# All Questions

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### PV + MPPT controller modular design for low sun irradiance applications [closed]

I am trying to build an MPPT charger for SLA batteries. I have not yet studied extensively the MPPT technology. Most of aliexpress MPPT charger designs come with the premise that PV voltage (open ...
33 views

### Turn-off voltage for SiC modules, does it always have to be negative?

I have been using SiC power modules for my application.Normally we use negative voltages at the gate to turn-off the modules. Would want to know if the power modules can be turned off with the zero ...
80 views

### How can I calculate the amplitudes of this signal's harmonics?

How can I calculate the amplitude's of the harmonics? This signal is the voltage of a capacitor bank. There is a few amperes of current on the capacitors in form of PWM. On the signal the 200mV Jumps ...
41 views

### Example of computation of S matrix

Let's consider the slide 1 of this material. I have understood the computation of S11, but not that of S21. I do not understand: - why there is the circuit with V and two impedances Z0 and there is ...
60 views

### Total Capacitance In A Circuit Along With Other Electronic Component

I know it may sound stupid but having thinking across my mind with the basic knowledge I've already have with capacitance(series and parallel), I've been wondering on how to get the total capacitance ...
95 views

### How to mount a PCB in a project box

Hi nearly finished my first electronics project and I need to think about how to mount it into a box. I feel like I am missing something absolutely obvious with how to use PCB spacers. Here is a ...
29 views

### Charging battery with external charger while powering load

I am building a device which I would like to be able to charge with several different types of external battery chargers (different Icharge within spec of battery, of course). If I understand ...
199 views

### What is the purpose of resistor?

LM311 datasheet, page 18: Is it a hysteresis so that when transistor opens, the reference voltage goes up? Or is it related to input signal filtering (then what is the corner frequency?). Can you ...
28 views

### RF Power Meter vs RF Power Sensor

What is the difference between a power meter and a power sensor? If I got this right a power meter is the instrument that reads and displays the measurements of the power sensor. Also, power meters ...
46 views

### What is the difference between these ring oscillator topologies? How can I simulate one without “noise voltage?”

If I understand correctly, with ring oscillator, it adds the negative feedback back to the loop to make a supposedly infinite gain. With the first topology (NMOS inverter) the negative feedback adds ...
29 views

### Altium - Linking Sheet Entries/Ports with Net Labels

I am struggling to find a way to get the compiler in Altium to see a Sheet Entry/Port (tried with both) and a net label on the same sheet to link. This redacted schematic page shows what I have (this ...
25 views

### IR Proximity Sensor Not Responding

I'm trying to build an IR proximity sensor using a simple tutorial found online. Here is the schematic and here is the link of the tutorial : https://www.instructables.com/id/IR-Proximity-Sensor-1/ ...
31 views

### Measurement of Resistor Parasitics Inductance and Capacitance

I have seen people doing some measurements of parasitic capacitance and inductance of some resistors, by using a vector analyzer and analyzing the graph of S11 with respect to frequency. To get this ...
20 views

### Finding Rise time and Fall time with Slew Rate Specification

I am using this QSPI Flash Memory IC I'm operating the QSPI clock at 48MHz. I am probing the Clock and Data signals in my scope. On Table 54 which is on Page 128, we have Rise time and fall time ...
25 views

### Superscalar pipeline of degree 4: find MIPS rating and time interval between instructions

So a superscalar MIPS system has two degree 4 superpipelines each of which has 5 stages and 1 Ghz clock rate (assume no stalls). Part 1->Finding the peak MIPS rating. I know that MIPS formula is ...
80 views

### Why my current mirror results in wildly different currents?

Let me start with that I'm new to current mirrors and my idea may be conceptually wrong. Feel free to ask any clarifying questions. I'm designing a dual "LED lamp" with very finely tunable brightness ...
29 views

### LoRa RFM95/SX1276 libraries for PIC 8 bit microcontrollers

I recently finished prototyping a LoRa RFM95 transceiver with an Arduino Uno using the RadioHead RFM95 library. I am now transitioning to designing a PCB for my project and chose a PIC16F18446 ...
65 views

### Understanding equation for capacitor-voltage

For an simple RC-network the following solution of an ODE is given: $u_c=A_1+A_2\cdot e^{\frac{t}{\tau}}$ I fully understand how the solution is calculated, but I want to have an feeling for it.. ...
33 views

### Energy Meter power supply advice/help

I've been assigned to start working on a smart energy meter project, it's been like 10 years since I put any work in AC. I would be sincerely grateful for any constructive advice. Now the 3-phase ...
20 views

### Doubt on how to do well done loop shaping of a control system

I am studying control systems, and I have some arguments that are not clear. In particular I am studying the loop shaping design using H- infinity controller designed with muxed sensitivity, in SISO ...
33 views

### How do I balance a low-impedance signal?

I often use direct boxes to convert a high-impedance guitar or keyboard signals to low-impedance and then balance the signals for sending on a long run to the mixer. Now I want to take an unbalanced, ...
32 views

### PIC24EP: What exactly are IOL, IOH currents

I'm going through the 'Electrical Characteristics' section of datasheet of PIC24EP128GP206 to find out minimum and maximum voltages and currents specific to GPIO pins. While doing so, I came across ...
2k views

### Why is inverting op-amp behaving like a low pass filter?

can anyone explain why this circuit behaves like a low pass filter despite having no capacitor in the feedback loop?
35 views

### Voltage selector circuit. I tried but couldn't find a way to block [duplicate]

I want to make a voltage selector circuit with opamps, capacitor, diodes only (Transisors and other IC's forbidden except only for opamp). But I couldn't find a way, do you have any advice for me ? ...
74 views

### Homemade Sata3 pcb backplane desing [closed]

As seeing proteus drawing all ways going directly. There is no electronic component. Considering this computer cant see disks http://vomro.com/pro.jpg 3d files http://vomro.com/x1.jpg http://vomro....
84 views

### How to drive an 100 mA forward current LED using STM32H743 Microcontroller to the collector without using external power supply?

I am new to electronics hardware so kindly help me and give me suggestions. I am working on STM32H743 microcontroller for dual camera interface and LED interface. The total current of my STM32H743 ...
25 views

### Define break-away and break in points for root locus analysis [closed]

Define break-away and break in points for root locus analysis.
24 views

### I need sensing ADC use mux with stm32

There is an LED connected in parallel. If one LED is damaged and the ADC value reaches zero, the MCU detects this. So I designed the circuit using a multiplexer for this logic. However, it is ...
49 views

### Analyze a MOSFET circuit with device caps

I am trying to analyze a small signal circuit like following with all device caps considered. I find it rather complicated when all device caps are in play and would like to know if there's any ...
37 views

### calculate rpm motor to drum roll rpm [closed]

I have a machine used the motor to drive a press roll(a small roller) that sends power to drum roll (big roller). I need speed 27 rpm for Drum roll and how many RPM for the motor that drives the ...
33 views

### Is there such a thing as analog and digital compatible cmos or ccd sensors?

I'm way over my head with this one but I am trying to learn about cmos/ccd(preferred) sensors in order to build my own camera. Looking to get analog video from a sensor in a very small package size &...
35 views

### Calculating voltage drop (and power requirements) for multiple devices

I am trying to calculate the power supply required for 3 cameras (1A each), each with 150 metres of cable (0.75mm2), connected to a common power source (AC-DC PSU). I have done these before with ...
99 views

### what is the nature of output data? [closed]

I want to know whether I can get data from this port to avr microcontroller with lcd display through usart. I want to know whether the output waveform is TTL or RS232 or other form. Can you say ...
38 views

### How can I know which constellation diagram has a lower symbol error just by looking?

So for the following example: How would I know which is less prone to error? $$C1=[−3−3j,−3+j,1−3j,1+j,−1−j,−1+3j,3−j,3+3j]$$ C2=[−3\sqrt2j,−2\sqrt2−\sqrt2j,2\sqrt2−\sqrt2j,\sqrt2j,−\sqrt2j,−2\...
22 views

### CAN BUS Termination Resistors For CAN Logger Device

I am making a CAN logger device that will be connected to the vehicle OBD port. Since the CAN bus inside the vehicle is already terminated, do I need to terminate the BUS lines on my device end, right ...
14 views

### Why do I get this LTspice Error message ‘Unknown VDMOS Level :3’?

I am new to LTspice and following this tutorial : http://www.simonbramble.co.uk/lt_spice/ltspice_lt_spice_tutorial_3.htm I am using the proposed Jig : LTC3878 buck converter that use 2 MOSFET, ...
44 views

### How do I convert a Eb/No from a dB value to a linear value

So for example how would I convert an Eb/No value of 2dB into a linear value?
33 views

### EPS12V 8pin from ATX PSU with two separate 12V rails

This is your standard EPS/ATX12V connector used for feeding the main processor VRM on a computer motherboard. The two 4pin connectors can be attached together to create an 8pin connector. The top four ...
41 views

### How to invert PWM signal on STM32

I am trying to control a WS2812 LED with STM32F103. The LED is a digital RGB LED also known as Neopixel. They are controlled by sending 24 bits of color data per LED to the first LED's data pin. The ...
28 views

### Combinational System Theoretical Question

I'm currently taking an MIT-OCW course, where it says that a system built from smaller combinational systems following the following compositional rules is combinational: Each component of the system ...
45 views

### Simplifying a MUX's truth table

I found this truth table for a 4-to-1 MUX: (circuit for context) I know (I think?) that if I were to make a truth table with 2^6 variables and simplified it I'd get the same SOP as I'd get with this ...
50 views

### Simple circuit analysis with node potential method

I can't find the correct solution for this exercise and I can't figure out why. simulate this circuit – Schematic created using CircuitLab The question is: What is the current $I_3$ ? (...
15 views

### Best dielectric filament for capacitive touch pad overlay?

I'm using the MPR121 to detect capacitive touch for several adjacent buttons. I want all those buttons to be covered by a single 3D printed overlay (which will be about 2-3mm), so that touching ...
81 views

### Circuit to limit a set of outputs so that only one is on

Background: I have a set of irrigation control valve solenoids (24V ac) that I control via a set of mechanical relays with the GPIO pins of a microcontroller (ESP32). The power supply does not have a ...
66 views

### 65V Square wave Switching Circuit

I am trying to generate a 65V square wave very similar to the post found here: Mosfet PWM signal not square My load is in a slightly different configuration (i've tried them both ways), but the ...
73 views

I was hoping someone here might have an answer for this - is there a version of the 4017 decade counter that is TTL, not CMOS? I'd like to create a project for a bunch of 11 - 12 year olds and I just ...
29 views

### piezo element vs accelerometer

I'm looking at options to detect forces applied to a car door. An accelerometer seems by far like the most popular option, but I was also considering placing several piezo elements inside the car door,...
44 views

### Determine cell tower operator

Pre: I'd understand if this isn't strictly related to electronics but I believe that this is something that would interest electronics enthusiasts. I have a cell tower 2 buildings down from mine. I ...