuit, why does \$V_{out} = I \times Z_{2}\$?

For a voltage divider circuit, why does Vout = I*Z2 ? I understand that Ohm's Law says V = I * R, but I am new to electronics. Can you explain this better? Why is Vout not I*Z1?
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votes
1answer
49 views

Voltage divider VS Voltage translator [duplicate]

I am building a PCB with some ICs. To sum up, I have a global 3.6V supply and I need to have an 1.8V reference for some IOs. I know the right way to do it is to use a voltage translator circuit ...
8
votes
1answer
538 views

Do serially connected diodes share equal reverse current?

If I place three cheap 200 V rated diodes across a 500 V supply instead of one expensive diode, is the system guarantied to work correctly? My worry is the situation at which two of the diodes share ...
1
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0answers
70 views

Building a +/- 150V DC power supply

I'm trying to build a +/- 150V battery powered DC power supply variable power supply. I have two of these 150V nixie power supplies: http://desmith.net/NMdS/Electronics/NixiePSU.html And was ...
0
votes
3answers
102 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
0
votes
2answers
67 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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0answers
149 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 ...
0
votes
1answer
57 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 ...
0
votes
1answer
111 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
votes
1answer
44 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 ...
0
votes
0answers
35 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 ...
0
votes
2answers
114 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
votes
1answer
82 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 ...
2
votes
2answers
167 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
vote
2answers
313 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 ...
-2
votes
3answers
89 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 ...
2
votes
2answers
292 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
votes
4answers
119 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
vote
1answer
43 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
votes
5answers
580 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
460 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 ...
0
votes
2answers
70 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 ...
1
vote
2answers
115 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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votes
3answers
373 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
votes
3answers
98 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 ...
0
votes
0answers
92 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 ...
1
vote
2answers
82 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?
1
vote
2answers
257 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}} ...
0
votes
1answer
96 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 ...
0
votes
0answers
49 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
votes
2answers
113 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
votes
1answer
87 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). ...