0
votes
0answers
8 views
Asus VW246H Monitor - Hissing with no display
So I started up my Asus VW246H monitor to be confronted with a hissing noise and then the monitor went completely black, opened it up and all the capacitors seem fine, however I found that two chips ...
1
vote
2answers
38 views
Measuring the rotation of a bicycle steering wheel
I would like to mount a bracket onto the head tube of a bike frame to measure the degree of rotation the bike's handlebars have been turned. Ideally, this would be a contactless solution to increase ...
1
vote
1answer
41 views
Value of blown resistor in this simple lead acid charger, Please help if you can
I hope someone can help with this very simple circuit, I have traced from the pcb, my electronics theory has really gone out the window, The circuit shown is from a car battery charger and has a 2 ...
2
votes
2answers
49 views
bjt transistor circuit - finding the resistances
I have been given the followign circuit diagram:
and have been asked to compute \$R_2\$ and \$R_C\$ such that, at the Q-point, the circuit will behave as follows:
\$V_{CE}=5\:\mathrm{V}\$
...
0
votes
2answers
39 views
Understanding basic computer hardware diagram of address decoding circuit
Hi I'm a computer science student doing a computer hardware course and am having trouble understanding this circuit which is supposed to show how control signals at the memory can be generated using ...
2
votes
1answer
32 views
Does RFID interfere with NFC
i have a small question about interference. Do active RFID (860 MHz) interfere with NFC cards (13.56 Mhz) when placed on top of eachother? (NFC above RFID tag for example). Thanks!
0
votes
1answer
18 views
How can I do a frequency sweep when the frequency modulation index is dependent on the amplitude?
I have a question regarding frequency modulation and the modulation index. I know that the modulation index can be given by
$$\beta = \frac{\Delta \omega}{\omega_m}$$
So the value of the ...
0
votes
1answer
49 views
Can someone please help with Electronics transient/capacitor question?
Can someone please help with Electronics transient capacitor question ?
The answer I keep getting is a minus so I think obviously I am wrong.
This question is in this link
from my class notes the ...
0
votes
1answer
36 views
Ultra high bandwidth serial data stream
I have a ultra high bandwidth data stream (USB 2.0 Highspeed), on which I need to add an header for synchronization. This needs to be done, since the datastream needs to be transmitted wireless on a ...
0
votes
1answer
25 views
Is feedback transfer function the same as the transfer function for the whole circuit?
I have a circuit very similar to the inverting band pass filter circuit here:
I was asked a question about the circuit's feedback transfer function. Is this the same as the transfer function for the ...
3
votes
1answer
44 views
Arduino-controlled slot cars - alternative to MOSFETs for speed control?
I'm attempting to control the speed of two slot cars in a set using Arduino.
Each car is controlled by a controller with a variable resistor that looks like this:
They're wired in parallel to ...
1
vote
3answers
55 views
Resistor before voltmeter
Let's say I take my multimeter and measure the voltage across the poles on my battery, I get some reading X volts. I then put a resistor between one terminal and the adjacent probe, this resistor has ...
0
votes
1answer
26 views
Verilog - syntax doubt
In an FPGA code, if I have something like the following:
(* LOC="M18" *) output reg lcd_e;
where lcd_e is an input/output port.
Does this mean that I do not need to create a UCF file ...
-5
votes
0answers
27 views
Arduino board for footprint sensor? [closed]
Would a Arduino board work to develop a footprint sensor for an installation? Which arduino board shall i get for this?
-6
votes
0answers
31 views
Which Arduino board to get to develop a face recognition system? [closed]
Which Arduino board to get to develop a facial recognition system?
1
vote
0answers
33 views
STC3100 capacity remaining calculations
I'm trying to get a better understanding of how to measure battery capacity left. If I understand the STC3100 datasheet correctly, I need to reset the counters when the battery is fully charged. ...
0
votes
3answers
88 views
3-phase explanation
I have been reading about single phase and three phase power. I'm completely confused now.
Can someone please give me a working example of when I would use three phase power instead of single phase ...
0
votes
0answers
22 views
Two PSU in one PC [migrated]
I'm not sure if this is right question for this site, so I apologize if I shouldn't have asked this here.
I have two 400W (labels say that they are 400W, but I think they are much less because they ...
1
vote
2answers
59 views
What are the important considerations when choosing a pass transistor and bias resistor for a buck regulator?
The MC34063 datasheet shows this diagram for a buck configuration with an external (NPN) transistor (in order to be able to handle higher loads than 750mA):
Neither the datasheet nor the ...
5
votes
3answers
150 views
Why do smaller loads require larger inductors in buck regulators?
The MC34063 Application Note lists the equation for calculating minimum inductor size as follows:
$$L_{min} = \frac{V_{in} - V_{sat} - V_{out}}{I_{pk}(switch)} t_{on}$$
But this implies that as ...
1
vote
2answers
75 views
How does this circuit attenuate high frequencies?
I understand that this circuit could be used as a treble control circuit with high frequency gain occuring when R3 is set so a=b (we'll call this k=0), and high frequency attenuation occuring when R3 ...
0
votes
1answer
24 views
STM32 dev kit: Which power pin, APP or EMU?
I need a voltage source for an external peripheral on my STM32 dev kit. (Reference manual available here.) I see from looking at the extension pins that there are two types of power pins: APP and EMU. ...
0
votes
1answer
60 views
What are some cheap 8-10 inch displays? [closed]
I am looking for a display that is 8-10 inches across diagonally, low power, preferably colour and refresh rate isn't an issue. I would want to display text on it, so I need something with a decent ...
0
votes
1answer
30 views
VHDL programming issues…newbie
I'm trying to write a state machine in VHDL that will scan a 4x4 keypad. I want keyP set to 0 at the start and after a Reset. I also want the Col to be set to "1111" at the start and after a Reset.
...
1
vote
3answers
95 views
Random time timer
I'm constructing a simple circuit that beeps a beeper on a given time interval, using a 555 timer. Is there any simple way to randomize the time on the 555 timer between two given intervals, say, any ...
1
vote
1answer
78 views
Electric circuit AC plug to DC Design Help
I'm new to designing electric circuits... but I have a simple project that I really need help on.
All I need is a AC plug source to be connected to a 100 WATT bulb and a 3V motor(motor should only ...
2
votes
1answer
53 views
Ultrasonic Cleaning Solution
I recently found an ultrasonic cleaner while clearing out our warehouse. I'd love to use it to remove flux residue from my prototype boards but I don't exactly know what solution I should use with it ...
0
votes
1answer
44 views
Serial Camera recommendations? [closed]
I have an altera stratix iv FPGA, given to me by my professor to do a project that involves video processing.
The ports I have to work with are RS232 (female), an IDE port and several SATA ports, and ...
-2
votes
0answers
38 views
Good (free) program for designing circuit diagrams? [closed]
Possible Duplicate:
Good Tools for Drawing Schematics
I have 10 relays, 3 motors, a SIEMENS S7-1200 PLC, and a bunch of smaller things that I'd like to make a circuit diagram for. I got the ...
1
vote
2answers
57 views
What does “run a panel” mean in the context of PCB/PCBA fabrication?
A design engineer told me our PCB prototypes would be completed soon and then he would have his assembler "run a panel". Does anyone know what that means?
5
votes
4answers
163 views
How to compute input impedance?
I use a Sallen-Key filter for a project at university and I need to know its input impedance. Is there a way to compute it theoretically ?
Here is my circuit:
1
vote
1answer
77 views
Electrophoretic Displays
I am extremely interested in learning about electrophoretic displays. On their architecture, how they function and also would like to assemble one from the scratch for myself and see how it works (I ...
4
votes
2answers
156 views
Should you place traces at right angles through a via?
I understand that right angle pcb traces should be avoided because it can cause problems during manufacturing.
But what about right angle through a via? Will this have any negative effects?
I ...
1
vote
2answers
95 views
Making a notch filter fo 500Hz frequency
I am trying to make a notch filter which blocks 500Hz, I beleive it should look like the circuit below. Any idea how can I find the proper values to make it not to pass 500Hz? I tried to give random ...
1
vote
0answers
24 views
BLDC Regenrative ESC and LiPo
I am currently working on a project where I want to implement a Brushless dc motor (like the Turnigy C2226 - 1800kv) to run in-hub of an RC car. I need this entire project to be as lightweight as ...
2
votes
2answers
64 views
Buck Regulator Running From Car Battery Stability Problems
I'm running this regulator off of a ~12V car battery. I've set it up almost identically to the 'typical application' schematic and layout that the datasheet suggests to generate a 5 V output, ...
1
vote
0answers
38 views
FFC/FPC that locks directly onto PCB?
Does anyone have any recommendations for an FFC/FPC connector that locks the flex cable contacts directly to pads on the PCB rather than the connector bed?
I am trying to get a VERY low inductance ...
1
vote
1answer
40 views
names for SMT ribbon cable socket types
whats the name of the type of ribbon cable socket used in laptops? or what would I look under to find them on a site like farnell?
Its some thing like a D-Sub connect to system, except the plug is ...
0
votes
3answers
66 views
BJT biasing and operating points
What exactly is the definition of an operating point in the context of Bipolar junction transistors. What is their physical significance? I was going through few books on electronics and found that a ...
2
votes
2answers
102 views
Why can't a feedback network use a capacitor? [closed]
Possible Duplicate:
Basic Frequency Control Circuit
In the following schematic, why can't R4 be taken away and the feedback network pass output feedback through C2 and R2?
-1
votes
1answer
87 views
Types of amplifier - what is the difference?
What is the difference between an open loop amplifier and a voltage follower (unity gain buffer)?
4
votes
2answers
76 views
Maximum cable length for 3.3V UART signals
I would like to avoid using RS-232 converters between two microcontrollers on two different boards. For various reasons, only UARTs are supported, e.g. no SPI or I2C, and I will be using CAT5E cable ...
-1
votes
1answer
65 views
Karnaugh Mapping Assignment [closed]
Design a combinational circuit with 3 inputs x, y and z and 3 outputs A, B, and C. When the binary input is 0, 1, 2, or 3. The binary output is one greater than the input. When the binary input is 4, ...
5
votes
6answers
284 views
Why is feedback required in op-amp circuits?
I understand that, in order for an op-amp to function correctly, a DC feedback loop from the output to either the inverting or the non-inverting input (depending on the external circuitry) is ...
-2
votes
1answer
55 views
hardware component for playing mp3 [closed]
I have a software + hardware project that I need some help with. I built an algorithm that finds certain patterns in audio, the system works great, I reproduce the audio using a simple mp3 player + ...
2
votes
2answers
89 views
How to test RF (1GHz) PCBs?
I have a number of RF PCBs. I would like to test these PCBs, so can someone guide me as to how to test these PCBs. The list of the PCBs that I want to test is mentioned below.
4th order Butterworth ...
1
vote
1answer
44 views
PIC analog to digital converter to measure more than one battery voltage (with different grounds)
I'm trying to build a circuit that can scale down several lipo batteries (5 cell) up to 22V max to be safe to either 3.3V or 5V for measuring with a PIC microcontroller using the analog to digital ...
1
vote
3answers
104 views
How does a chip interpret different opcodes?
I have learnt in school about opcodes and how it works with the ALU to add numbers and such, now is my question how the computer is able to understand this, because it is codes and the computer needs ...
-4
votes
1answer
61 views
What is the most monetarily cost effective way to buy computing power? [closed]
Assuming unlimited space and power what is the cheapest way to buy off the shelf processing power (GPUs, microprocessors, etc.)?
I am looking into doing a fluid dynamics simulation, with an ...
1
vote
1answer
39 views
TL16C550 UART doesn't transmit, baudout is permanently high
I've got a TL16C550CIFN UART wired up to a MC68000 softcore in an FPGA.
The UART seems to be working correctly in that I can write the registers (I'm toggling OUT1 and OUT2 etc) but the baudout pin ...
