All Questions

0
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0answers
4 views

Help debugging problem in light meter power supply

I have an old Sekonic light meter (L-778) that was reporting no battery when batteries were installed, and emitted a high-pitched whine that changed in pitch when powered on and off with the battery ...
0
votes
0answers
6 views

Testing the presence of GFCI Auto-monitoring Self Test circuit

http://www.internationalconfig.com/icc6.asp?item=74900-RCDS According to the supplier of this generic universal made in china 240v GFCI (with 6mA tripping) receptacle (these are OEM in many other ...
0
votes
1answer
20 views

What's the magic behind inverters?

I'm having hard time understanding how inverter works and why it works. I mean why is it possible to power a say fridge (220V AC) with a 5v battery using a 5v to 220v inverter ? And since this is ...
0
votes
0answers
15 views

Delay timer for car bar light to stop mode cycling

I just brought a bar light for my vehicle. My problem is the light has 4 modes (white, white flashing , yellow, yellow flashing) and the modes are triggered by turning the light off then on in less ...
0
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0answers
10 views

total transfer function of a LTI System with feedback

I have calculated the transfer function of such systems many times, but now i feel like I`m going around in circles. I have drawn a few help-signals to help me solve it, but they are dependent of one ...
0
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0answers
16 views

FreeRTOS PID Controller (stm32duino)

I'm currently working with embedded system implemented on SMT32F103C8T6 Blue Pill microcontroller based on FreeRTOS. I want to control the velocity and position of DC motor using PID controller. For ...
0
votes
1answer
24 views

Relay Circuit Explanation

I am trying to understand relay circuits better. I have two circuits in question below. Left Image I understand Pins 2 and 9 are the coil contacts. I would wire a microcontroller outpin pin to a ...
0
votes
1answer
18 views

What happen to a dff(flip flop) without input?

I have this question but I don't know what happen to a dff without an input is it always 0 ?? like this picture below the 2nd dff hasn't any d ??? Also, if someone can draw the answer of the question ?...
1
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0answers
31 views

How is CAM implemented?

I have a book statement: A content addressable memory is a circuit that combines comparison and storage in a single device. I want to know how this is implemented in real world? Sounds like an ...
0
votes
1answer
12 views

Depletion Mosfet as current source to power load

I came acros the following application note for a Depletion Mosfet (https://www.infineon.com/dgdl/Infineon-Application_Note_Applications_for_Depletion_MOSFETs-AN-v01_00-EN.pdf) and i got intrigued. ...
0
votes
0answers
19 views

Dell Battery slice red flashed [on hold]

Dears There any one help me about problem in Dell battery slice is give error when I have charging directly is red flashing after 5 second of charge pluge continusslly When I inserted to computer it ...
0
votes
1answer
16 views

Average Power of load conected to an Ideal Transformer

Where does the 1/2 come from in the power equation?
1
vote
0answers
14 views

Communication Theory - Determine efficiency of this protocol

My solution: I have no idea if what I did is correct. I'm getting a bit confused differentiating between 500 frames/minute and the 4.8Gb/s, they both seem like transmission rates to me. I'm assuming ...
0
votes
0answers
16 views

PWM Duty Cycle Threshold Switch

I'm trying to make a switch for a PWM signal. I am controlling a PWM signal however I can only control the duty cycle from 50% - 100%, for various reasons I can't change the controller. I want to ...
2
votes
2answers
51 views

Determining Impedances of an Op-Amp Circuit

I'm trying to review some old concepts, and thus far, there was one that I couldn't really understand: impedance of circuits involving op-amps. Assuming an ideal op-amp, it has infinite input ...
0
votes
0answers
28 views

Off the shelf 25W / 470kHz / 50Ω impedance sinusoidal wave generators?

Various RF-based equipment exists to treat muscle pain, arthritis and beauty. The principle is to produce heat deep inside human tissues. This is accomplished by placing a body part like a knee joint ...
0
votes
0answers
16 views

How to pick a compatible constant current LED driver?

I have a ceiling light which is LED which just blew. When I turn it on, the LEDs dimly glow for a second before stopping. Here is a picture: To me, it seems like three 8 LED strips in series, each ...
0
votes
1answer
33 views

Three stage amplifier

Well I need to design three stage amplifier Im stuck on the output stage, I need that the AC Current on the load will between 20mA to 100mA, but Top current I get is almost 5mA, cant over pass it ...
0
votes
1answer
35 views

Sticking to high voltage DC Current

I heard that if you come into contact with a high voltage DC current, you will ‘stick’ to it until it is switched off. Why is this and how high does the voltage have to be for someone to ‘stick’ to it?...
1
vote
1answer
26 views

Compensate centrifugal force in accelerometer measurements

I'm working on a project that includes counting the revolutions of a cylinder connected to an engine. This engine runs at a minimum of 5 revolution per second and a maximum of 9 revolution per second. ...
1
vote
1answer
35 views

Paralleling LVPECL outputs?

I have a pretty unusual application here, where I need to drive a fast differential signal fanning out into 8+ 100ohm transmission lines. The unusual part is this: the transmission lines must be ...
0
votes
2answers
53 views

Ultra low leakage capacitor for nano amp current source

I am looking for capacitor type which has very low leakage such as 0.5nA since I am working with a sensor which generates between 0.9nA to 0.55uA. Based on my research Film or foil Capacitor has the ...
1
vote
1answer
33 views

How to reduce ADC noise through PCB routing?

I am routing a PCB board with some through hole IR emitters and transistors and I am trying to figure out placement of ICs/Op-Amps, as well as capacitor placement and route placements to reduce the ...
0
votes
1answer
36 views

Designing a 2-bit ALU

I want to design a 2-bit ALU that does XOR, OR, AND, and addition. With help of Wikipedia: I designed this: However, it's not working. I tried connecting the controllers to S0, S1, S2 but no ...
0
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0answers
31 views

I have purchased a video doorbell requiring three 2600maH batteries

Can I use a 3000maH battery which are more readily available. 3.7 V. Li on rechargeable.
1
vote
1answer
43 views

Vehicle power bus connection techniques

Are there any automotive electrical engineers in here?? I am designing a wiring harness for a vehicle project I am working on. In order to save a LOT of wire, I am looking to implement a 24V power ...
4
votes
4answers
742 views

Does battery voltage actually get lower when connected to a load, or does it just appear to do so?

Sorry if Im wording this question strangely. I am using a 3.7V battery and my microcontroller monitors the voltage and goes to sleep if my battery voltage is too low. The issue is that it reads a ...
1
vote
1answer
48 views

Calculating total resistance between two points (triangle resistor network)

I want to calculate the total resistance between the 2 points: A, B. I've tried using the Delta-Wye method, but I'm not sure how to apply it to my problem since there's 6 resistors and not 3 (usually ...
0
votes
2answers
73 views

Do I need to filter before sending signal to an ADC?

I have an ADC that is capable of a 25kHz sample rate and I have a sensor whose bandwidth is 200kHz that I'd like to hook up to. This is a current sensor. Nyquist tells me that I need to limit the ...
0
votes
0answers
35 views

PCB Grounding Plane Review

I am reviewing a 6 layer board that has analog signals on the left and right side of the board. I have always read that analog circuitry should be grouped together for easy plane segmentation. ...
0
votes
0answers
22 views

Synchronous Generators: The Actual Complex Power

When making calculation involving Synchronous Generators how would I calculate the actual complex power consumed by the load in MVA. I have tried to approach this using phasor diagram which is fine ...
0
votes
0answers
12 views

Calculate PI controller parameters for PLL

Can anybody tell me how can I find Ki Kp values for PI controller for PLL shown in fig? I know that in order to calculate it we need a transfer function of a system H(s). And then we will make the ...
0
votes
0answers
14 views

CAN bit timing register - baud rate

I am trying reverse engineer the CAN Baud rate for a given set of BTR register values that are used on a CAN PCI Card. BTR0 = 0x40 BTR1 = 0x2e I think the frequency is 80MHz. I know there are other ...
0
votes
1answer
14 views

Operating Voltage and Current of solar PV panel connected directly to a battery

Let's assume we have a 60 cell 260W PV panel with the following STC characteristics: Voc= 38.1V Isc=8.98A Vmpp=31.1V Impp=8.37A The panel is exposed to direct sun light and standard conditions are ...
1
vote
1answer
28 views

Ringing issue on I2C FM+ bus between MCU and few sensors - Power supply issue?

I'm experiencing some issues while probing a problematic I2C bus on the oscilloscope. We want to interface several TLV493D-A1B6, with a STM32L4 (we are working as well on STM32F4 and have the same ...
0
votes
1answer
34 views

How to select a DC generator which can generate output at low RPM?

I want to generate an output from wind. The RPM provided to the motor/generator should be kept to a minimum. Also, the force I need to produce the output is around 30 N. How should I select an ...
0
votes
0answers
28 views

Calculating Required Bulk Capacitance

All, Lately I've been thinking more about bulk capacitance in my designs. Previously, I've been careful about part selection and placement for decoupling and filter capacitors during design. Once a ...
0
votes
0answers
9 views

Nucleo F446RE - No SPI response while transmit is working as intended

I'm trying to read some registers of an Atmel AT86RF233 transceiver via SPI with a Nucleo F446RE development board. As stated on the title, whenever I send anything through MOSI, the transceiver doesn'...
0
votes
0answers
66 views

How to measure the angle of a rope on a moving airplane?

I've got a simple rc plane which I want to fly on a tether. The tether is attached to the bottom of the plane like this: I now want to know what the orientation of the rope on the bottom of the plane ...
0
votes
0answers
29 views

Phototransistor Daisy Chain

I'm trying to find a solution to daisy chain together over 200 phototransistors for use with a moving concentrated light source. I need something with fast timing, so I wanted to go with a bunch of op-...
1
vote
0answers
47 views

D Flip Flop Toggle — Q into Hex Inverter into D, Unstable Output, Help

simulate this circuit – Schematic created using CircuitLab I created the above circuit. There is essentially a switch that is normally high. I press a button. Using a NTE4049T hex inverter, ...
0
votes
1answer
32 views

Reading STM32F timer value

I am trying to implement a hardware timer for STM32F and read the value from it. So far, this is my implementation: ...
0
votes
0answers
36 views

Frequency reading using FPGA input pin [on hold]

I have a Lattice FPGA device here and I wan't to generate a sine wave with varying frequency with the device and I want it to send it from an output pin (PIN A) "PIN A is connected to PIN B by using a ...
1
vote
1answer
61 views

Conversion of a signal to digital pulses

The following signal is presented to me, and will vary in freq, but not amplitude from 10Hz up to around 25 KHz. Any ideas for a simple circuit that will convert this into a clean 3V3 square wave for ...
0
votes
1answer
29 views

Dependent sources removal

In thevenin's and norton's theorem why do we dont remove the dependent sources in calculating the thevenin's resistance. And secondly,why do we only use 1 ampere/1 volt source to find the thevenin's ...
-5
votes
1answer
63 views

What happens if i connect same potential to the two side of wire?

In my opinion nothing should happens but correct me if I'm wrong. The reason for asking this foolish question is that I was searching about short circuit and then I came to know that if two wires of ...
0
votes
1answer
23 views

Issues with HUM on DIY audio signal switcher using a relay

I am creating a rack mounted system for toggling multiple guitar pedal effects remotely through a footswitch. The idea is that I create a signal chain starting with the output of a guitar and that ...
0
votes
1answer
33 views

Stepper motor - How to choose a driver

I want to know how can I choose stepper driver, once I have decided on the stepper motor that I wish to use. This is how I understand it: If a motor can draw a current of say 0.5 amps and operates on ...
0
votes
0answers
30 views

Communication Theory - Basic Transmission Errors

I have a question regarding some basic transmission error: My confusion is with the solution to combat errors (transmit each frame 3 times). I would have though that the probability of receiving a ...
0
votes
2answers
30 views

The Relationship of Power and Heat to Length of a Folded Resistor

This question is a follow-up to a previous question of mine (The Relationship of Power and Heat to Length of a Resistor). We make heaters in our lab. They are 1.5 inches long and are made using 0.005-...

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