# All Questions

113,201 questions
79 views

### Three phase AC machine

I have encountered a three phase ac machine whose name plate contains following information: Y/360 V/90 Hz/2,3 A. I don't know whether it is an induction machine or permanent magnet synchronous ...
37 views

### PI controller - DC voltage regulation

I a voltage source converter, in order to control the DC-Bus voltage a PI controller can be used. The control method is illustrated in the figure below: I would like to ask why the input of the PI ...
99 views

### What type of connector is this (see picture)?

I could not find out what type of connector this is. It has a width of approximately 10mm, 0.5mm pitch, and 30 pins. I assume it is some kind of diagnostic port. It is part of a mobile device with ...
25 views

### Keypad controlled variable 18Vdc power supply [on hold]

I have design a mains operated 18 VDC variable power supply. However the on/ff and voltage setting is currently controlled by a switch and knob. I would like to fit a keypad with 3 "buttons" to ...
41 views

### Push Pull Switch Mode Power Supplies

I am reading this material for understanding the switch mode push pull power supplies. Push Pull Switched Mode Power Supplies I am unable to understand the working though. Can someone provide a ...
19 views

### different modes for analyzing the acceleration in an AC motor [on hold]

I searched a lot on the internet but I still can't understand what the different modes are for analyzing the acceleration and which one is better. I need the data from an accelerometer for condition ...
130 views

### Getting CPU clock signal out of computer (as to measure externally) [on hold]

I've been searching on the internet some clock generator module capable of reaching up to 1GHz, when I just realized that the machine I'm using to search has one CPU with its own 2.5-3.0 GHz clock... ...
30 views

### Altium pin parameters in symbols

thanks for the many great questions and answers over the years. This is my first question. I use Altium Designer for capturing designs. I had an idea to make my processor components a little more ...
46 views

### What should be the output resistance of this source with series diode?

Below shows three sources with open terminals: simulate this circuit – Schematic created using CircuitLab In Figure 1 if we want to calculate the output resistance, according to the linear ...
49 views

### Reliable sensing method for device inside a parcel to detect when/if the parcel is opened?

I'm wracking my brain for reliable ways for an electronic device to detect when/if the parcel it is sealed inside is opened. The device will be sealed inside the package and activated via Bluetooth ...
29 views

### Wha't the difference to use the junction to case thermal resistance instead of the junction to lead thermal resitance?

In case I have a diode, and I want to know it could dissipate the power, I have two values, but I can't choose between them: - Junction to ambient thermal resitance $R_{ja}$ - Junction to lead ...
61 views

### Help! “Ground Loop” preventing new PC from booting with Cat5 plugged in. Is there a fix? [migrated]

I just built a new PC for a friend. Everything works perfectly in my home but not his. But when I delivered it and plugged everything in, we were plagued by (I'm assuming) Ground Loop issues. His ...
73 views

### Circuit To Measure Phase difference

Is there any classical analog circuit to measure the phase difference between two analog signals ( especially sinusoidal signals )? I want to measure the phase difference between two sinusoid signals ...
31 views

### Strange SDRAM Behaviour

i try to use the SDRAM on my DE0 Board. This is the chip: http://zentel-europe.com/datasheets/A3V64S40GTP_v1.3_Zentel.pdf Basically my driver works. i save the value of an upcounted signal in the ...
52 views

### RBG LEDs for visible light communication

What kind of RGB LEDs are used in visible light communication? I want to buy them but i do not know any of those LED product name, model or something.
35 views

### What part of Ebers-Moll equation shows the decrease of the collector current in saturation region

By looking at the Ebers-Moll equation for a BJT transistor: Is this formula explicitly showing why Ic starting to decrease towards zero in saturation region. Which part of the equation shows that?
16 views

### shortcut to change layer/add via while routing in Altium doesn' t work

I'm trying to change my tracks during routing to pass from bottom to the top, or from top to bottom using +/- buttons, but neither numerical buttons neither +/- buttons from keyboard buttons are doing ...
27 views

### Two bit upcounter moore

I am to construct the state machine for a Moore two-bit up-counter with a synchronous reset. Output is 1 if the current count is 0, (state 00). Binary upcount if x=0 and in Gray if x=1. My attempt: ...
84 views

### Step up 5V to a range of 7V - 12V

I am working with the STM32 MCUs and I wish to step up a 5V pin to a range between 7V and 12V. In summary I wish to power the second Board from the first board. Thanks for any reply.
60 views

I made a terrible mistake connecting -15VDC to the pin 18 of AD7849 instead of pin 17 and powered it up for a minute until i understood the problem.It was without the protection diode for power supply ...
50 views

### What is this component? “KE_7CA_”,“E1W_74”,“83S”,HC14"

[][]2Would you please tell me what is this component?
46 views

### Logic level converter for SPI

I'm using an SPI interface in Raspberry Pi for programming platforms. I have a need to use various logic levels (1.8V, 3.3V, 5V). Is there any IC which allows for dynamic switching between logic ...
54 views

### Minimum connections needed between stm32 MCU and the st-link programmer?

My MCU is stm32L432kc. I've concluded that we need a minimum of 4 connections: SWCLK, SWIO, vcc and gnd. Can someone from here confirm that? And another question is I'm confused how to connect the ...
30 views

### How to determine PWM Frequency of a MOSFET to drive a BLDC motor?

What are the factors determining the PWM Frequency of the MOSFET driver circuit that drives a BLDC motor. Is there any equation for PWM calculation? For eg. I need to control the speed of a BLDC ...
35 views

### Difference between input current and supply current?

I am reading and trying to understand datasheet of ICs. I am reading this datasheet now : http://www.ti.com/lit/ds/symlink/sn74hc00.pdf In the table 6.5, there are two parameters namely Ii and Icc. ...
23 views

### python script send packets IP through universal modem [on hold]

I have a few different brands modems (Sierra wireless wp7702, quectel bg96, ublox SARA R410M, etc) and I'd like to make a python script to universally send IP packets to modems using ATD and then ...
47 views

### If my battery light comes on while driving and had a bad odor and won't start , what could it be [on hold]

I was doing my 200o 5 speed Nissan maxims with parking break, then battery and break light came on , then a odor came about . Pooped the hood and smoke was coming out and notice something fire red . ...
78 views

### Is it possible to connect a smartphone/tablet OLED screen directly as a PC monitor? [on hold]

why? Why OLED? mainly because of best contrast by having no backlight annoying leakage. Why smartphone or tablet screen? because of size, resolution and price. usage requirements, previous tests, ...
55 views

### Can I use a pc case fan for a tumble dryer?

My tumble dryer is broken. I found the service manual online and according to the error number the heat pump fan is the problem. I open it up and to my surprise I found a standard sized case fan in ...
19 views

### Problems with Switch Marvell 88E6060 with high temperature

I having issues with the marvel switch 88E6060. https://www.marvell.com/switching/assets/marvell_linkstreet_88E6060_datasheet.pdf When the system reach the temperature of 80ºC the PC doesnt detect one ...
64 views

### Freewheel diodes and shoot-through prevention required on this low-voltage H-bridge?

I have built the following h-bridge: VMOT1 is at logic level (3.3V) FWD and REV are driven by MCU (no PWM in the scope examples given) Q7/Q8 are DMP1045 Q9/Q10 are BSS138 D3/D4 are 4 x 4148 the 2 ...
41 views

### Voltage reduction issue in circiut

I have two electrical network which I want to power using a single power source. I am using a 3 cell lithium polymer 8000 mAh 30 C for it. One of the network consume 40 A current and the other ...
70 views

### NanoPi Neo4 Power supply scheme help

Title might seem a little misleading, but honestly quite hard to word a title for my particular problem. The board design I'm working with combines the NanoPi NEO4 minus specific components which I ...
53 views

### Vary the Vpp of sinusoidal oscillator

For an assignment I have to create a sinusoidal oscillator with 5 Vpp (centered around 0 V) oscillating at 10.0 kHz. The oscillator works as expected, at the right frequency, but the voltage needs to ...
22 views

### GPS to PIC Microcontroller to XBEEPRO S3. Data from GPS becomes distorted after passing XBEE

We are using XBEE S3 as a transmitter of data taken from the GPS. The GPS data passes the system this way: GPS-PIC-XBEE. The GPS data that we are receiving on the other receiverXBEE becomes distorted ...
31 views

### Understanding Optimization/Realization of the voltage controlled current source

I am unable to make a voltage controlled constant current source. So I am using the following scheme (Sorry for bad sketch drawing): The constant control voltage varies in the range of 0 to 5 V is ...
16 views

### JTAG- Daisy chain with openocd but only the first device is programmed

so i am trying to flash 2 devices in a JTAG-Daisy chain. The problem is only one device is flashed. I don't really understand the command flash probe and ...
1k views

### Why do LCR meter manufacturers give the details of measurement frequency to us?

When you want to purchase a DMM, more probably you don't see at what frequency the DMM you considered would work, but in the situation you're considering to purchase an LCR meter, manufacturers give ...
20 views

### GPON controller chip [on hold]

Does anyone know which companies manufacture GPON controller chip (for ONU modems)? Any part numbers would be greatly appreciated. I only found Broadcom, but Broadcom doesn't provide datasheets ...
86 views

### What is this thing called

I used to use this thing to setup variable load to my AC output. It is a smoothly variable resistor, Just slide, and resistance vary smoothly unlike Decade Resistors.. But I cannot remember the exact ...
66 views

### RIght reasons for using a voltage regulator for DC motors

I read in an online book at https://www.learncse.com/images/Lessons/Lesson_14.pdf following reason for using a voltage regulator to power DC motors. While I understand the importance of using a ...
28 views

### Sensing Of Load In Induction Heating

In New Induction Appliances When you lift the pan from surface of furnace they automatically switch off the power of furnace so my question is How Induction Cooking Appliances Can Know The ...
23 views

### How over-discharge protection function works on this circuit?

How this circuit to protect so call "over discharge"? since there's no output + and - terminals on the board and this case the load should connect directly to B+ and B- without any protection for ...
49 views

### Ignition coil transformer

Urgent! Need answers ASAP! I recently built a HV power supply, as per the link (using a pencil ignition coil). However, I used a capacitor of around 5nf, which meant the supply did not work. The ...
45 views

### hybrid vehicle DC voltage boost

if i join two battery cells in series then the voltage will be added. what if i replace one of the two battery cells with a DC generator? My reason is because batteries (excluding Lipo) have modest C ...
16 views

### What is the use of Level Set and 12AU7 circuit in Pilot FA-540 tube tuner radio?

I recently scored a Pilot FA-540 tuner on eBay. The one I received was from a console. But the models sold usually is the non-console type. So, while going through the circuit from the service manual ...
20 views

### Co-Processing Across SBCs

Situation: Was thinking about co-processing as I played with the Adapteva Parallella, which has a quad-core CPU and a 16-core RISC-based co-processor. Question: It got me thinking -- can I achieve ...
13 views

### Heathkit IP-27 bench PSU min. stays at 0.18V and there is a +0.1V for all the readings?

I've recently acquired a Heathkit IP-27 bench power supply. The supply itself works quite fine except that the minimum voltage it can be turned down to with the coarse adjustment is only 0.18V, doesn'...