Questions tagged [current]
Flow of electric charge - typically movement of charge carriers, such as electrons. Measured in amperes (A).
6,673 questions
0
votes
1
answer
25
views
GPIO current requirements for 64×595 chips being driven with an ESP32? Do I need IO Extension chips?
I have a PCB I'm working on using SN74AHC595 8-bit registers. Specsheet
I have 64 of these chips connected in series (a 512 bit register). 4 inputs per chip to manage (So, each corresponding GPIO pin ...
- 133
6
votes
3
answers
426
views
Supply power, supply current, and amplifier dissipation regarding amplifiers
I'm in the early weeks of my Electronics 1 course and unfortunately my textbook is giving me more questions than answers. Here is the problem that has me most confused at the moment:
“An amplifier ...
- 79
-2
votes
4
answers
106
views
Does delta V*I represent the power that is "used up" by a portion of the circuit, or is it the power transferred by it onwards?
If one computes the direction of the energy flux into a circuit using the Poynting vector, one finds that it points into the surface of the wire from outside the wire. In this view, it seems natural ...
- 97
0
votes
4
answers
202
views
My understanding of BJT in saturation is broken
Let me start by describing what I already know about BJT operation. Pl correct me if I am wrong.
Suppose there is a NPN transistor.
Construction of BJT:
A NPN transistor is made up of 02 ...
- 71
4
votes
2
answers
256
views
What is the function of this dual current regulator symbol?
I am trying to implement the NE572 compander in a circuit simulator, but I am unsure what the behavior of this symbol is.
It appears several times throughout the datasheet, sometimes with a value and ...
- 153
0
votes
1
answer
65
views
Design Strategy for 5000/5+5A Dual Ratio Resin Cast CT: Single Core vs. Dual Core Configuration?
I am currently designing a Resin Cast Current Transformer and am looking for advice on the best core/winding configuration to achieve a dual output for both metering and protection.
Here are the ...
- 13
6
votes
6
answers
934
views
Understanding the current mirror example from Electronic Principles
In the book Electronic Principles 9th edition (Albert Malvino, David J. Bates, Patrick E. Hoppe), there is this example of the current mirror circuit (chap 15, p660):
And this explanation :
If the ...
- 139
0
votes
1
answer
130
views
PFC MOSFET and Current Sense Resistors Failing After Startup
I have designed a 24 V / 10 A SMPS with an active PFC and LLC stage. When I apply the AC input supply, the circuit powers up normally, but after 5–10 seconds the following failures occur:
The PFC ...
- 161
1
vote
1
answer
76
views
Battery Charger IC Power Path Management control
In this Battery Charger IC, there is the power path for the system load (OUT) and a path for the battery charging (VBAT).
When the CE pin is low, on page 16, we can see that the path from the input ...
- 2,035
1
vote
0
answers
54
views
What does the 'af' marking on the resistor mean? [duplicate]
The photo above shows dfrobot's current-to-voltage module.
Looking at the board photo, there's a resistor marked "af." What resistor is this?
Also, what is the role of the af resistors (R2 ...
- 167
0
votes
1
answer
75
views
Is a 60 degrees Celsius temperature rise acceptable for ESC PCB traces when using top + bottom copper with via stitching?
I am designing a BLDC ESC PCB for a quadcopter drone and I want some advice and opinions on the coper traces that carry the high current (max 18 A).
PCB details:
4-layer PCB
Copper thickness: 1 oz (...
- 547
1
vote
1
answer
161
views
Dacia Logan speedometer circuit board: 6 LEDs don't light up
I am trying to understand why only 6 LEDs are not lighting up. It is a speedometer from a Dacia Logan. All the LEDs work except the 6 in red in the image below (3 on the left and 3 on the right). All ...
- 19
0
votes
1
answer
86
views
Current sensor worst case output voltage calculation
I am trying to calculate the worst case output voltage of a current sensor, without considering the temperature drift of the parameters. The sensor datasheet mentions offset voltage, ratiometric error ...
- 145
11
votes
1
answer
527
views
How can boost converter li-ion 9V batteries achieve low self discharge?
I bought several li-ion 9V boost converter batteries intended to replace 9V alkalines, chargeable with USB-C. These batteries have a 1 Ah 3.6 .. 3.7 V li-ion cell and a boost converter creating ...
- 2,667
5
votes
2
answers
588
views
What is the 110 volt AC power consumption in watts when using a USB wall wart outputting 2 watts at 5 volts DC?
I want to know what the 110 volt AC power consumption in watts is, when using a USB wall wart that is outputting 2 watts at 5 volts DC?
I understand that if the conversion was 100% efficient, then the ...
