0
votes
0answers
5 views

op-amp based audio amplifier not working

I have a problem with audio amplifier I am trying to build. Given my ignorance I cannot figure out how to fix the issue. There is absolutely no sound on the output. This is what I have assemblied: ...
0
votes
0answers
7 views

Altium Leaves Board Border Outline on Assembly Notes Layer

No matter what, Altium leaves a border of the board on my cover page when I try to generate an assembly document. I only have two layers: Assembly cover notes and Assembly notes tops. Neither of which ...
0
votes
0answers
15 views

Crystal Oscillator output voltages and power

I have built the crystal oscillator stage to the Pixie 2, a Hartley oscillator, with a 9 volt voltage source. I measured the output with my VOM set to AC 30 volts. It read almost 30 volts. That is ...
0
votes
1answer
25 views

Can a proximity sensor read through fabric?

I am trying to build an arduino project with the following requirements: Proximity sensors detect human presence and its distance The sensors are hidden behind fabric Range has to be 1-3 meters or ...
0
votes
0answers
14 views

Linear vs. Audio Taper for RC Network

I'm building a distortion pedal and I was wondering which tapers to use for which potentiometers in the tone control section. I normally design my own circuits, but I'm going by someone else's ...
1
vote
2answers
51 views

Why is a binary system used instead of decimal system when interpreting voltages? [duplicate]

In physical computing, binary is used to perform calculations. Typically, 1 corresponds to high voltage (3V-5V), and 0 corresponds to low voltage (0V-2V). Perhaps it is not feasible due to the ...
0
votes
3answers
43 views

Electronic Length Measurement

I need to measure small distances (from 0-5mm) with precision upto 3 decimal places (like a micrometer). What sort of sensor can I use for this? This is for measuring terminal heights. I understand ...
2
votes
1answer
47 views

Where can I find a stable AC to DC switching power supply?

I've purchased multiple 3V switching power regulators form Amazon and they all have spikes in the ripple. Here's an O-scope capture: The spikes increase frequency depending on the load. Are these ...
0
votes
1answer
45 views

Weird problems with LCD (HD44780 compatible)

I've been trying to interface with a HD44780 compatible display (16x2) for quite a few hours now, but have run into some weird behavior problems which I can't solve. My setup: I'm using the LCD in ...
0
votes
2answers
33 views

Raspberry Pi + Microcontroller for commuting audio input and output

I am new in electronics and I'm working on a project with Raspberry Pi that I need help. I want to make a board that allows to commute 4 audio inputs (TV, MP3, DVD, FM web) in 4 audio outputs ...
1
vote
1answer
25 views

PWM or switch port programmatically for Servo

Is there a huge difference between using a PWM and switching a port through a program (like using switch) for operating Servos? For smooth movement is PWM necessary or switching using a program will ...
1
vote
1answer
30 views

How do I enable/disable a running 555 astable oscillator with a control signal?

I am going to control a fan using PWM signal. PWM is generated by a 555 IC. The duty cycle rate of the PWM is controlled by a PTC thermistor. And an NTC thermistor decides when to turn on and off the ...
1
vote
4answers
163 views

Which circuit to use to automatically turn off the backlight of a GLCD after 30s?

Have you ever seen smart phones automatically turn their screens off after a short time to save the power? I want to do it on the back light of my GLCD (ks108sed). Descriptions: Back light will ...
-1
votes
0answers
34 views

Understanding the tradeoffs between UHF and Bluetooth in Remote Keyless Entry

I've been doing some research on remote keyless entry, and I am wondering why Smart Keys and the like use UHF in key fobs, instead of Bluetooth Low Energy? Is it because BLE has only been a round a ...
0
votes
0answers
9 views

Xilinx Video Timing Controller freezes processor

I'm trying to acquire video from an image sensor using a ZedBoard with Vivado 2014.2 and I used an existing (working) video passthrough project of mine and simply added in a debayer (color filter ...
2
votes
2answers
43 views

Understanding load cell and instrumentation amplifier

I want to build a weight scale with 0.1 gram resolution. But I have some problems in my initial stage. I am using a load cell with sensitivity of 1mV/V and excitation voltage of 3 V. With no ...
1
vote
2answers
33 views

Calculating discharge time of 12V LED light powered by AA batteries

I just want to check up my assumption on power consumption of six 12V LED lights in parallel connection. So I powered it by 6 AA (E91 energizer) batteries. The LED's ideal forward current is 80 mA ...
11
votes
6answers
624 views

How should I use a multimeter to determine which AA batteries to keep and which to toss?

I have a bag of about 50 non-rechargeable AA batteries (1.5 V) that I have collected over the years. I bought a multimeter recently and would like to know the best way to test these batteries to ...
0
votes
3answers
73 views

How can you calculate base voltage of a transistor when there are biasing resistor and a resistor between 2 input terminal

I just get to know about transistor a little. Here is my question As you can see that here the transistor is configured to be an amplifier in common emitter mode. R1 here is the bias resistor. What ...
4
votes
4answers
149 views

What are the square holes for in most electronic project boxes?

I'm new to the electronic scene and lately I been purchasing a lot of project boxes for the stuff I make, I've noticed in about 75% of the boxes I purchase they come with small square shaped holes on ...
0
votes
0answers
16 views

Do anyone have verilog code of median image filter? [on hold]

I am on initial stage of verilog coding of image filter. How we read image using verilog? Any kind of suggestion will be helpful.
0
votes
1answer
23 views

If interpoles are used in DC motors and reduced the entire armature flux then how is torque induced in the motor?

If interpoles are used in DC motors and reduced the entire armature flux then how is torque induced in the motor?
2
votes
1answer
51 views

Remove DC offset and rectify

I'm using ACS712 hall effect current sensor to detect presence of current in the power line of a remote device. I don't need exact current value but rather just want to know if it's above certain ...
0
votes
0answers
41 views

8-Bit data encoding using Hamming code

I am using Pic18f45k80 controller for my project. I am in need of storing 60V lead acid battery's voltage level in internal EEPROM. I am using Hamming code as Error correction algorithm. My data is ...
0
votes
1answer
51 views

Trying to understand vhdl led blinking code

I have a led blinking code for MachXO2 breakout board written in VHDL. Actually I am new to VHDL. I am not able to understand the meaning of these lines: ...
1
vote
3answers
97 views

Pull up resistor

I'm software, not hardware, and would ask our electronics guy, but he's away on a site visit. Someone on StackOverflow suggested I repost this here. I get the basic idea of a pull up resistor as ...
3
votes
4answers
81 views

Why do most PWM LED displays and backlights operate at a relatively low frequency?

All around me are a bunch of electronics: digital clocks, my laptop, a refrigerator, a dimmable flashlight, and more. What they all have is perceptible flickering of their displays due to PWM, ...
0
votes
1answer
37 views

Help compare my results to the maximum power transfer theorem and explain using algorithms

So below is an image of the relationship between efficiency of a circuit and the resistance of the load, as you can see the maximum efficiency occurs when the two resistances are equal. here is a ...
3
votes
1answer
41 views

Inductor value given in OHM/Amp

I've been trying to figure out the inductance in Henries from a schematic of a Rabbit Microprocessor development board, however, instead of finding an inductance value over the components in question, ...
0
votes
0answers
26 views

android accelerometer frequency [on hold]

I am working on project that including android mobile device accelerometer. In my product I need to get samples in rate of at list 1000Hz but after doing a little research I found that I can't achieve ...
-4
votes
0answers
25 views

how can i study PLC in a free mode with any simulator or not [on hold]

i am an intermidiater in embedded system, any one can say how can i understand and practice in PLC? Now i am living in kerala, India. any institutions have a good background in your experiance please ...
-1
votes
0answers
29 views

Powerworld Alternative? [on hold]

I want to do some analysis with network models. My network data comes in .raw files, has multiple circuits, and is large; I want to be able to compute TLRs/LODFs/PTDFs, preferably algorithmically ...
0
votes
1answer
76 views

Don't understand spec sheet

I'm planning to buy a photo-interrupter, and I had a look at the spec sheet, but I didn't see much on the current/voltage of the device. I was thinking that it could run on 20mA, but I am confused ...
0
votes
1answer
58 views

PIC microcontroller and different EEPROM sizes?

What is the significance of how big the EEPROM is for a microcontroller. I'm trying to select another PIC (first one I chose - PIC16LF1827 - didn't have enough RAM for the application I needed it for) ...
0
votes
0answers
17 views

Wiring Leds In Parallel? [migrated]

Hi I have 4 120 v 20 watt leds. I want to put them over my desk. They are the Lusa Lighting Model #33000 (If you want to see the pdf). They come with plugs so you canplug them in seperately. I want 1 ...
0
votes
0answers
15 views

Beaglebone Black running Debian, does device tree overlay act as an api? [migrated]

This maybe more of a Linux specific question but... I've been reading many tutorials and it seems that you can use JavaScript, Python, and C++ to write code for the Beaglebone Black(BBB). It looks ...
-5
votes
0answers
33 views

How 'lost carrier' and 'no carrier' detected? [on hold]

By using command 'show interface ', one of the line of the command's result is like below. 0 lost carrier, 0 no carrier How they are detected?
2
votes
0answers
59 views

Individually dimming 64 high-power LEDs of 350mA with a low current LED PWM driver

First of all, I have to admit that my knowledge on electrical stuff is in a low level. I need an advice to select or design a circuit to provide constant current for high power LEDs that will be ...
1
vote
1answer
48 views

STM32F1 troubles with a timer

I'm having some troubles with setting up a 1 second timer on STM32F103 mcu. I have set Timer 2 to have a prescaler of 1099 and a period of 65514, so I'm expecting to have a 1 second interrupt rate: ...
0
votes
0answers
47 views

Wireless Mesh Sensor network comparisons [on hold]

From your past experiences (don't need a whitepaper): Could you guys compare Zigbee, Z-Wave and 6LowPan? Please also include information about compatibility with regular internet protocols. I think ...
0
votes
1answer
114 views

What parameters to look at when comparing capacitors of same value but different package size

I'm looking at a capacitor that will be used as an output cap on a buck regulator. Looking at what I think is the same exact cap from TDK (10uF, 16V, X5R) but in an 0603 and an 0805 package. Beyond ...
2
votes
1answer
135 views

Optimizing LED Project

I'm working on a project the will use 20 white 3mm LEDs that I harvested from a 154 LED Christmas light string. I plan to use a 9 volt battery for power. What's the optimal wiring schematic? Series, ...
0
votes
1answer
43 views

Measure 208v single phase with Current Transformer

I have a single phase 208v circuit that I want to measure the amps on. What is the proper way to measure the amps? This is for a connection with 2 hots and a ground wire, no neutral coming from a ...
0
votes
4answers
109 views

Wire for project with 9 volt battery

I'm working on a project that powers 20 LEDs with a 9 volt battery. What gauge of wire should I use? A couple of LEDs are in series with a 180 ohm resistor. Then each pair are in parallel.
-2
votes
1answer
54 views

Prototype for 8x8 RGB LED display [on hold]

I am planning to build a small, very low-resolution, 8x8 RGB LED display, which would be able to display a video (some kind of colorful visualization, lo-res) or a picture from PC via DVI or HDMI ...
1
vote
1answer
94 views

PIC18 electric connection loose

I'm using a PIC 18F4550 to blink an LED in a breadboard through a resistor. I think the circuit is correct because a simulation with Proteus works fine. The physical circuit doesn't work unless I ...
2
votes
2answers
70 views

Interfacing incompletely documented logic signal where resistor affects output voltage level

So I've got this marginally documented 12V logic signal from something I have to regard as a black box that I'd like to interface to a pi or arduino (i.e. c 3V). I have 3 lines - 0V, +12V and signal ...
0
votes
1answer
23 views

SIM908 POST Request

I want to send a couple of variables to a webpage in my server over the SIM908. Does anyone know how do send such data over POST protocol? I was able to complete the task using GET but currently ...
0
votes
2answers
67 views

Maximum number of reads in flash

I am using an AT45DB081E 8-Mbit flash from Adesto (formerly from Atmel). I am storing 7-byte data records and keep the location of the newest record stored in the last page of flash. This value is ...
0
votes
1answer
38 views

Controller area network voltages

The CAN bus has CAN-High and CAN-Low lines. Normally, in the recessive state the voltages are each 2.5 V and in the dominant state the CAN-High line goes to 3.5 V and the CAN-Low line goes ...

15 30 50 per page