All Questions
1
vote
1answer
23 views
Device to switch a 220VAC/40A resistive load
I need to switch a 220VAC/40A resistive load. I only need on/off switching, no phase control. I would like to avoid mechanical (moving parts) components if at all possible because of reliability ...
0
votes
0answers
17 views
Maximum Ohms for IR LED and transistor
I bought a cheap IR extender and I'm trying to use the small sticky cases to control my TV using a Raspberry Pi.
The extender has two "heads" with a small IR LED in it and they were connected to the ...
0
votes
0answers
10 views
Can I charge litium ion battrey 3.7v with 5v usb cable? [on hold]
I buy clipper with battrey 3.7v (from usa).
The charger comes with is :
Input 120v ~60hz 150mA
Output 4.2v 600mA
I'm not living in usa so need to charge it with 220v socket.
Can I charger it ...
0
votes
1answer
11 views
Assembling JST PH connectors
I assembled a few JST PHR-4 connectors with wires (manually crimped SPH-002T-P0.5S crimp terminals with AWG24 wires and inserted it into the PHR-4 connector housing). When I tried to join connector ...
1
vote
2answers
37 views
Best way to lower a signal voltage
I'm interacting with a computer and the return high (1) is at 12V but I need it to ~5V. What is the best way to lower the voltage without affecting the signal (serial) ? I already thought of a voltage ...
4
votes
1answer
23 views
How do I debug red signals in ModelSIM?
I have to design a state machine using only NAND gates for the combinatorial part and D flip flops for the sequential logic. Everything should run at a clock of 1ghz/53.
Now before you assault me ...
-1
votes
1answer
21 views
8.4 V battery pack for DSLR coupler
I am planning to make a battery pack, by using rechargable batteries, that i can use to power my DC-coupler for my DSLR camera.
The DC-coupler is normally powered with an 8.4V AC/DC power supply.
As ...
0
votes
1answer
15 views
how to simulate 4 bit ring counter using max+plus II
I'm newbie with max+plus II and digital modelling world just want to simulate a simple ring counter https://www.dropbox.com/s/47tlv3g7o9zi8gb/all.jpg the ring counter's initial value must set to 1 ...
0
votes
1answer
36 views
PCB Identification - Many relays, 2 LM2596s, and other power-related components
I'm looking at a board lying around in my home and have no idea what it is, expect for the fact that it appears to be power-related. There's a transformer in the corner, many relays, 2 LM2596s, and a ...
0
votes
2answers
56 views
Why can I put a resistor at either lead of this LED and still see its effects? [duplicate]
Just to add a little bit of context to the question, I am using an Arduino Uno and a breadboard.
I have a 5V power source running to the positive (longer) lead of an LED (rated at about 2v and 20mA). ...
0
votes
0answers
8 views
can't get arduino fio with bluetooth be to pair
I can't get my arduino fio with bluetooth bee paired with my mac. I got my application working with a different board (arduino uno) and USB connection. The code I'm uploading to my arduino fio is ...
0
votes
0answers
16 views
Matching subwoofer with amplifier [on hold]
I have 1 kenwood w3013 1200 watts sub woofer. Which amplifier should I buy for it ?
0
votes
2answers
41 views
How do phones charge their battery at seemingly any rate with no issues? 500mA or 1A or 1.2A depending on the charger?
If most use some sort of li-ion battery, and those batteries like to be charged in CCCV format how can my phone charge just fine at 5V, 500mA or 5V, 1A or 5V, 1.2A just fine (actual current delivered, ...
1
vote
1answer
27 views
Single-Supply Transimpedance amp?
So, I'm curious if there is a way to make a single-supply transimpedance amplifier op-amp circuit that uses a single supply. One thing that is important to me here is that it does not use a dc offset. ...
2
votes
2answers
95 views
ATmega328P running on CR2032 has issues with timing/sleep code as voltage depreciates over time
I have an ATmega328P running at 16 Mhz on CR2032 with a few sensors and radio for about a week now. It started out at 3+ Volts and is currently measuring at 2.96 Volts. At present, I am not using ...
0
votes
1answer
21 views
Sonar sensor constantly gives similar output
I have a somewhat general question about sonar sensors.
I have three "SN-HRLV-EZ1" (maxsonar) sonar sensors and I use them to do obstacle avoidance. After a few crashes two of the sonars always show ...
1
vote
2answers
50 views
What is the best way to power both my 5v 16 x 16 Neopixel matrix and the 9v Arduino that drives it? [on hold]
I have 4 Adafruit 8x8 Neopixel matrices interconnected to form a 16 x 16 matrix driven by an Arduino Mega. Right now I am using two different power sources to power the matrix and the microcontroller. ...
1
vote
0answers
8 views
How does UBI determine a NAND flash block is bad?
I understand that if a block erase fails it can be marked as bad. If a page write fails immediately it can also be marked bad. I have a board that shows "read disturb" and/or "program disturb" errors ...
0
votes
2answers
42 views
Proff of that in RLC circuit in series where AC source works in resonant frequency the sum energy of the inductor and capacitor is zero at all time
can anyone help me please prove the statement that:
In RLC circuit in series where AC voltage source works in resonant frequency the sum energy of the inductor and capacitor is zero at all time.
I ...
0
votes
3answers
86 views
How do you achieve an efficiency of more than 1 bit per Hertz?
I believe this is also known as spectral efficiency - apparently it's possible for us to transmit more than one bit per Hertz.
But to my layman mind I imagine a Hertz being only capable of ...
-3
votes
0answers
36 views
How to write a file in VeriLog? [on hold]
I am writing an Image rotation final project
Description:
The image file is read
The image is processed
The resulting The image file is written
I am doing the first two steps but the last step is ...
1
vote
1answer
29 views
Multiple traces for single connection in Eagle
I'm manually routing a power distribution network in Eagle, and am trying to follow the IC vendor's recommendation to attach vias to the power plane both left and right of the bypass capacitor's ...
0
votes
6answers
57 views
How do I figure out the exact voltage and current needed for a part?
Whenever I look for parts in my local electronics store, I come across parts(e.g a speaker), that have just a power rating stated(e.g 2W).
While I know how to calculate power,voltage, resistance etc, ...
-3
votes
0answers
35 views
Working of a field focusing element
I saw a setup of wireless power transfer and it used something called "magnetic field focusing element". Its placed in between the transmitter and receiver coil to increase the flow of flux into ...
6
votes
5answers
710 views
Extract 5W low voltage power from 3000W high voltage source
I have a solarpanel array that generates 600V, 5A (3kW). I want to create a small electronic unit to measure the DC current and voltage and transmit this wireless. For this I have an electronic board ...
-1
votes
1answer
45 views
Static in earphones when scrolling with mouse [on hold]
Why do I sometimes hear faint static in my headphones when I scroll with my mouse? I have noticed this on multiple(4) computers, with Windows 7 and 8. Does anybody else notice this? It happens when I ...
6
votes
3answers
610 views
How does a Crystal work?
Specifically, a 2pin and 4pin quartz crystal oscillator.
What I know: current is applied and the crystal oscillates in order to provide an oscillating signal.
What I want to know: How does the ...
2
votes
1answer
49 views
Can oscillators be made from a single supply?
Oscillators such as a Wein-bridge sinusoid or a square wave Schmitt trigger oscillator. Is it possible to bias these so they oscillate above 0V?
0
votes
1answer
41 views
Modifying a chip on a bought voltage measurer
I have bought a battery checker for my RC LiPo battery packs. The battery checker can measure and alarm at low voltages between 2.7 and 3.8 volts, however with LiPo batteries, the interesting range is ...
6
votes
2answers
124 views
Why does reactive power affect voltage?
Why does reactive power influence the voltage? Suppose you have a (weak) power system with a large reactive load. If you suddenly disconnect the load, you would experience a peak in the voltage.
Is ...
0
votes
1answer
49 views
Proper resistor for simple circuit
I have a potentially stupid question, but I have no idea how to handle the problem. I want to use 9V battery with a diode that requires 5V. So I need a resistor. How do I find the resistance if (as ...
-1
votes
1answer
44 views
Improper functioning of Timer1 in pic18
I'm using pic18f controller and i am supposed to get a delay of 1 sec.I'm using an external crystal of 16mhz and this is the configuration bits that i have used in it.I have configured the timer1 and ...
0
votes
1answer
17 views
what is the dependence of Current through inductor in parallel RLC CIRCUIT with a AC source at resonance frequency
Consider the parallel RLC circuit
simulate this circuit – Schematic created using CircuitLab
Assuming $$ C,L> 0$$
$$ I(t) = U(t)*cos(t/(LC)^(0.5)) $$
So, we have a source that starts ...
1
vote
2answers
49 views
How one uses level sensor?
I have bought a level sensor. I cannot find any documentation except this on the linked page. How do I use it with Arduino or anything else?
0
votes
0answers
38 views
Capacitor value in suspected low pass RC sub-circuit
I've got the sub-circuit in the image below which originates from a larger circuit setup we are currently investigating.
I suspect it might be a low pass RC based filter and I'm trying to figure out ...
2
votes
1answer
25 views
Triac motor controller
I have build a circuit with the purpose of driving a ~1000VA AC motor. The motor controller fires a triac only at zero crossings. The circuit is as follows:
simulate this circuit – ...
4
votes
2answers
281 views
Why are MOSFETs used for VLSI IC fabrication instead of JFETs?
Why are MOSFETs used for VLSI IC fabrication instead of JFETs? What are some reasons the use of JFETs is not common?
0
votes
2answers
29 views
How to get 12v 5amps battery setup for LED strip
I'm building an LED lightbox but I really want to avoid using a power supply/cable so I'm trying to figure out a way to do it with batteries.
The strip I'm using is ...
0
votes
2answers
30 views
Differential Pressure sensing circuit
I'm trying to understand a differential pressure sensing circuit that I have.
Have attached rough design sketch as well.
Sensor used is "10 INCH-D1-MV-MINI" by Allsensors. Output span is 20mV for 10" ...
0
votes
1answer
27 views
Find NMOS transistor with specific ron [on hold]
I'm searching for a specific NMOS transistor that has ron= from 8Ohm to 12Ohm when he has applied Vgs= from 3.3V to 3.9V and the Id that flows trough it is 60mA to 90mA.
Pleas if any who noes one ...
0
votes
1answer
24 views
Finding batteries to make a stable 12 V battery-power supply
I want to make a stable 12 V battery-power supply for RPi and LED matrix. Schematic is something like:
...
0
votes
3answers
105 views
How is Ground in a Power Supply made?
I've been using different power supplies for 6 years. But, I'm unable to understand how we make ground in a Power supply? Or from where does this ground come? Or from where does this reference ground ...
0
votes
2answers
50 views
What influences capacitor maximum current handling?
In this answer it is said that the maximum capacitor current handling is "largely a mater of losses", what I can understand that is a factor for maximum dissipation.
So, what is the thermal ...
0
votes
1answer
23 views
Resonant frequency in parallel
I'm currently learning about resonant frequency and harmonics under ac theory in tafe, and I've read a few things about resonant frequency in parallel, and it seems as if impedance at resonant ...
0
votes
0answers
18 views
Help in choosing an electrical motor
As a dad to a newborn girl that calms down and falls asleep only when rocked vigorously in her crib or pram, I thought that it could be a nice idea to automate that process. I have a couple of ideas ...
0
votes
2answers
403 views
What makes an incandescent light bulb run out?
What is or are, the most likely and common ways - the weak links in the chain (including I assume poor electricity wiring / configured housing) - that cause a traditional incandescent light bulb to ...
-1
votes
0answers
14 views
Imported .brd to Altium is completely black
I've recently imported an .brd file (allegro PCB) to Altium, and it worked, but when i want to open the imported project on other PC, the PCB files are completely black. I've tried changing layers, ...
0
votes
2answers
22 views
connecting an enamled headphone jack to a bread board
I am trying to make an audio amplifier on a bread board. I have a headphone jack with enamled wire and I need to connect it to the breadboard using conductive wire. I have been unsuccessful, does ...
0
votes
1answer
19 views
Can TPS3700 undervoltage overvoltage monitoring IC drive relay directly?
I am new to electronic circuit design. My current project is to monitor biasing voltage for under/ over voltage using IC from TI: TPS3700. If any of the under/over voltage occurs I will need it to ...
0
votes
1answer
46 views
Understanding single sideband modulation and demodulation
I know this question has been asked a lot of times before but i cannot really understand how is the message transmitted in single sideband modulation.
See the following images taken from the book ...
