All Questions

Filter by
Sorted by
Tagged with
0
votes
1answer
3k views

Problem with Xilinx SDK - Failed to Scan JTAG Chain

I am having an issue with running a simple Hello World program on the Trenz TE0720-01 board with a Zync 7020 FPGA. I have been following the tutorial to setup and run the Hello World program given ...
6
votes
3answers
10k views

Played with some lead solder without washing my hands for awhile, should I be concerned?

I was using some lead solder at work, and wasn't aware it was lead solder nor had anyone told me that it can be dangerous. For the most part I was just handling it. This was last week and I don't ...
5
votes
2answers
4k views

What are the Pros/Cons of using an OTP vs a masked chip?

I work for a toy company and to date all of our electronics have used masked chips. This incurs a chip masking charge and a lead time of 45-60 days to mask and manufacture/program the chips. Recently ...
1
vote
1answer
713 views

Reading analog sensor as a microphone signal (via sound card)

I was thinking and studying on how an analog-digital-converter works and just realised that the sound card of every computer-devices is exactly that one. My question is: how can I read an analog ...
1
vote
1answer
752 views

DMM Auto-Polarity / Polarity detection

I have understood how auto-ranging is typically achieved on a digital multimeter, but I'm having trouble finding an example of how (DC) polarity is handled. How does the meter know if a voltage is ...
0
votes
1answer
126 views

Should AC voltage supplied to an external device through a relay be electrically isolated from the main power source of the enclosure?

Given a power supply in an electrical enclosure powered by 120 VAC. An I/O device will trigger a relay with a 24 VDC control. The signal from the I/O device will enable the relay for a set duration. ...
1
vote
0answers
681 views

Antenna array weights and Power input

A big request for clearing this simple doubt. For an application, I am using antenna arrays(say dipoles and array length is 11 elements). Now, this antenna array will have the beamforming vectors ...
1
vote
3answers
183 views

How to detect non magnetic material?

I want to design a paintball counter. I have a metallic or plastic tube through which a paint ball passes. How can I detect that the ball passed? What kind of sensors do I need? I cannot see the ...
0
votes
1answer
1k views

Finding/figuring out pin configuration on undocumented components

I recently purchased an assorted set of LCD/LED displays, and inside there were a set of components which I cannot find a datasheet for upon googling the component number. For instance in the ...
1
vote
2answers
3k views

Bidirectional driving solenoid using H bridge and raspberry pi

I want to drive a old phone ringer solenoid bidirectionally (20 Hz) using raspberry Pi GPIO pins. I am new to electronics, but I thought a H-bridge design would work to do this: The solenoid is 500 \$...
-2
votes
2answers
10k views

Why is the collector voltage must be bigger than the base voltage to operate an npn transistor? [closed]

I'm reading a tutorial on basic transistor operation. It says for an npn transistor to operate such conditions are necessary: VC > VE, by at least a few X 0.1V VB > VE VC > VB We do not exceed ...
0
votes
3answers
179 views

Unplugging home TV saves power? [closed]

I've tried to find recent articles about how to save electricity at home. I remember the most basic instruction was to unplug everything that was not being used at that moment. My problem is that I ...
0
votes
2answers
1k views

How do amps affect RPMs?

I bought a replacement pellet stove auger motor rated at: 120V, 0.51 amp, 1 RPM. (ASIN: B0032D26I6). I installed it into the stove and it works, but the feed rate ...
8
votes
3answers
2k views

Are there any disadvantages using magnetic couplers instead of opto-couplers?

I'm trying to find the disadvantages of using magnetic couplers versus opto couplers (1). I'm deciding which of the two I should use to create a galvanic isolation between two PCB's that are going to ...
0
votes
1answer
55 views

Voltage regulator BD9C401EFJ

I am using the BD9C401EFJ for 9V to 5V conversion (with enable pin pulled high). So - input = 9V and output = 5V. I was just doing some experiments and saw that when I give no input, and I give 5V at ...
0
votes
2answers
219 views

How to light a LED using photo transistors output?

I built a circuit using RPR220 photo sensor to detect the surface displacement caused on a material when external force is applied. I could see the output on a CRO even when there are minute changes ...
0
votes
1answer
603 views

Will a 5V crystal oscillator oscillate with a 3.3V supply?

My question is in the title. I was looking for a component, but I can only find it with 5V. There is no data sheet provided so my question is in general: Will a 5V crystal oscillator oscillate with a ...
3
votes
3answers
980 views

Working with a cathode-based LED seven-segment display

I have recently purchased an Arduino micro and am using it to learn more about electronics and embedded systems. I have a numeric LED display HDSP-H101 with the following circuit diagram, and I am ...
2
votes
1answer
4k views

Does a bridge rectifier care that much for AC frequency?

As I understand it, a bridge rectifier is a set of diodes that play a trick of logic that keeps the polarity positive. So, within the context of a household DC transformer does it matter what the ...
1
vote
1answer
2k views

Correctly measure L7805ACT regulator output

I am trying to measure the output of a L7805ACT voltage regulator (datasheet) with a multimeter, without any additional parts (no caps, etc, just the regulator). I'm using a regulated wall adapter ...
3
votes
1answer
9k views

LIN-communication between two STM32F4 with a standard LIN-transceiver (Hello World)

I have the following circuit connecting two stm32F4 via the SN65HVDA195-Q1 LIN-transciever. simulate this circuit – ...
2
votes
3answers
3k views

Designing for pick and place

I am thinking of using DesignSpark for PCB design and pass the files on for manufacture. If I want to miss out the soldering part and get the full boards made by a pick and place machine, can I use ...
2
votes
2answers
650 views

uC to host Bluetooth module via UART

I am a newbie. I am trying to finish a school project, I need to transmit an analog signal to the computer via Bluetooth. I am using Bluegiga WT12 as the Bluetooth module, and I want to use it with ...
1
vote
0answers
1k views

100kHz active filter design

I am designing a basic 100kHz active bandpass filter using opamps (LF353). I am only interested in receiving the 100kHz frequency (might drift a few kHz) from my input signal. I have used a basic ...
4
votes
4answers
411 views

Electronics protyping and manufacture

I need to design and build an embedded piece of electronics based on a PIC microcontroller. I am assuming the process is: choose chip (PIC16F690) prototype code on PicKit breakout board prototype on ...
0
votes
1answer
4k views

Impulse Response of a series RC filter where the output voltage is taken across the Capacitor

I am finding it difficult to understand the steps to derive the impulse response of a series RC filter where the output voltage is taken across the capacitor, the equation to derive is: h(t)= (1/RC) ...
2
votes
1answer
5k views

Eagle How to flip a symbol?

Eagle 6.5 Schematic I want to be able to flip a logic or op-amp symbol (that is, mirror it about the X axis), but I can't find any UI button or menu item to do that, and it's not mentioned in the ...
0
votes
3answers
163 views

Why Direct Broadcast satellite is interrupted by climatic conditions?

Television signals received through direct satellite service are mostly interrupted by the climatic conditions. But other communication systems that uses satellites are not that much affected. Why is ...
6
votes
1answer
10k views

Permanent magnets near wifi device

Background I have a small circuit that consists of a microcontroller operating on 14Mhz and a wifi module. This circuit is enclosed in a small plastic box. I am considering gluing a few magnets on ...
0
votes
3answers
1k views

555 Timer Astable Multivibrator

Why does the astable mode in 555 timer require two resistors, whereas monostable works with just one resistor ? The cap gets charged through R1 and R2 and gets discharged through R2. But in monostable ...
1
vote
1answer
912 views

why is this oscilloscope so cheap with a 20Gsa/s sampling resolution?

I've looked around this site but I haven't been able to figure out why this oscilloscope seems to have such a high sampling rate "Repetitive mode: 20GSa/S" and be relatively cheap: http://shop1....
1
vote
1answer
241 views

DIY SMD - options for covering exposed vias?

I printed a PCB + got a kapton stencil made for a project I'm working on. One of the components is a BGA chip, and has vias close to the bga pads. The vias on the board don't have solder mask on them, ...
0
votes
2answers
859 views

Differential Driver Maximum Output Voltage Swing

I'm trying to understand how BTL driver on TI's DRV8662 Piezo Haptic Driver (datasheet) works. What I am confused about is how a 200Vpp output signal can be generated from a driver that only has rails ...
14
votes
4answers
15k views

Why is L1 cache faster than L2 cache?

I'm trying to understand why certain CPU cache memories are faster than others. When comparing cache memory to something like main memory, there are differences in memory type (SRAM vs DRAM), and ...
0
votes
1answer
239 views

How to turn a wired dimmer into a wireless one? [closed]

I'm working on a personal project for residential automation. I want to make a wireless Arduino controlled dimmer. I followed this tutorial and I made my dimmer, but it's wired. Below is the circuit ...
1
vote
3answers
5k views

Voltage regulator for DC motor

I'm trying to regulate the voltage of 9 volts battery to DC motor but didn't work. This is my scheme: The original scheme is for led and just wondering why it didn't work for DC motor. Here is the ...
0
votes
1answer
279 views

Dimmer under potential but no load

I have an idea for wiring the lights in a room, which I have run past a few electrician friends, and have received contradictory and unsure answers. There is a large room with two sets of lights - ...
2
votes
3answers
284 views

How to uniquely identify which PCB is plugged in / connected

I am designing a board (Main PCB) into which any one of about 60 slightly different boards (Peripheral PCB) may be connected/plugged-in. The challenge I'm facing is to autonomously identify which of ...
0
votes
2answers
1k views

Identifying an IC with markings: 0270000 DCP1227 0601

I have a chip on one of my boards, and I cannot identify it. I tried differnet variations of search patterns but I cannot find it anywhere. The marking on the chip are in three rows as following: ...
9
votes
3answers
9k views

Why does more bandwidth mean higher bit rate in digital transmission?

I understand that similar questions like this one have been asked before on this site, listed below. However, I am confused about the answers. If I explain what I think I understand, can somebody ...
2
votes
3answers
338 views

Common emitter amplifier

Common emitter amplifier gives an amplified inverted output. So if I fed the inverted output to a speaker, would it sound fine ? If not, how do I get an amplified but non inverted output from a common ...
0
votes
1answer
232 views

Phototransistor responsivity does not match datasheet?

I am making a basic circuit to test the responsivity of a phototransistor. I made a basic circuit using a phototransistor connected to 5V and a 22kOhm resistor. On the other side of the ...
-3
votes
1answer
166 views

Appropriate electronics to use for scoring closest Nerf football air cannon shots? [closed]

Appropriate electronics and sensor technology to use for scoring closest Nerf football air cannon shots? The general concept would be to have a target area marked on the ground around a target device ...
0
votes
2answers
1k views

Debugging a garage door opener circuit with an optocoupler and mosfet

There seem to be many related questions, but I can't quite find the answer I'm looking for. I've got a garage door opener switch. There's 16V across the wires, and when you short them, the garage ...
1
vote
3answers
2k views

Will running a DC motor below stall current damage it?

We have DC motors that power wheels on a car. Because of internal friction, the motors will not actually rotate until they are given 50%+ power. However, they do make some neat noises within this 0-...
0
votes
1answer
193 views

BLDC working driver

I am trying to drive a BLDC motor. I was driving 2 phases and keeping the 3rd phase floating so as to measure the BEMF in it. But, what I find is whatever voltage is applied on the +ve or high side ...
0
votes
2answers
201 views

Voltage sensing

I have a system that needs voltage monitoring. +12 Volt DC -48 Volt DC (-54 Vdc) The ADC chips I can find are limited with input voltage of max 5V. Are there ADCs capable of doing the higher ...
3
votes
2answers
3k views

RF amplifier, why don't two cascaded amplifiers work?

I am currently working on an amplifier circuit for an 8MHz signal (around -40dbm.) The amplifier is based on an IC chip (LM7171 bin). The problem is, the amplifier works perfectly individually (...
0
votes
4answers
6k views

How does a potentiometer work?

A lot of places where I've read explanations about potentiometers either go into so much detail or they're so superficial that I don't understand the actual concept behind it. How would you easily ...
1
vote
1answer
644 views

Prototyping for Bluetooth accelerometer

I'm a software developer looking to prototype an application that requires input from a 3-axis accelerometer, ideally via Bluetooth LE. Current specs on the accelerometer are +/-50G sensing range ...

15 30 50 per page