# All Questions

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9 views

### What does worst-case gate capacitance mean in a MOS transistor?

I have searched the statement; MOS worst-case gate capacitance in various forms but no avail. Keep in mind I'm a student. The course I am taking has no reference material. With note slides with ...
13 views

### Calculate the current

I was practicing for the exam suddenly I found this question the professor solved, but I think whether he or I made a mistake. Part (III) in the image. His calculation is on the image he added the ...
30 views

### Most expensive parts [on hold]

I was wondering, what is the most expensive part on Digikey - or Mouser, or any supplier. I have done research to try to figure this out but I was unable to.
12 views

I am doing I2C project with MPU6050 using STM32F4DISCOVERY board. The ADDR bit in SR1 register is clearing in one instruction execution without reading SR2 register. Because of clearing ADDR bit, I ...
14 views

### Internal resistance of an analog ammeter [on hold]

Why does the internal resistance of an analog ammeter decrease with the range used?
13 views

### Is there a way to create synchronous serial data without a sensor?

I want to work on small a project where an SSI-output data(angle data) of a rotary-encoder will be read by a microcontroller board(such as Arduino board) and the microcontroller will then send this ...
13 views

### Calculating LCD display horizontal and vertical porch values

How should I set the porch and sync values given an LCD display? For example, say my FHD (1920x1080) display datasheet says its has a total vertical cycle of 1125. I have 45 clocks remaining (...
35 views

### MOSFET, the effect of the gate voltage

Here the gate voltage is 5V and lots of the 12V input voltage stays across drain and source. Here the gate voltage is 12V and still some voltage stays across drain and source but this time smaller. ...
19 views

### Testing 18650 Batteries in Bulk

I am coming into possession of hundreds of 18650 batteries. They are used, but initial checks indicate over 90% of them are good batteries. I would like to discharge, charge, and measure capacity of ...
14 views

### Ceramic capacitor markings unknown - help identify Xa and AM2

I am trying to identify ALL of the markings on this capacitor. Originally I was only trying to determine if it is X1 or Y1 class (I still am). The X and Y marking on this capacitor don't appear to be ...
63 views

### How is circuit topology chosen in analog designs?

Suppose I'm an experienced analog designer, e.g., RF, power electronics, ADC. How does choosing a circuit topology fit into the overall workflow for a typical work assignment? I imagine my manager ...
45 views

### What can happen to a relay at temperature outside of its spec?

I am building a system for measuring some parameters in a climate chamber. The test runs from -55 to +125°C. I need to switch some signals between multiple devices under test using relays. I want to ...
35 views

### linear model of a power load at the end of a transmission line

I am working on a controller that will regulate the voltage at the end of a transmission line into a variable load. I am able to ignore the inductive effects of the line at the frequencies of interst, ...
20 views

### What factors do I need to consider when selecting an inductor to use in a circuit with the MT3608?

I am trying to use the MT3608 chip to boost the power output of a 3.7V lipo battery from 3.7V to 5V, which will ultimately power an ATMEGA32U4 chip. Below is a picture of my circuit where I have ...
24 views

### Carbon tracking on coil

I built this circuit using a relatively small two wire ignition coil. https://www.instructables.com/id/Variable-voltage-ignition-coil-power-supply/ When I ran the circuit, no spark occurred meaning ...
43 views

### Is current direction always opposing when signals are reflected on a transmission line

Having read Dave Tweeds excellent description of reflections in electrical transmission lines, I thought I was one step closer to a full understanding of SWR. However, later I was watching w2aew's ...
27 views

### Simple LDR circuit calculate average time between triggers

I am a beginner with some past experience in electronics. I have a circuit that uses an LDR and 555 to display the time (lap time) between the LDR being triggered - start / stop - on a 7 segment unit. ...
46 views

### When should we NOT simplify a digital signal in an expression?

When we do a simplification in a Boolean expression, sometimes we eradicate some Boolean variables, either from part of the expression or entirely if it's not needed. Is there a case in digital design ...
27 views

### Does MAX3665 amplifier have a minimum operating frequency?

I am using the MAX3665 in a design. The amplifier has an IR Photodiode at the input and is failing to detect any signals. My signal generator outputs a maximum of MHz square waves and MHz sine waves. ...
34 views

### How does this linear actuators know absolute position of their carriages?

As title, I can't find out how main system of this linear actuators knows each carriage absolute position. This system is iTRACK from Rockwell, but there are some other brands that do this. Here an ...
25 views

### First bit of NRZI

I was searching for Non-Return-to-Zero Inverted, but no references I couldn't find any reference about the first bit in NRZI. I know that, in NRZI, 1 refers to <...
36 views

### Design a sequence detector which can detect 1101 and 0110 *simultaneously*

I'm working on a problem of implementing a sequence detector that outputs 1 whenever it detects 1101 or 0110. I know how to implement single sequence detector. Can anyone help me design this ...
34 views

### Need help with level shifting and amplifying a signal

I have a 1V pk to pk analogue signal and need to shift and amplify the voltage to 0.5-2V.The supply into the amplifier is ±10V. The frequency of the signal is 500 - 1000Hz. What sort of circuit ...
15 views

### TLP281-4 optoisolator circuit question

I am working with TLP281-4 optoisolator, there is a board which used this IC in it. It connected like this: Why can't I connect 5V to the collector and take the output directly from between emitter ...
23 views

### GPIB/SCPI Error Codes

I'm using a modern NI USB-GPIB adapter with NI-MAX 19/488.2 to query an Agilent E8361A VNA with SCPI commands. Commands such as *IDN? and ...
30 views

### Switching between series and parallel battery connection

Previously I made same scheme (attached) but with two relays and it worked pretty well. Now I want to rebuild it with transistors (MOSFETs). The main purpose as I mentioned in the subject is to ...
17 views

### Finding voltage gain and current gain using the load line in a common emmitor transistor amplifier

So this question is really annoying me for a while so I needed some help. I am given the output characteristics curve for a CE transistor amplifier. I also managed to draw the load line. They have ...
43 views

### Does 18650 cell voltage sag have a direct relationship with its internal resistance?

When a cell is connected to full load does it drop some of its voltage due to internal resistance and quickly jumps back to normal whenever the load is taken off??
36 views

### power consuption of internal 32kHz RC oscillator

I am looking for the typical power consumption of the OSCULP32K (Ultra Low Power Internal 32kHz RC Oscillator) of ATSAMC20J18A. Found nothing in family datasheet so far, only XOSC32K. Can I expect the ...
44 views

### A sensor for jaw/mouth movements in a mask

The mask I'm trying to build will display different lighting patterns. The overall goal is to synchronize these patterns with a musical/dance performance, so there were two options: either hard-code ...
20 views

### Drawing a single pixel using DMA2D

I'm trying to draw a single pixel using DMA2D. I did the following code it's not working at all. LCD Display Width is 320, Height is 240. I assumed a 1x1 pixel rect as a pixel. ...
31 views

### Conformal coating of shielded RF modules

What is the best practice to protect a circuit with shielded RF modules? I have a feeling that conformal coating is difficult since the shield is not sealed.
48 views

### What is the problem in my timeout implentation?

I'm trying to use DHT22(temperature and humidity sensor). Here is it's datasheet DHT22 Datasheet In first few seconds. I can get values. But after a while it stucks in here: So i try to implement a ...
49 views

### why the voltage at the gate terminal is 1.8V irrespective of the 3.3V pull up?

[![the output of my GPIO is 1.8V which is pulled up to 3.3V using a 4.7K resistance and that gpio is connected to the gate terminal of a P-channel mosfet, when i measure voltage across the gate ...
37 views

### Industrial grade electric motor near 50mm outer diameter and 100Nm rated torque. Does it exist? [on hold]

I'm looking for an electric engine for industrial application to work in a machine where maximum diameter to fit it in is 53mm. While there is no length limitation it should have reasonable value, ...
19 views

### Mounting Problems SD Card and STM32F7 Discovery

I've got some problems with the FATFs library and the STM32F7 Series. I want to connect a SD-Card (32GB, SanDisk, FAT32) with the F746G-Discovery-Board to save some data on it. (at first .txt-Files, ...
34 views

### Automotive connector ID- tentatively solved

I have a 1998 Dodge Durango and am swapping transfer cases. The new case (NP242) uses a 4-pin switch (see photo). Dodge discontinued the adapter harness some time back and I have not been able to find ...
49 views

### What type of fuse is this? [on hold]

I have a device that is missing a fuse (see attached pic). Could anyone point me to a site that sells it?
22 views

### Confusion with serial communication standards when sending sync serial data to a PC thorugh its serial port

When I read about SSI communication I can see that a pair is used for clock and another pair is used for data transmission as follows: On the other hand if I read about RS422 all lines are data and ...
14 views

### AT90CAN128 iocanxx.h vector numbers

The vector numbers in this header do not match the vector numbers in the manual AT90CAN128 doc7679 pdf Section 8.1 They appear to be one position out Can anyone advise on which is correct?
9 views

### Possible Issues with battery Powered sensor and collector star network

I am designing a wireless Sub-Ghz network consist of many battery powered sensor nodes with a single collector node. For lowest power possible, the sensor stays most of the time in sleep mode waking ...
37 views

### Transistor for USB Hub power control

I'm trying to add power control to a USB hub based on the Terminus Tech FE1.1s hub chip. From the datasheet, I know the chip supports ganged power control, so all ports share a single switch. That's ...
22 views

### Thermal resistance of Thermal Interface Material

Can anyone please give information how to calculate the thermal resistance of SIL PAD "TSP A2000" from make Berguist. from The data sheet its specified thinness is 0.254mm, Thermal conductivity (W/m-...
18 views

### Does CP2102N-QFN24 has native support for Android 8.0 or above?

I want to use CP2102N-QFN24 USB to UART chip with Android phones having API 26 and above. Does this chip has native support for Android phones with API 26 and above or need to download/install some-...
33 views

### Accelerating Graphics rendering in STM32F7

I have a framebuffer that is created on SRAM with LTDC that is everything is written to that buffer, images, icons,..etc. and get displayed to the LCD screen. That works fine. but the screen size is ...
57 views

### Correctly driving dual 7-segment display

After receiving some feedback on my other question, I have improved my design. I am still using a stm32f030k6 to drive a two-digit 7-segment display, but I am using the common-anode HDSM-291C in ...
26 views

### Derivation of diode voltage in three phase full wave diode rectifier

Considering ideal diode in 3 phase full wave diode rectifier we can present the system in picture below. I found the final equation for $v_{D6}$, but can not figure it out how it was derived. \\$v_{...
28 views

### Pulse Down a line with Series terminations between transmission lines

I am interested in a relative edge case in transmission line of a simulation. If send a pulse down the setup below, now obviously my rudimentary steady state electronics knows this is a basic voltage ...