All Questions
0
votes
0answers
3 views
What is 'valid signal' that router receives to indicate physical status is 'up'?
If the Ethernet interface has a cable connected and is receiving a valid signal, the physical link shows an “up” status and there are no active alarms or defects. If the interface is not connected ...
0
votes
0answers
7 views
Is it possible to transmit Coaxial signal before a cable TV box (wirelessly or otherwise)?
I just moved into an apartment that has no cable jack in the living room. From what I see, I could do one of these things to get signal to my TV:
Request that a new line be run in the home from the ...
0
votes
1answer
12 views
Can a Nordic Semiconductor nRF24L01+ be powered by 5V?
When I look at the nRF24L01+ datasheet, I'm confused by two apparently conflicting details.
"1.9 to 3.6V supply range" (page 1, Key Features)
5.25V maximum input voltage Vi (page 12, "absolute ...
0
votes
1answer
14 views
How to make a dimmer for a 11W CFL?
I have a desk lamp, that uses 11W/827 CFLs (current one is an Osram Dulux S)
The lamp uses a power supply ("Type BL1"), but it seems the transformer acts more like an AC/AC power converter, as it ...
1
vote
2answers
52 views
If I pull the power on my computer and IMMEDIATELY restart it without booting OS, will RAM contents be preserved?
I have DDR3 RAM in my computer. My computer is frozen and I have important unsaved work open. I've already dealt with the problem of how to recover and read the contents of RAM. I just need to be able ...
0
votes
0answers
16 views
Powering a DC car vacuum cleaner with a brushless motor for better performance?
I'm making a self autonomous vacuum cleaning robot for a project and I need a vacuum cleaning mechanism to install on the robot. The problem I'm having is with figuring out how to make the vacuuming ...
1
vote
1answer
14 views
Input interrupt pin associated with TIMER1 on ATmega168
A few days ago I came across the source-code for this ATmega168 based Inductance Meter from Dan's Workshop Blog. Below is the code that I believe sets up an ATmega168 interrupt to measure an external ...
-1
votes
0answers
10 views
Vcore voltage offset, [on hold]
Laptop is Lenovo y510p (with 755m sli and i7).
A week ago, i decided to flash modded bios (a lot more options), everything went well, then i flashed vbios for second gt 755m.
After that, i was looking ...
0
votes
2answers
47 views
Can a computer and its RAM function properly if the temperature of the RAM has been significantly reduced?
This may be in the wrong section so if it is I apologize.
I'm trying to significantly reduce the temperature of my computer's RAM so I can preserve it's contents during a PC reboot. I read about the ...
0
votes
0answers
28 views
Powering circuit and Arduino with single power source
I am trying to power an Arduino Uno as well as my circuit using Li-Ion batteries. They are 2 18650 Lithium Ion batteries (rated at 3.4 V each = 7.4 V total).
I have this battery plugged into the Vin ...
0
votes
3answers
57 views
Simple NOR gate (transistor-level) diagram
My question here is simple:
I cannot understand how the input flows throughout the circuit. I understand the P and N type transistors; I could see why if A and B are both 0, and pass through the ...
1
vote
1answer
31 views
Identify iButton location
A friend asked me for advice regarding a lock system based on iButtons as keys.
There are some doors, and a 1-wire bus along the way, connected to iButton readers and door locks. (let's skip the ...
0
votes
1answer
47 views
FPGA Systems with good Linux support
I am working on a project using a Xylinx FPGA, board produced by Digilent. More precisely, it is the BASYS2. I have been programming the FPGA using Windows 7 as I was unable to install the support ...
3
votes
1answer
61 views
DC Voltage Source - circuit problem
I'm currently trying to build a DC voltage source from an AC source to a school project. The circuit worked fine when it had no voltage regulator, as it was just a transformer + full-wave rectifier + ...
2
votes
1answer
47 views
voltage regulators destroyed — protection diode needed?
I have the following basic circuit:
As I was flipping the button to turn the relay on and off, I noticed sparking from the voltage meter, and it eventually caught fire, releasing the magic smoke ...
0
votes
0answers
40 views
BLDC motor control PCB
I am trying to make a PCB to control a Sensorless Brushless motor. I just wanted to know if it looks right. The IC I am using is a TB6588FG it has a 2.5A peak output current. I want to use it with ...
0
votes
1answer
35 views
What kind of protections are needed to control an AC motor (230 V) using a microcontroller?
I need some guidance with surge-protection of the SSR and also how to safely bring the motor to stop (since it's an RL load, the inductive current has to die out). I found a schematic online, but have ...
0
votes
1answer
46 views
Two arduino unit communication
OK plain and simple I'm not sure to use IR or RF. This is short distance up to maybe 10 ft.
I have an Arduino Uno that I have all set up here. I press a button and it carries out its code. This is ...
0
votes
2answers
47 views
Does the VU meter on audio amplifiers measure the input or output level?
Does the VU meter on commercial audio amplifiers measure the level of the input signal or the level of the amplified signal?
0
votes
3answers
28 views
RJ11 socket in Eagle libraries?
I am trying to add RJ11 (telephone wire) sockets to my PCB on Eagle but am having trouble finding it in the libraries. Is this a standard socket that is included or do I need to install some external ...
2
votes
1answer
43 views
Passing USB signal over short SATA cable and connector
I am working on a prototype device and I will have a daughter-board mounted at an odd angle in a custom enclosure. I need to get a USB signal, and a few extra GPIO type wires, over to the board. I ...
-1
votes
0answers
56 views
A PCB Website Problem [on hold]
I am trying to find a good PCB Board House that is cheap for my PCB board.
I came across a website called Seeed Studio Fusion PCB.
for $20 for a 10 x 10 cm PCB, why not?
I was just wondering if ...
0
votes
1answer
47 views
Contolling current in PWM circuit
I have a PSOC Cypress board which generates a 5V PWM signal to drive a laser diode. The idea is to design a programmable pulse which I could control the on-time period and current in the pulse. The ...
-6
votes
0answers
54 views
3.7V to 40V dc to dc converter [on hold]
I want to make a simple dc to dc converter for converting 3.7V DC to 40V DC. Can anyone got the schematic for this circuit, maximum current flows through the circuit is 100mA?
firstly i need a ...
1
vote
1answer
38 views
Best practice for Lightning/Surge Protection on PCB
What is best practice/recommendation when I want to protect against lighting/surge? More specfically, my application requires passing the following test:
"ANSI/IEEE C62.41---1.2/50 microsecond ...
1
vote
2answers
45 views
Breadboard minimum lead length
What's the minimum lead length for a component in order to reliably connect with solderless breadboard contacts?
Reading specs on cables, relays LEDs, and other components, what should I take as the ...
0
votes
2answers
57 views
Maximum op-amp output current
Im looking to drive an LED, but am not sure if i should use an op-amp or bjt configured as a switch. Is it possible for an op-amp to source roughly 10mA; the current needed to drive an LED in series ...
-2
votes
0answers
33 views
Design a synchronous up/down counter using a JK flip flop [on hold]
I need to design a synchronous up/down counter using a JK flip flop, that must be able to work on a range varying from 0 to 99. It also has to be able to count by 1, by 2 and by 3.
A 7-segment ...
-1
votes
2answers
41 views
Spring Loaded Contacts in vibrating Environment
I need to create a high current (~2A) connection between multiple closely stacked PCBs. Signal connections are made using a 0.5mm pitch, 4mm stack height mezzantine connector with a individual pin ...
13
votes
2answers
759 views
How does USB Type C handle reverse polarity
The new USB Type C connector doesn't have a physical reverse polarity protection anymore. You can plug it in any way you want on both ends, there is also no A and B end anymore, it's all the same.
So ...
0
votes
0answers
20 views
TILT Sensors vibration test
I have to install a tilt sensor in an enviroment with a lot of vibrations. In a device installed in a truck. I want to know what is the vibration limit before we get a false read.
I would work with ...
1
vote
4answers
109 views
KVL loop current direction convention--should be same in all loops?
Do we have to take the same sense of direction for loop current, like clockwise, in each loop when applying KVL to a circuit or can we take different directions in different loops?
If we must take ...
-1
votes
0answers
31 views
How to find replacement slide potentiometers [on hold]
I would like to replace some slide potentiometers in an old Roland synthesizer (Pictured below). It was last produced in the mid 80's so getting a direct replacement is not possible, apart from very ...
0
votes
1answer
45 views
MOSFET controlled DC motor too slow
I want to control a DC motor using a P-channel MOSFET.
I tried the motor with a 5VDC power supply. It works perfectly and speeds up in no time. I measured the current flowing through, it's around ...
2
votes
1answer
135 views
What is the need of Neutral and Phase Metering?
I'm working on a project where I have to implement a metering IC to measure Voltage,
Current and Power on 230v power lines.
I have to use Atmel's 90E24 single phase metering IC. This IC has two ...
0
votes
2answers
54 views
Which is better after rewriting the ROM on a PIC16F? A software reset instruction or a watchdog reset
I am working on a project where the uP can be calibrate at any time. The new calibrated values are stored in the uPs ROM. After the calibration is complete, I have to reset the uP such that the ...
0
votes
1answer
84 views
How can I make a POWER-LED Lamp?
What is the best way to light 10 POWER-LEDs with AC mains (220V)?
(I want to make an LED lamp.)
Here is more info:
I have 10 of these POWER-LEDs:
Product Chip: 40x40 mil
Chip Brand: ...
0
votes
1answer
45 views
Interesting observation on strange behaviour using motors and IR transceiver
I am working on a robot with with the following specs:
Two coin type vibration motors rated at 3V for locomotion
Motors triggered using two darlington transistors (sample schematic shown below)
...
0
votes
0answers
44 views
Arduino turns off when connected to ATtiny85
When I plug my Arduino to my ATtiny85 like this:
As soon as both +5 and GND pins are connected the Arduino lights fade and turn off?
1
vote
1answer
45 views
How to design a SPICE model from data sheet?
I am new to SPICE simulation and I am looking for spice model file of LTC 1065 data sheet can be found here here.
I searched a lot on Google but I could not find ...
-3
votes
1answer
65 views
How to the calculate the value of capacitor placed in series with transformer to avoid flux walking in a buck converter? [on hold]
The dc value of current in primary increases(in -ve direction) as time passes, so I need a capacitor in series with transformer, but don't know what value capacitor should I use.
filter capacitor = ...
-1
votes
0answers
21 views
Tracking and Locate object without camera [on hold]
I would like to track/locate a object without using a camera, i have a quadropter i want to control it using a wand, also need to know distance between wand and quadropter
What would be perfect way to ...
1
vote
2answers
71 views
Lead solder toxicity after cooling?
Now I am sure that most people have read discussions on the possible hazards of handling solder and how your supposed to wash your hands after handling it. My question is, after soldering something, ...
2
votes
1answer
56 views
Lower Voltage LED organ
I am interested in adapting this Jameco kit schematic to my own needs. I have run into an issue though. I am not sure how to lower the voltage requirements. This circuit is built for 12V, I would like ...
1
vote
3answers
67 views
0
votes
0answers
16 views
HSpice optimization of parameters not achieving desired value
I use HSpice.
I have a spice netlist wherein the TPHL and TPLH of my circuit should be less than 3%. I use the Spice optimization parameter as indicated here
...
0
votes
3answers
53 views
Circuit to switch about 5W of 12V using CMOS logic inputs using N-channel MOSFET?
I want to switch some 12 landscape light LEDs, totaling about 5 watts, using MOSFETs.
I thought I had some logic level N-Channel MOSFETs lying around, but apparently not.
What I have is several ...
2
votes
1answer
188 views
Please help me identify two pin locking connector
This is a two pin, locking style connector with "AMP" molded into the front edge; there is also a "P".
Material is nylon or similar and the pins are pushed in from the rear like Molex connectors.
What ...
0
votes
0answers
38 views
Battery backed RAM for access by the OS
I apologize if this is the wrong place to ask this (just let me know where to go, if that's the case).
I want to know if anyone has an idea how to set up battery backed RAM, like in an old S/NES ...
0
votes
2answers
48 views
How to connect 7447 decoder to 7-segment display?
I've connected a 7447 decoder to 7-segment display as shown in figure. When I connect an input, the LEDs doesn't form numbers but they light up randomly.
I just want to know the right way to ...
