Questions tagged [voltage-divider]
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 resistors in series from the input voltage to ground, with the output voltage taken from the junction of the resistors. As an example: two equal-valued resistors will give an output voltage that is 50% of the input voltage.
1,437 questions
3 votes
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Why does a voltage divider work even with extreme resistor values?
I’m having trouble understanding voltage dividers. According to the standard formula: $$ V_{out} = V_{in} \cdot \frac{R_2}{R_1 + R_2} $$ If the two resistors, \$R_{1} = R_{2}\$, are equal in value ...
4 votes
2 answers
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Is optocoupler bias resistor and shunt regulator reference resistor value sufficient?
I am building one power supply and this is the circuit diagram of the isolation part. my question is : Is the value of the resistor that connected to the anode to the optocoupler(R18) and bias ...
6 votes
5 answers
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Is it common practice to add a capacitor to a voltage divider?
I came across a circuit module that uses a voltage divider to measure the value of a resistive sensor. However, unlike a simple divider made of two resistors, this one also includes a capacitor ...
2 votes
2 answers
746 views
Will the top cap be okay with a 75 V rating if the supply is 96 V?
My colleague and I are debating whether this is safe or best practice. Due to size constraints, the 10 µF could only be 75 V rated. The supply is 96 V. To me it looks like the 96 V could be killing ...
4 votes
2 answers
175 views
NMOS and PMOS in a series with VDD as voltage source, what will be the voltage between them?
I have an argument with a friend regarding the voltage between N and P and the voltage at OUT. I say that for A = '1' and B = '0': If Kn > Kp, so the voltage between the NMOS and PMOS is Vdd-Vtn ...
2 votes
2 answers
193 views
Diode voltage divider problem
For the voltage divider below, I am asked to find the Q-Point for both ideal diodes in forward-bias mode (i.e., they are both short circuits with one-way current): In my work, I found \$i_1\$ and \$...
3 votes
1 answer
330 views
Why is there a voltage divider on the input to these 8T28 chips?
The circuit diagram below is a section of a schematic for a Compukit UK101 Computer, made in 1979. I'm restoring one, (Was my first ever computer) and building a memory expansion / FDC for it. You can ...
0 votes
2 answers
162 views
Is there really any safety concern (beyond the obvious), regarding putting 240vac mains into a basic potential divider that is 210k Ohms?
I have been perplexed recently with regards to people on a forum, stating that it is unsafe to put 240vac directly into a basic potential divider. The divider was literally 210k ohms, with 3 resistors....
5 votes
3 answers
464 views
Is the non-inverting input pin of my op-amp drawing significant current from my circuit?
I am trying to make a simple Schmitt trigger circuit with the TLV9302. Input voltage is 5V. On the non-inverting input, I have a voltage divider from the 5V supply using two 10k resistors, with a 1M ...
1 vote
1 answer
101 views
How to Interface Multiple Voltage-Level Sensors (5V/12V) Using One Input Circuit?
I need to design a device that can compensate any VSS (Vehicle Speed sensor) from 5V to 24V or higher voltages as well. Like I need a universal circuit design that can work for any voltage levels. I ...
2 votes
2 answers
311 views
Voltage divider for ADS1115 input, auto circuit application
I want to measure how full my car's gas tank is using a raspberry pi. To do this, I am splicing into the fuel pump sender signal ('B' in the diagram below), which applies a resistance between 0 (gas ...
0 votes
1 answer
104 views
How to interpolate three points using a circuit?
Interpolating two points to create a circuit which will do what you want is easy, Suppose we have a input voltage Vin and a variable resistor and we want when the resistance of the variable resistor ...
3 votes
4 answers
350 views
How to derive the output voltage expression for an op-amp circuit with a DC offset at the non-inverting input?
I'm analyzing the following op-amp circuit: A sinusoidal voltage source connected through resistor \$R_1\$ to the inverting input. A feedback resistor \$R_f\$ from the output to the inverting input. A ...
3 votes
4 answers
403 views
How to calculate the upper limit for resistance of a voltage divider to feed an ADC?
I'm designing a battery powered device with constrained power consumption in orders of nano-amperes and micro-amperes. The microcontroller in use is a MSPM0L1304 connected through a very low Iq ...
0 votes
0 answers
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Enable on negative voltage protection circuit
I have a circuit that uses the TPS2394 IC for -15V protection, and it seems that I've ran into a timing issue. I need +15V to be present before the TPS2394 enables the -15V output. The IC doesn't have ...