0
votes
0answers
13 views

Rs232 to SD card

I need a device that logs data coming from an rs232 port onto an sd card, I know their are arduino shields that could be got to implement this but I am in a hurry and need something ASAP. Does anyone ...
0
votes
0answers
11 views

What is the difference between disturbance and noise for dynamic systems?

In most references from dynamic system theory, the following linear continuous dynamic system is considered. $$\frac{\text{d}x(t)}{\text{d}t}=Ax(t)+Bu(t)+Dd_{1}(t)\quad (1)$$ $$y(t)=Cx(t)+Ed_{2}(t) ...
-1
votes
0answers
19 views

How does adding two Resistors in Series contribute to the sum of its resistances

I would like to know why by adding two resistors in series we would get a sum of it's resistances.I know by Ohm's Law that since $R=\frac {V}{I}$ it's certain that ...
0
votes
0answers
5 views

Units of area parameter in ngspice

Can anyone tell me what are the units of area parameter used in ngspice? Urgent need!
-1
votes
0answers
11 views

Electrical power simulation/analysis software [on hold]

What is the most appropriate software tool for an electrical engineer that wants to play around and understand the intricacies of electrical power generation, transmission and distribution. Required ...
0
votes
2answers
41 views

what frequencies do caps filter?

I've been trying to find out what frequencies get filtered out by which type and capacity capacitors, but cannot find simple rules that say "type X, cap Y filters xxx (k/M)Hz - yyy (k/M)Hz". Yet ...
0
votes
1answer
12 views

Accessing RS232 Rx Tx instead of OTG on stellaris LM4F232H5QD evaluation board

I am asking two related questions here: I can see a program uart_echo for stellaris lm4f232h5qd . What I want is that I need to access this data on teraterminal using PA1 and PA2 pins instead of ...
3
votes
1answer
25 views

Debugging a PIC16F84A interface with a 4N25 optocoupler

I have a PCB board that I'm trying to repair, the principle of this circuit board is to switch an oven relays one at a time only with a constant rest time, and the switching time is predefined by the ...
2
votes
2answers
78 views

Shall I connect inverter with boat GND?

A friend of mine is building a boat. On this boat, he has 12V batteries with a 230V/13A transformer. Recently somebody suggested he should connect the null with the ground. With DC, this is common ...
1
vote
1answer
33 views

How does the power supply noise generated by digital ICs affect the output of regulator?

I have learned that the digital ICs would generate the power noise in the power supply line,however, I am not so clear about how. In my opinion, two contributors: the change of the current would lead ...
0
votes
1answer
23 views

How the Depletion Region is shrinked when Diode is in forward biased?

I would like to know why does the depletion region gets shrinked when a potential is given to a diode(Forward Bias).Is it because we have given a higher voltage than the voltage of the depletion ...
-1
votes
0answers
29 views

Adding more current to circuit [on hold]

I have a high voltage supply (aprox. 20kV) and I would need to increase the current while keeping the voltage. Is there any way you can think of or is it impossible? Thanks.
0
votes
2answers
26 views

Why feedback is needed in PLL FM Demodulator?

I am trying to build FM Demodulator in FPGA. The architecture I am trying to use is PLL-based FM Demodulator like the one below. I searched for the working principle of this demodulator but there is ...
0
votes
0answers
29 views

trouble getting two PICs to communicate via I2C

I'm having a bit of trouble getting two PICs to communicate with each other over an I2C line. Both are 16F886, one sitting in the PIC 28-pin demo board, second one sitting inside a board which I ...
0
votes
0answers
19 views

Use a headphone jack to activate a 'silent' speaker

I am looking for a type of speaker (around the size of a coin) that connects to a smartphone or walkman (for example) which plays silent tones or pulses. Like a miniature speaker that a person can ...
0
votes
1answer
31 views

Why does an Ohmic contact contain non rectifying junction?

I would like to know a simple explanation for the term 'Ohmic Contact'.I looked in wikipedia but I couldn't get what actually it means.I couldn't even get what do you mean by non rectifying ...
0
votes
1answer
21 views

battery charging

I have: -12V 7.2Ah,sealed lead battery,valve regulated -solar panel 12v with 100mA my question is,how long does it take to charge this battery by using this solar panel?
1
vote
0answers
30 views

Function call isn't executed in verilog

Why function call to clogb2 is not being executed in the following code. I don't get any compilation errors but still parameter ...
1
vote
0answers
18 views

Are all connections to my ENC28J60 required?

I'm trying to connect a ENC28J60 module that exposes a SPI interface to my Beaglebone Black. I only have pins 1, 2, 3, 4, 5, 10 connected to my Beaglebone's SPI1 interface and I've used the following ...
0
votes
3answers
44 views

Questions on Operational Amplifiers & Bridge Rectifiers

What I've learned so far from Navy school is that operational amplifiers are used as a substitute for transistor amplifiers and they contain three main circuits: the differential amplifier, common ...
4
votes
3answers
321 views

What is the difference between different types of GND

I would like to know the difference between different types of Grounds like AGND, SGND, Battery Gnd, PGND. Are all the grounds not same? Cant we connect the device to any one of these grounds?
-1
votes
0answers
9 views

anybody help me regarding adding noise source in to tanner tool and measure Static noise margin [on hold]

I have started with tanner 15.1 tool. i couldt find how to add noise sources in to the circuit,to calculate STATIC NOISE MARGIN.
-1
votes
0answers
34 views

synchronous buck converter

!I have designed synchronous buck converter circuit for 48v to 12v conversion. LT regulator IC is used for regulation. Maximum load current is 4A. I am increasing load from 1A to 4A stepwise. I am ...
0
votes
2answers
26 views

Why resistance should be increased for Photoresistor in night for Street Lamps?

I can't get why the resistance for a Photoresistor should be increased at night time as said in Photoresistors. The reason is that I think that to turn on a light it's better not to have a higher ...
0
votes
1answer
21 views

Metex multimeter constantly displaying overload

I have a Metex M-3650CR multimeter and have just replaced the fuse and the fuse it takes is a Fast Blow 2A 250V, now my problem is that the multimeter constantly displays OL (Overload) on the screen ...
0
votes
0answers
21 views

What type of op amp should I use in this thermistor signal conditioner?

I'm designing a thermistor signal conditioner for existing probes. I'm not linearizing in hardware, there is plenty of time to do it in firmware. The thermistor has a resistance of \$\text 7.5\text ...
0
votes
2answers
25 views

STM VCP USB_BUSY?

I am using STM32 VCP firmware, and I am sending data to my PC application If i did not open my serial port in PC, and my firmware keep on sending the data it will cause USB_BUSY to happen, (i think ...
-3
votes
1answer
30 views

Question about IC regulators [on hold]

I have a basic question about IC regulators that I know someone here can answer. Basically if I had an IC 7812 regulator in a circuit that has an input voltage of 14 volts, would the output voltage be ...
0
votes
1answer
22 views

Combining different power sources for hybrid power plants

How can we combine two different power sources? For eg:AC output from a windmill and DC from a panel situated near? Will the combined output be greater?
0
votes
2answers
54 views

Is a capacitive touch screen safe to use?

I was reading about capacitive touch screens. I understood that your hand picks some current flowing on screen. That sounds alarming. Is it safe to use a capacitive touch screen, since it picks small ...
0
votes
0answers
35 views

Decoding ceramic capactior

I've done some searching and found how to decode 3 digit markings, but I'm unsure about 4 digits. I have a ceramic capacitor marked: k2ORu - 9634 I gather that the K is the tolerance, not sure about ...
-1
votes
2answers
40 views

What is meant by pinch-off voltage?

When I read about junction field effect transistors I always get confused about pinch-off voltage in junction field effect transistors. Please explain what this is.
1
vote
2answers
25 views

Finding node voltage of a “Y” resistor network

I am trying to find the voltage at NODE1. My initial approach was to find the current starting from the \$15\$V source then going through \$R_1\$ and \$R_3\$ to ground. Then calculating the current ...
0
votes
0answers
29 views

Simple way to design an electrical bug killer

I've been asked to design a device capable of killing bugs, like roaches. I have looked all over the internet for circuit designs to no avail. I was hoping someone could tell me where I could find a ...
0
votes
1answer
35 views

Microcontroller GPIO input voltage limit

I was looking at a datasheet for a microcontroller and noticed that, under its section for GPIO input voltage (p.14), there is no listed maximum for the high input, only a minimum. Does this indicate ...
0
votes
0answers
32 views

How to switch between two serial data or PWM lines with an Arduino

I am just wondering how is it possible to "switch between" two different serial data or analogue signals using an Arduino. Can I use two transistors to switch between two different PWM or Serial ...
0
votes
0answers
18 views

Cell ID Based Location

certain M2M GSM modules provide an alternative method of finding possition when GPS signals are not available or jammed through Cell Tower IDs. These Cell tower IDs around a device are transmitted ...
1
vote
1answer
27 views

Can this gyrator handle high current and/or high voltage?

Since I first got introduce to the Antoniou Inductor while in university, I've always been amazed at it. I've never built or used one, but I am thinking about using it to simulate an inductor for a ...
0
votes
0answers
34 views

How to read PIC firmware hex file?

I'm trying to understand how MPLABX formats the .hex it produces which I use to program my board for a bootloader I'm trying to make. I've learned that this is a ...
1
vote
0answers
13 views

Cape to ease sensor interface on Beaglebone

Is there a "cape" to make wiring sensors into a Beaglebone easier? Whenever I read some guide for wiring a sensor into the Beaglebone (like this one) it always recommends attaching wires directly to ...
2
votes
2answers
38 views

Solving a Thevenin equivalent circuit

Suppose \$R_{1}\$ and \$R_{2}\$ are replaced by resistors of unknown values which are different from those assumed in part (a). Using a variable external voltage source, a student applies \$+1.5V\$ ...
0
votes
3answers
85 views

What happens if I supply a higher voltage than the rated voltage of my jack?

I want to replace the original jack from my notebook with a new one since it is broken (and I would like to avoid to replace it with the same as the original). The original AC adapter supplies 19V and ...
0
votes
2answers
69 views

Why is the digital out acting as ground on arduino?

I was following LED Light bar project in Arduino Project handbook and I noticed some odd behavior in the Arduino. I accidentally didn't ground the back half of the breadboard (because I didn't ...
1
vote
0answers
35 views

Problems with Infrared circuit on a PCB - Is it the board or schematic?

I am using the toner transfer method to apply my circuit for 6 sets of infrared emitters and collectors connected to an RJ15 cable on a PCB for use with a Raspberry Pi B+ board (connected via IDE ...
1
vote
1answer
21 views

Help needed driving an old PIC programmer from Raspberry Pi GPIO

I have been trying to use a Raspberry Pi's GPIO pins to drive an old PIC programmer board that used to have a parallel port connection before I started messing about with it. You can see from the ...
0
votes
2answers
47 views

Using a microcontroller as a microcode sequencer?

There's this thing called the weird processing unit, or WPU. It's basically an idea of various experimental processors (architectures) that try to be interesting, new, original, extraordinary, ...
1
vote
1answer
22 views

The timing-driven placement phase encountered an error

Could someone explain inexperienced VHDL coder what this error message trying to tell me in simple words? I found a similar question here, but here was no answer to it: ...
2
votes
1answer
51 views

Determine the maximum load of a power supply

I am trying to upcycle an old bit of tech I had lying about. The main part I am looking to recycle is the power supply however I do not have specs of the power supply itself. I have measured an output ...
0
votes
2answers
47 views

Design a 4-bit PISO shift register with 4 DFFs and 3 AND gates

I want to design a 4-bit PISO shift register with 4 DFFs and 3 AND gates. I have gone so far that these two designs can be implemented, but I can't go further minimizing it so as to use 3 AND gates ...
0
votes
1answer
49 views

How can I tell charge only usb cables from usb data cables

Like most computer hobbyists and programmers, I've amassed boxes of usb cables to connect usb, micro usb, and mini usb to chargers, computers, and gadgets. These cables are a mix of phone charger ...

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