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Consider the scenario without a heatsink first: -
The junction-to-ambient thermal resistance for the IRLZ44N is 62°C/watt
The on-resistance of the IRLZ44N is 0.022 Ω with a 10 volt gate-source drive voltage.
This means that if each is taking 10 amps drain current, the power dissipated is 2.2 watts in each. From that power we can conclude that the MOSFET ...
4
Visualization
Here is a picture with visualized currents and voltage(s) that can help understanding.
Current paths are represented by closed thick lines (loops) in green whose thickness is proportional to the current magnitude. Voltage drops are represented by vertical lines (bars) in red whose height is proportional to the voltage value. They are the same ...
3
About capacitors the formula Ic = C*dV/dt refers to the displacement current or to the current which charges/discharges the capacitor?
The displacement current through the capacitor, and the current which charges/discharges the plates have equal magnitude (at every instant).
3
Just rearrange it a bit and it will be a lot easier:
All this stuff is wired in parallel, and with zero-resistance perfect ideal wires (which exist only in theory) so it is possible to put them in any order you like without actually changing anything besides readability.
With real copper wires there would be a small voltage drop along the way, so this is of ...
2
In general, you can run this at 37V input and 380mA. This would still comply with the absolute maximum ratings where neither a maximum current nor maximum power dissipation are specified directly.
But: as you might have seen, this device has some protection features, like short circuit and overtemperature protection. Those implicitly limit both the current (&...
2
How much current it can pass is one property, and how much it can heat up by the power dissipated is another property.
You can input 5V and make 380mA 3.3V, and the regulator would heat up only at 0.65W, which is certainly doable.
If you input 37V, and output output 3.3V at 380mA, the poor chip has to dissipate 12.8W, which is completely absurd amount of ...
2
Could you please explain to me where I was not consistent?
Redraw your schematics
First off, already redraw the schematic using rules I'll add as an addendum below:
simulate this circuit – Schematic created using CircuitLab
Note that you can choose to make any node you want to, ground. Here, looking at your schematic all I did was to swap the series ...
2
When we say that the choice of the current direction does not matter it doesn't mean that we apply equations without taking into consideration the chosen directions.
After chosing the current directions we will get values for these currents. If the value is negative it means that the current direction is opposite to the chosen one.
Your error is simply in ...
2
The current in the input capacitor depends on the switching cell structure and the operating conditions. The first thing to realize with a perfect decoupling or with a front-end filter is that all the high-frequency ac pulses are delivered by the capacitor while the dc current flows in the input source. It is an approximation of course but this is what is ...
2
You won't get far with intuitions like "Will V1 not overpower V2". You should approach such problems with rigorous equations.
First, you should find all "nodes", these are parts that are connected with ideal wires (lines) and thus have the same potential (voltage). In this case, there are three nodes: the bottom part; top-left between V1 ...
2
I would like to protect an OpAmp power supply from overcurrent.
Basically, you can't, because the current drawn by the opamp depends on the load on its output.
It's a high voltage opamp, +/-30V, so if you use a 2kOhm load, and the output is near +30V it will output 15mA into the load. If the output is shorted to ground, it will output about 25mA. Since you ...
2
Voltage and current are emergent approximations, not fundamental things. If you want to bring the velocities of electrons into consideration, then you have to understand what's going on at the quantum mechanical level. Which is hard work.
Working with I and V requires ignoring the electron behaviour, just as working with pressure, which is also an emergent ...
1
In addition to the other answers, I would like to add that there are two different kinds of inductance.
is the usual inductance that describes the energy stored in the magnetic field.
is the kinetic inductance. This happens whenever the mean free path of electrons becomes appreciable, e.g. when transversing vacuum, in superconductors or some other ...
1
Yes, your thinking of both series and parallel circuits are correct.
The total supply voltage of 6V is correct for 6V worth of 1.5V lamps in series, and total supply of 1.5V is correct for 1.5V lamps in parallel.
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Before embarking in a 4mA current protection, what would be the damage of such a fault? would your power supply break?
It's interesting that you want to protect your supply, but you usually consider what your supply can give, not what is required in the standard situation (unless you are doing some kind of overload protection, like for motor). So more than ...
1
The rule that conventional current is always along the potential gradient applies only to purely resistive components. Capacitors can have current in both direction regardless of the instantaneous DC voltage.
While the current through a resistor a proportial to its voltage, the current through a cap is not proportial to its voltage, but instead to its dV/dt.
...
1
Load switch TPS272C45 by Texas Instruments outputs the current drawn by the load.
https://www.ti.com/lit/ds/symlink/tps272c45.pdf?ts=1618175801421
SNS is an analog output pin that outputs the analog output current drawn by the load.
Connect a resistor between SNS and GND.
This a selection filter at Texas Instruments in case you want to browse other load ...
1
But why do some devices have a current limit and some a power limit?
The current limit will be determined by the maximum allowable current density in the bonding wires and internal components of the chip. As current density increases so will heating and there has to be a physical limit to that.
The power limit will also be due to thermal considerations but ...
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