# All Questions

116,660 questions
2 views

### SDRAM controller

I am just learning about SDRAM, and i have read that you can use a controller to create dual port access with 2 agents. But the SRAM controller can only take one write request or read request and a ...
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### Z=50 and Xs=0 but SWR is not 1.0:1

I measured an antenna with a VNA and differently to all other cases the SWR isn't low as expected. Here are some screenshot showing this: Similar situation, on the same antenna in the same ...
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### Where did this useful matrix decomposition come from for Nodal Analysis?

Background The equations formed when finding the nodal voltages of a circuit can be expressed using nodal analysis as a square system matrix $\mathbf{S}$ (lets say $m\times m$) which describes ...
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### Bit-Map vs ALOHA protocol

So i have been reading about ALOHA and Bit-Map protocols and i am note sure which is more preferable in the following scenario: 8 stations, numbered 0-7 want to transmit in any given time slot. ...
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### Dynamic voltage divider

im trying to build a esc (electronic speed controller) for three phases brushless motor, i found some intresting circuits but i am trying to build something very easy to do, with mosfet and pc817 and ...
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### KV7RF SMD Datasheet

Can someone identify a 6-Pin IC SMD with the marking code KV7RF? Searching in Google I didn't find anything. Any help on this?
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### CMOS IC Dynamic Edge-Triggered Flip Flop setup and hold time calculation

Before explaining i should point out that i refer to changes of signals in the text as a reference change on which i will calculate these times as 50% change of one signal to 50% change of the other ...
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### An electromagnetic wave incident on a closed loop

Consider the following diagram : Both the electric and magnetic fields will induce a voltage in this circuit. In more details, the component of the electric field that is in the plane of the circuit,...
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### Question about Roland 606 schematic

Hello this is my first post. I have a question regarding the circuit diagram of the Roland 606. I'm currently redrawing the hihat circuit with noise unit. The symbol behind R6, and elsewhere in the ...
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### What is the purpose of the relay in this circuit?

I have tinkered with relays while building small projects with microcontrollers in the past. Usually I use them to switch higher amperage circuits off or on. I recently purchased this horn and this ...
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### BNC cameras over CAT5 to powerline adapters then to DVR?

My apologies if this has been asked before. I have four BNC cameras connected to video baluns then connected to CAT5. Each CAT5 cable from the cameras meet in a junction box and then the video ...
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### Parallel AC Sources

Hello. I am new to electricity. I currently have 3 DC-AC inverter to drive 3 EL Wires(electroluminescent). The input of the inverter will be 12VDC and the output will be 90VAC. I would like to ask ...
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### Upgrading a phone flash memory [on hold]

I've got a Galaxy S4 (GT-i9505) with just 16Gb of memory and I would like to upgrade it to 64 at least. My plan is the following: Find the eMMC module specifications (this should be the correct one, ...
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### Finding speedup when branch prediction is done in instruction decode phase of processor pipeline instead of execute stage

I was solving problems from the exercise of the book "Computer Organization and Design" by Patterson. The problem reads like this: Assume instructions: ...
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### Macbook air logic board 820-3208-A, u6100 Heats up too much and fluctuating voltages

Macbook air mid-2012 won't boot up when I plug the charger light turns to green then orange. The fan spins for 1 second then stops repeats (the cycle will take longer while u6100 heats up) Started ...
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### Creating a logic circuit with 4 lights when one light is on then all other goes off

I have an assignment to crate a logic circuit diagram. The question is as follows: You have four rooms to switch on lights. When you turn on one light then all other lights will be turned off. Design ...
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### Need help with low-frequecy transmitter circuit [on hold]

For this project I am trying to replicate keyfob security system used in modern cars. I need to generate 125khz magnetic field, so that a tag could recognize it and communicate back at higher ...
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### Modifying Transistor Properties in Proteus

I'm trying to simulate a Common Emitter circuit using Proteus. The NPN transistor which I fetched from 'DEVICE' Library has a value of VBE = 0.77V What I want is to adjust this property to 0.6V. When ...
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### Need help on a DIY project [on hold]

I have extracted the microphone circuit from my earphones. I want to be able read frequency values and all from the output of the microphone using an Arduino. How do I do that?
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### Wiring a 7 pin laptop webcam?

I'm trying to connect an old laptop webcam I bought for \$0.93 on eBay to an Arduino Uno microcontroller. Since I currently don't know what all the pins on the webcam are used for, I'm trying to ...
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### AD620 pH probe has a positive voltage offset!

I am a chem eng. but little background in electronics. I'd like to interface a pH probe with an AD620A, the original PCB that came with pH probe was damaged by a current leak in the solution. I made ...
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### Charging a 12v12ah battery

Does this look ok to you? I'm trying to charge a 12v12ah with a 12v battery charger
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### Can I do on-chip debugging on atmega328p with gdb (command line)?

Is there a way of doing on-chip debugging of Arduino Uno (atmega328p) with gdb on the command line? I'm looking for something simplistic and excluding IDE solutions like Eclipse and Atmel Studio. I ...
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### The bootstrap capacitor of IR2110 and VGS of the high side is very low?

I have IR2110 that will drive two n-channel mosfets for syn buck converter with battery as load. I built the circuit and I observe the VGs1 and VGs2 on oscilloscope, which is different. it looks ...
35 views

### Why is the upper part of a Leyden jar terminated with a small sphere?

I often see pictures of Leyden jars that have a small ball attached to the end of the upper connector, was it just a question of aesthetic ?
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### Are things powered by the amount of joules (energy) in a coloumb or by the amount of joules (energy) flowing every second?

My question is in the title, Are components powered by Volts or Joules? I believe it is joules/coloumb, right? Because, if things are powered by Joules/Second then that would mean that the current ...
37 views

### Can the OpAmp be safely removed from the Twin-T notch filter?

This is a very typical (text-book) example of an active Twin-T notch filter with adjustable Q. However, after having posted THIS question, one of the commenters pointed out that there is a design ...
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### Can MCPCBs be used for audio frequency and/or MCU clock frequency applications?

For purely aesthetic reasons1, not for heat dissipation, I am contemplating using MCPCBs for these two applications: Audio frequency circuits, such as a Baby 8 sequencer, Atari Punk console, ...
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### Possibility of effectively under sampling a band pass signal?

For a university project we have been tasked with implementing a digital signal processing system on an STM32 discovery board in which we must model the AM channel to measure and graphically display ...
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### Why datecode is SO IMPORTANT to chip manufacturers?

With the miniaturization of the devices, chip marking has shrunk, not only in size, but also in content. And while the part number got compressed to as little as two letters (or in some cases ...
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### Can anyone tell me what the IC is?

I am working on the re-design of an old board, but due to many reasons, the original design document is incomplete. So I sometimes have to figure out what an IC is. Here is one I couldn't figure out, ...
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### Switching of RS485 differential line. Two sources one output

I'm looking for a solution for my project. I have two signal sources (Primary source and Secondary source) on the RS485 (A/B) differential line. When Primary something goes wrong, the I switch over ...
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### How to connect common anode 7 segment with max 7219

I want t make a digital clock with arduino and rtc 3231. I found some project over internet in which small seven segments are used. I want to use 2.7" large common anode. I dont know how to control ...
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### Design the two-stage operational amplifier shown in the 130nm CMOS process [on hold]

I want to design two-stage amplifier using the required specifications shown in the picture with transistor lengths that are integer multiple of 𝐿min, 𝑊/𝐿 for all transistors that are integer ...
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### KiCad Spice netlist generation fails when using a pulsed voltage source

I'm new to KiCad and I'm trying to simulate a simple circuit: This works fine. The simulation tool works, and if I generate the netlist for spice and can see no problem: Works like a charm. But now ...
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### differential grounded coplanar waveguide, GND-sig-sig-AVDD instead of GND-sig-sig-AVDD

I know we can route microstrips on top of both ground and power planes, but can we use Grounded coplanar in this arrangement? bottom is GND In top layer we have one GND and a PWR. All gaps are 0.15mm ...
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### Field effect transistors

Assume we have a field effect transistor.We connect the source terminal to the anode of a battery and the drain terminal to the cathode of a battery.We connect the gate terminal to cathode of a ...
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### Black lines on laptop appear even laptop is switched off? [on hold]

This definitely doesn't make sense, but the persistent black horizontal lines on my laptop appear even when my laptop is switched off. The normal Color of laptop screen when switched off is a bit ...
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### Can we make the illumination on a bulb higher than the other when two are in series

I have a question: If suppose we have two identical bulbs connected in series with a supply source. Is there any way to illuminate one of the bulbs brighter than the other through any means, except an ...
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### Will a resistor allow the battery to last longer?

3v 25mAh Button Cell battery, a single 3-3.4v 20mA UV LED. If I put a 1/8W 1 ohm resistor in the circuit will the battery last longer?
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### I'm trying to add a 5 minute timer to this circuit so that the it can only on for 5 minutes and turn off

How do I connect a NE555 timer to this circuit so that IR can be on for only 5 minutes ?
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### Why base emitter voltage (Vbe) of BJT is not showing as 0.7v in proteus simulation?

I was just trying to simulate a simple transistor circuit as common emitter in Proteus 8. However the I observe that the base-emitter voltage (Vbe) of the transistor 2N2222 is showing as 1.36v instead ...
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### Thevenin's Theorem: Why is there a $R_{th}$

Consider a linear mess present inside the box, simulate this circuit – Schematic created using CircuitLab If there's a voltage drop $v$ across the load, then why cant we simply replace the ...
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### Trio CS1352 oscilloscope trigger/blanking board photo needed

It may be a very long shot. But is there any one with a Trio CS 1352 who could send me a photo of the trigger/blanking board both sides? My board has some weird jumpers that do not match the schematic ...
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### Convert 240v to 120v for 120V Bulb

I'm having trouble to use my Philips Hue light bulbs, I bought one of their starter kit and later found out that it contained 120v bulbs. Luckily the bridge provided was 120-240v(aka universal). I've ...
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### AC transmission just requires live wire, why is neutral present

If I touch a live wire and stand on the ground I will die because a circuit is completed, so for any load if I connect one end to live and other to ground it should work right, then why is neutral ...
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### HOW TO CONVERT CAPACITOR START MOTOR WINDING TO PERMANENT SPLIT CAPACITOR MOTOR WINDING [on hold]

I have a best brand capacitor start motor (02 Pole, 24 Slots, 01 hp, Double layer Running SWG - 22.5 and 22, Auxiliary swg - 25) and burnt out it's centrifugal switch and all windings. Before ...
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### Can anyone help me with Max Swing? I'm so confused about its property

So max swing is supposed to be when ICQ=VCEQ/Rac right? I understand the fundamental part. But what is Max Swing relation to this: ICQms=min{ICQ,VCEQ/Rac}. I don't understand how it's related to max ...