11
votes
Op Amp Feedback Resistors
To a first-order approximation, it's a matter of how much current the op-amp can provide (sets a lower bound on resistance), how much power you can stand to consume (sets a lower bound) how much error ...
- 36.3k
10
votes
Accepted
If more collisions happen with more resistance, why less heat is generated?
It is useful to draw an analogy between electric current and wind. At standard temperature and pressure, molecules in the air are traveling in random directions at very high velocities (in the range ...
- 26.1k
6
votes
Op Amp Feedback Resistors
There are a few considerations.
Frequency- at high frequency various capacitances have an effect so you don't generally want to be using MΩ resistors at high frequencies. It could cause poor behavior ...
3
votes
Resistance between any two points
\$R_{BF}\$ is shorted directly, so the calculation is pretty easy.
Redraw the circuit and you'll see that the answer for \$R_{CD}\$ has to be
$$R_{CD} = R2 \parallel (R3 + R4 \parallel R5)$$
You can ...
2
votes
Accepted
Generator With Adjustable Resistance
As you say, when you PWM a brushed DC permanent magnet motor, usually the motor has enough inductance so that you can dispense with any further filtering components and just use the switch. You can ...
- 171k
2
votes
Resistance vs Capacity in Building a Power Bank
In principle, you want the currents between paralleled cells to be matched, so you want matched resistance across each parallel section.
In principle, you want each series block to have the same ...
- 171k
1
vote
Op Amp Feedback Resistors
Introduction
Both non-inverting and inverting op-amp amplifiers use the same voltage divider as a feedback network; only in the former, it is an ordinary 1-input device while in the latter, it is a 2-...
- 18.2k
1
vote
Activating a circuit with a change in resistance
If the no-object-present resistance of the sensor is known, the sensor can be employed as a member of a resistor potential divider, whose output potential varies as the sensor resistance varies. Let's ...
- 42.1k
1
vote
How do I calculate total resistance?
\$R_1\$ is neither parallel nor in series with \$ R_2||R_3 \$. You have to apply KCL and KVL to find the resistance seen by E or J current sources. If there is no current source J and the branch is ...
- 855
1
vote
Need Help- Burglar Alarm System
For driving simple loads, both of those transistor can be used. And it causes no change to the resistor.
- 164k
1
vote
Resistance between any two points
It might help to redraw the circuit to better represent the series and parallel combinations of resistances found between C and D:
simulate this circuit – Schematic created using CircuitLab
...
- 42.1k
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