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
30 views

How can I rearrange the voltage divider formula for R2?

Can I please have a step by step explanation as to how I can rearrange the voltage divider formula to find R2. I dont understand how I end up with R2 = R1 x Vout/Vin - Vout.
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2answers
102 views

Sensing AC high voltage to microcontroller

I'd like to sense if I have AC 220V 50HZ available, and convert it to some logical level. I made such circuit, will it work? I use C1 as a resistor. Any recommendations what can be improved? ...
0
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2answers
66 views

Converting Voltage [duplicate]

I have a pair of batteries that can operate at 7.2V (series) or 3.6V (parallel) and I need to power up a device using 5V. I can use a Voltage Regulator to down voltage at 5V or I can use maybe ...
1
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1answer
41 views

Enable pin with maximum 3.0v

I've an Enable pin active-high that have maximum voltage rating of 3.0v, but I use a 3.3v MCU outputs. I've also a 3.0v voltage regulator on board. Should I use resistor voltage divider or there is a ...
0
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2answers
108 views

Voltage regulator from 24v to 3.7v [duplicate]

I need to build a simple voltage regulator that can drop voltage from 24V(from a DC power supply) to 3.7V and supply at least 2A or more(up to 5A if possibile). Can I just use a 2 resistor voltage ...
0
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2answers
46 views

using the Arduino internal reference 1.1v

So i want to measure a resistor of around 20 ohm in a voltage divider with an Arduino UNO R3. Is there any way on an arduino to use 1.1v instead of 5v? I want to do this to decrease the current, ...
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3answers
98 views

50 ohm terminator — voltage divider?

OK, obviously I'm misunderstanding something. I have a RedPitaya, which is an oscope+generator. Its output impedance is 50 ohms. If I send a signal from its output to its input (which is 1Mohm) ...
1
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3answers
205 views

Transform a 0-10V into 0-5V and use op-amps as buffers?

I would like to transform a 0-10V into a 0-5V so I can read it with "5V MCU" (like the AVR/Arduinos). In the most basic case I would just put 2 resistors and do a divider, but since I don't know how ...
0
votes
1answer
60 views

Capacitors Not Charging Uniformly

I have 2 identical PowerStor Series XB supercaps connected in series. Voltage rating of each is 2.5V. In series their capacitance is cut in half but the voltage drop over both of them should be ...
1
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1answer
42 views

TDA 2030 emmiting voltage to Line in

i've build 15w amp from TDA 2030 but currently i measure from input line to ground (measure are performed from audio jack), reaching 400 mV, my question is: -is that normal? how i can remove it? even ...
2
votes
3answers
316 views

Next level of resistor divider

I know how to calculate proportions of resistor values in resistor divider, but dont know how to jump into "next level" and calculate the precise values of resistors from proportion : For example to ...
2
votes
2answers
178 views

Transfer function of an op amp circuit

Let's suppose the following circuit: I am trying to find a relation between Vs, V1 and V2 at this circuit. Please note that Vs is measured in relation to the ground. I have declared some extra ...
0
votes
1answer
105 views

How much resistance will I need to drop the voltage?

9 Volts is applied to circuit. There is an LED which runs on 3 Volts. I want to drop 6 Volts. how much resistance (\$R_1\$) would I need for that?
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votes
1answer
69 views

How can I boost/limit a signal to TTL levels?

I am researching a data acquisition system to measure the amplitude and frequency of a 4,100Hz 5v-25v AC square wave signal. Actually this is version 2 for me, in the previous version I analyzed the ...
3
votes
1answer
200 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
344 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
168 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
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1answer
114 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
116 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
42 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
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2answers
60 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
60 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
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3answers
164 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
47 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
66 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
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1answer
57 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
150 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
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1answer
60 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
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1answer
101 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
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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
49 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
54 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
79 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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1answer
51 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
550 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
81 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
103 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
76 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 + ...
1
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0answers
184 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
73 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
116 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
50 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
39 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
124 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
85 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
194 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 ...
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vote
2answers
446 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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votes
3answers
96 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
336 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
129 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 ...