All Questions
0
votes
0answers
6 views
Arduino powering an external circuit with higher voltage
First of all, I'm sorry for the newbie question. I'm a software engineer and only a hobbyist in electronics.
I'm trying to power up an external circuit using an Arduino digital pin.
The external ...
-1
votes
0answers
9 views
DDR, PCIe, SAS/SATA Basics
I have no experience with design of high speed interfaces such as DDR4, PCIe, SAS/SATA.
For high speed design fundamentals, I am studying High Speed Black Magic Book by Howard Johnson.
But I am ...
0
votes
0answers
5 views
How to wiring multiple ir photodiode on one arduino pin?
i'd like to use 50 piece of ir photodiode. But, im not sure with it because i want it to be read only on one analog pin of arduino.
My idea is to wire paralel like this on picture. But, im just not ...
1
vote
0answers
5 views
Spoofed solar grid-tied system load management
Thanks for having me in your midst. I am new at this site.
The situation I am designing for is thus: My 5Kw solar array has a micro inverter on each panel. When feeding into the grid, the inverters ...
0
votes
0answers
15 views
voltage drop when probing a NPN transistor's emitter to collector, collector to emitter for PNP
I have some old 2SD1785 and 2SB1258, NPN and PNP transistors that I pulled off of a car audio amplifier. Using this site, I tested the transistors in question and find that they fail on the test on ...
0
votes
2answers
17 views
Voltage Regulator vs Buck Converter
Background: I'm working on a CANBUS and sensor project for an offroad racing truck. Heat, reliability, and RF interference are all big concerns. I'm designing the PCB's and enclosure, so can be very ...
1
vote
1answer
14 views
why the supply voltage of dc motor decreases when the motor load increases?
When I plot the supply voltage of a one-cell LiPo battery during the working period, I found that the supply voltage would drop dramatically when the motor is commanded to speed up.
I think this is ...
0
votes
1answer
6 views
Controlling initial phase of carrier during modulation?
During the process of modulation, any of the three parameters, viz \$\ A_c\$ , \$ω_c\$ and φ, of the carrier wave can be controlled by the message signal where φ is the initial phase.
How is it ...
0
votes
0answers
10 views
One of our single phase motor is showing line current and neutral current, tell me the reason and anything will happen to motor?
One of our single phase motor is showing line current and neutral current, tell me the reason.
0
votes
0answers
10 views
k transfer function
If I'm giving a transfer function
$$T(s) = \frac{G(s)}{1+G(s)H(s)}$$
When calculating the critical gain using the routh hurwitz method and calculating a negative value for k. What does that tell ...
0
votes
0answers
17 views
Using 4-Channel ADC With FPGA
I am using an ADC084S101 4 Channel 8-bit A/D Converter to sample 4 different analog voltages. The ADC is being driven by a Nexys3 FPGA. I am having issues getting the ADC to cycle through all four ...
1
vote
2answers
54 views
What does impedance control on a PCB mean
I understand that when the electrical length is less than 1/10 of the trace length I would have to go in for impedance matching. A PCB impedance is controlled by its stack up. THat is thickness of ...
0
votes
1answer
38 views
Lowering the voltage range of a variable DC bench power supply
I've been shopping for components to build a bench-top DC power supply, much like the one built in Great Scott's video. I'm planning on using a LTC3780, which has an output voltage range around ...
0
votes
2answers
24 views
Comparator help (Lm2903N)
I am using a LM2903N to learn about comparators. I am powering the unit with a 9v battery and connecting to the (+) 5v and the (-) 2.5v. However, when I check the output the resulting voltage is 0v. ...
0
votes
0answers
30 views
How to use LM35 in Proteus Software
I am very new to Proteus. I made a very simple circuit so I could test how a LM35 temperature sensor works.
Why is the voltmeter showing only zero volts with any temperature?
What is wrong?
Edit:
I ...
0
votes
0answers
13 views
Arduino clone ch340g (at328p), MIDI over USB [migrated]
Hi I just bought my first arduino compatible device, and am greatly enjoying it. I finally could not resist the urge after going to an arduino meetup, where someone ...
2
votes
1answer
176 views
RS-232 for approx 1600ft
I am using a cable of approx 1600ft to enable communication between two computers using RS-232(pins 2,3 and 5). On checking the transmitted signal on the oscilloscope, i get the output as below (hex ...
0
votes
0answers
13 views
220v flood sensor setup
I have a question that I think might be easy for someone with more electrical knowledge than me.
What I am looking to do is have a simple water-sensor that either trips a breaker, or cuts off the ...
0
votes
1answer
32 views
555 high amperage charge pump inductorless voltage doubler
There's a few resources out there for indcutorless boost circuits, or charge-pump voltage doublers and triplers.
http://www.electroschematics.com/648/555-voltage-doubler/
But this circuit is only ...
0
votes
0answers
42 views
IC to patch pins arbitrarily?
Is there an IC that will support patching pins together arbitrarily for AC or DC signals going in both directions across any patched pair of pins?
I'm pretty sure it could be done with an FPGA though ...
1
vote
1answer
31 views
Remove pin to close switch
I'm looking for a small fairly rugged normally open switch that closes when a "pin" is removed. It needs to take about 12V It needs to be passive and not require power. Is there such a component?
...
0
votes
0answers
14 views
Amplifier IC - selecting input (Sound Card/Phone jack) and output(Headphones/RCA)
Good evening guys!
I'm trying to figure out the solution to my problem, that I have encountered, but I just can't find anything close.
So, first of all, the situation:
I'm trying to build an 5.1 ...
2
votes
2answers
113 views
Why do people hand wind flyback transformers?
I'm intending on building this circuit, but re-specified for an output of about 150V @ 5mA. Enough to light two neon bulbs from a 12V supply.
Why do flyback transformers such as the Wuther's seem ...
0
votes
0answers
30 views
Protection For This Circuit
This is my theoretical (haven't tested yet) circuit I have designed for a project of mine.
Electrics is a new field for me so please raise flags if my circuit has flaws.
Assuming the circuit is ...
3
votes
0answers
23 views
Why is it that the bandwidth of a patch antenna decreases with it's size?
I typically use a larger (25 mm) patch antenna in GPS/GLONASS receiver circuits. As you probably know, L1 bands for GPS and GLONASS are separated by roughly 25 MHz.
For applications where I want to ...
0
votes
0answers
24 views
Circuit Simulation for a circuit that take a 10KHz input
I can't seem to get the amplitude right can someone help me.
Using the Circuit Wizard circuit simulation software, devise a circuit that
takes as input a 10 kHz square wave of 1 V amplitude and uses ...
0
votes
0answers
16 views
opa569 thermal stress pin issues
I have an OPA569 which i'm using to provide a -1V rail in my system. The power rails to the OPA561 are -1.5V and +2.5V. The op-amp is configured in a non-inverting configurtion, the current limit is ...
7
votes
2answers
39 views
STM32F4 and HAL
So I've been experimenting a while with the STM32F407 (I'm new to ARM) and decided to write a simple app using the HAL libraries since it seems ST has discontinued the Standard Peripherals Libraries.
...
0
votes
0answers
9 views
Initialization of Hitachi-based LCD, using AVRISPMKII, atmel32 micro controller
I am confused by the following, Osc frequency of atmega32, programming frequency of programmer AVRISPMKII and internal frequency of Hitachi LCD. I have used Hitachi Datasheet to determine duration of ...
1
vote
1answer
24 views
ATtiny26l won't work without programmer
I'm running a simple program on an ATtiny26l but if i disconnect my AVRISP MK2 programmer it stops working completely. I'm supplying 5.4v to both VCC and AVCC pins (chcecked voltage).If i reconnect ...
0
votes
0answers
28 views
Circuit draws no power from battery supply, but draws 60 mA from programming header
I am working on a project where I have three different power inputs. The first two are programming headers (for a msp430 and atmega328) and the third is a battery input. All three will power the ...
3
votes
2answers
154 views
Differences Between Smoothed DC & Not Smoothed DC With Respect to Heating
Are there any significant differences with respect to heat generation of a bridge rectified circuit with smoothed DC by use of a capacitor vs one that just uses the raw absolute value of the sine ...
3
votes
1answer
69 views
What are the disadvantages or advantages in using larger SMD resistors and capacitors?
Are there tradeoffs associated with usinng SMD resistors or capacitors larger than a 0805 footprint? As the footprint becomes larger what considerations should be made?
3
votes
2answers
65 views
How are ICs named?
To me, ICs never have names that hint to their uses. For example, this AND gate from TI is named SN74LVC1G08. But that tells me nothing about what it does.
Is there a naming process for ICs? And if ...
0
votes
0answers
20 views
Does IR2104 support PWM wave?
While looking for MOSFET Drivers I locked on to IRS20124s but I could only get IR2104 from the market. I am not sure how to drive my MOSFETs using IR2104.
I have already developed the circuit ...
0
votes
0answers
48 views
Speakers hum whenever I touch the bare speaker connector. Stops when I lift my feet off the ground
Now, it's important to say that these speakers are embedded into a screen, if that makes any difference. (probably doesn't)
When I touch the bare cable, it hums. When I lift my feet off the ground, ...
0
votes
2answers
55 views
4-20mA Error vs Distance Relationship
Is there a relationship between noise error and distance for 4-20mA?
This noise error could be expressed as S/N ratio, percent from full range, dynamic range, noise density, resolution, etc.
Digital ...
0
votes
2answers
34 views
Instrumentation amplifier with frequency-dependent gain?
I have an AD8421 (instrumentation amplifier); it has two pins to connect a resistor Rg that sets the gain --- G = 1 + 9.9k / Rg. For example, a 100 ohms resistor produces a gain G = 1 + (9900 ohms / ...
0
votes
0answers
34 views
Is a 120V smd5050 led strip really 120 volts?
There are many SMD5050-based LED light strips that are referred-to as being "120 volt". But is the strip itself 120V, or is the "AC power cord" that's typically sold with the strips actually ...
0
votes
0answers
37 views
full wave rectifier is not rectifying the wave properly
the following rectifier does not create a wave that is rectified evenly. according to the books this should work when using a centre-tap transformer.
scales : (Y = 10ms/div) & (X = 5V / div)
...
-3
votes
1answer
64 views
What is function of this circuit?
Here is my task (digital electronics)
For circuit below find:
a) In which logic it operates and what is function of this circuit;
b) Max. number of outputs, if circuit is part of chain of same ...
0
votes
0answers
32 views
Which topologies provide the highest input impedance? [on hold]
Hi im novice on this can u help me out. Is it true that common collector offers highes impedance? Talking about transistor as amplification
1
vote
1answer
36 views
Difference between zero-drift and auto-zero op amps?
I am in the process of choosing an op amp for a DAC output buffer. To me, choosing an op amp with the least voltage offset seems like the best choice, naturally leading me to look at zero-drift and ...
-2
votes
0answers
41 views
Bluetooth expert advice noise in the Bluetooth
I'm Working with the Bluetooth module CMD2026_V05 (CW6639E) which is the one it came with the FM module, it work fine but it is also a chirping annoying noise coming from the Bluetooth (while ...
0
votes
0answers
18 views
How to debug a Link Status Down
I have a PHY ethernet connect to another Ethernet device without link connection, when I use an oscilloscope on RX/TX from both devices I can see some signal between then. However, the link status ( ...
0
votes
0answers
36 views
Why does this fan work on the power inverter and not on the main supply power?
This is happening with the pedestal fan of my friend. The fan recently stopped working on main power, but when the main power fails and the backup power inverter kicks in, the fan works.
I know ...
0
votes
0answers
20 views
First try with a TFT Display-ILI9341
i want to use in a project a Display with the ILI9341.
I have the Datasheet just before me but i can´t find how to start...
can me maybe say somebody where the following questions are answered
when i ...
0
votes
1answer
35 views
How large should PCB traces be to control a solenoid?
I'm working on an electronics project that'll regulate and offboard solenoid. The leads controlling the solenoid will need to sustain fairly high levels of current. This is the solenoid I'm working ...
-1
votes
1answer
60 views
3 Amps and 5 volts needed but don't know how to obtain
I am creating a circuit that detects ozone gas. The gas sensor requires a 5 volt supply and at least 3 amps. How do I get these amounts using batteries? I have researched how many amps different ...
0
votes
1answer
18 views
rms measured from STM32F407 is varying slow after changing input
I am using STM32F407 microcontroller with Simulink. After taking the input samples through ADC i convert it to voltage and then measure the rms value using RMS block in DSP system toolbox. I have used ...
