# All Questions

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### Undersampling of a non periodic pulse signal

I am starting getting familiar with electronics, consider me as a newbie.. I am facing a sampling trouble with my DAQ system. I have a non periodical pulsed signal in the range of 0.3 to 1kHz. The ...
8 views

### book recommendation for undergraduate 1st year

Please can anybody suggest good books for electrical engineering undergraduate 1st and 2nd year(btech 1st and 2nd year)??I am trying to study electrical engineering myself.So book must be oriented in ...
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### How to add PSPICE Model?

Can someone tell me how to add PSPICE Model in PSPICE software. i have downloaded one PSPICE model from "LM239" from texas instrument site, the file they are providing is "LM239.5_1" ...
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### Build Single pole changeover switch from 4066 Single pole, single throw

I am trying to build this circuit which requires two SPCO switch that go between two voltage values but I only have access to 4066N SPST switches. I am not sure if there are better alternative ...
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### Is it possible for an FPGA to “partially” configure?

I have a spartan 6 board that I designed and am having some configuration issues. I'm using SPI flash to program the fpga (e.g. I use jtag to write the flash and the flash then writes the fpga). The ...
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### 7-Segment Decoder outputs/LED display

What would be the difference in using a 7-segment decoder with active-high outputs vs active-low outputs, to driver an LED display?
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### bjt audio amplifier for 8 ohms 25 watts speaker

I have to analyze an amplifier circuit for 8 ohms, 0.25 watts speaker and don't understand how it works. What is the working principle of the components? What configurations are used? In which stage ...
31 views

### How to make a talking calculator?

i am new in electronics. i have a project that aims to create a simple calculator which can talk(whenever you press a button it will say it, so does the answer), is it possible to make a project like ...
19 views

### What is the difference between level triggering and edge triggering?

I am a student who has just stepped into synchronous sequential logic circuits. The books says latches operates with signal levels and clock controls flipflops. But it doesn't make clear what the ...
31 views

### Why does a voltmeter show voltage drop

Consider this circuit. What would I get if I measure over R1? It should be less than 12v, right? But then what volatage is LAMP1 running at? Is it still 12v, or is it the voltage I measured across ...
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### single phase pure sine wave inverter Proteus Model error

I am designing pure sine wave inverter in Proteus. I am getting error as no model is specified for comparator OpAmps LM139/LM239/LM339/LM2901/LM3302 None of the above mentioned comparator are ...
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### How to cycle through outputs ONLY given clock signal?

Purely using digital logic devices (no microcontroller) I was hoping to create something that will cycle through its outputs (only 1 pin high) given only a clock line. Daisy chain flip-flops? I ...
19 views

### Measure capacitance in softwire using Tina/Multisim/other simulators

Is there a way to measure capacitance of a capacitive network as shown below in Tina-TI, Multisim, or other simulators? I tried searching but I couldn't find any way to measure capacitance directly as ...
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### PIC - How to skirt around low maximum ADC input impedance?

Reading a 9V battery on a PIC is nothing new. The most simple and straightforward way is with a voltage divider. I'd like to keep the divider resistances cranked up into the hundreds of kohms so I'm ...
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### The effect of the increase in the number of transistors in a chip on a processor's peformance

everyone. I am doing a research on assessing the degree to which the number of transitors in chips affects the processor's performance in a certain environment. Of what I understand this far, in ...
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### How are differential inputs are setup in a differential amplfifier?

I was struggling to understand what common mode voltage and CMRR is. I think eventually I understand what it is about. Before posing my new question I will briefly write about my drawing. On the ...
33 views

### Reducing Voltage Ripple in a Switching Converter.

I used TI's workbench to design a simple 24 to 12V @ 6A. I have it built in a PCB board, but I started doing some power measurements and notice the output voltage ripple is quite high at loads bigger ...
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### Problems with extending camera module bus/cable?

I like the idea of using a GoPro (or other action camera) as a helmet cam when I'm riding my motorcycle, but I don't like having a big box glued to my forehead. I'm imagining a camera with the camera ...
46 views

### Describe Industrial, commercial and domestic microprocessor applications [on hold]

This is my question for my assignment: Before you accuse me of lack of effort, I have made research on this before posting this. My teacher allows this type of research by asking people whether it is ...
20 views

### Direct-Mapped Cache [duplicate]

I am a bit confused about the tables with direct mapped cache. I've attached picture of the problem, I know some stuff but, I don't know how to determine the size of the tag, offset and set. Can ...
66 views

### Increase GPIO outputs

I'm working on a project in which I need 32 outputs from an MCU that only has 8 free outputs. To accomplish my goal I have the following requirements: I must be able to toggle more than one output ...
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### How to select a power transistor to protect old school automotive ignition and headlamp switches

WAY back in my past I did some serious EE work, but not having used it for nearly 40 years, I'm a little lost on how I do this... I have some 6 and 12 v cars I'm trying to restore and was lucky ...
111 views

### Amplification and -3dB

I have these two circuits: With a 'normal' OPAMP (without capacitors), I do know how to calculate the amplification factor of the circuit ($A=\dfrac{U_{uit}}{U_{in}}$) . But how do I do it with ...
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### How do the windings in a residential transformer create a neutral and why are the hots opposite phase?

Pretty self-explanatory I think; just wondering why neutral "manifests" from the windings and why it "outputs" (for lack of a better word) a negative-phase hot? I guess my perplexity comes from ...
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### protecting a sensor component from high spikes when switching power on

I have an electrical scooter which has a "Hall Effect Sensor" in the handle-bar, measuring the magnetic flux to determine the amount of "gas" or gauge. This sensor tends to burn out quite frequently. ...
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### Is there any micro-controller with ADC > 20 MSPS?

Is there any micro-controller with ADC > 20 MSPS ? and what is the maximum sampling rate in micro-controller in markets ?
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### Component compatibility with Arduino [on hold]

I'm a brand new user of Arduino. I've bought an Arduino Uno microcontroller by itself because it is fairly inexpensive. I didn't buy the kit because I think I can find components at a cheaper price. ...
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### Inverting Summing Amplifier (DC mode) [on hold]

hello everbody . I have a homework. I added picture. I have to make calculation. Can you help me ? How can I do ?
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### Adjustable 555 timer off duty delay

What I want to do is have a circuit with a 555 timer (which is what I have available) that works the opposite of what a monostable circuit should do—well, kind of. What I mean is, on a regular ...
36 views

### Output a Single Clock-length Pulse [on hold]

I'm working on a shift-register-based sequencer that uses 555 timers to generate both the audio and driving clock signal. I need my circuit to output a single pulse when turned on, long enough to ...
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### Flashing LED's and use of switch

Is it possible to wire the LED's in the following way??(shown in the rough diagram of my circuit) I want the LED's flashing alternatively, ie - D1, D3, D5, D7 (A LED's) are powered by just the ...
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### Is it feasible to use fiber optics to increase the detection area of an infrared photodetector array?

I'm working with an infrared emitter/detector system based on an Osram SFH 4545 IR LED collimated through a 40mm dia, 120mm fl lens and a sensor array based on three separate sets of three Vishay TSOP ...
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### Cost-Effective CPLD micropower 1.8V from regulated 3.3V

in my design a ispMACH 4032ZE CPLD (32Macrocells) operates as SPI slave driven by a moderate 8MHz master-clock. The part requires a 1.8V core supply drawing (estimated) tiny 100uA over the full ...
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### Frame memory (SRAM) size for an image

I am now reviewing a paper about hardware implementation and it says by cropping the 128*96-pixels from 160*120-pixels, the size of the frame memory (SRAM) can be reduced to 1/10. I don't get it. ...
48 views

### How we can control the DC motor [on hold]

I have an DME60B motor (DC) with 24V and 490 RPM. I want to turn it on every 8 am Daily and to work for just 5 min. if we want to change the dirction of the motor after 2.5 min to work reverse? what I ...
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### How to force the shutdown of the PIC18 [on hold]

I made a simple project, a "Hello World" test. The LED's light up, but when I turn the power off for the PIC18 they still stay on for a few seconds. I want to turn off the power to the PIC18 with no ...
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### A power electromagnet design for repulsion [on hold]

I have to make an electromagnet for my project. I need to use for repulsion to a permanent magnet. So I need to use its one pole either N or S. I need as powerful as I can make within limitations of ...
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### Calculating maximum power of a unknown resistor

I need to calculate for what value of Rpot, will I get the biggest value of power. This is the electric scheme: The values are: 𝑅1=1kΩ, 𝑅2=250Ω, 𝑈=5V. I have idea how to do it, but I don't know ...
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### DM631 16 channel LED driver

After a bit of advice as reading a datasheet on the DM631, this is a 16 channel constant current LED driver, datasheet can be found here http://www.siti.com.tw/product/spec/LED/DM631.pdf Now the ...
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### PC audio output to microcontroller [on hold]

I want to connect PC audio output (mini jack) to ADC on microcontroller. Do I need to amplify the signal? I only need to distinguish low signal from high signal...
131 views

### Why does a voltmeter read lower across a load than across a supply?

From the Wikipedia article about series and parallel circuits: As an example, consider a very simple circuit consisting of four light bulbs and one 6 V battery. If a wire joins the battery to one ...
81 views

### Why doesnt my light work at night? [on hold]

I got home a few days ago after being gone for a couple months and I noticed one of the lights (CFL) in my kitchen isn't working late at night. If I try to turn it on after around 10:30 PM it almost ...
31 views

### Li-ion BMS restarting after isolation

IN SHORT : Can i power a BMS to check the status of my battery when it is disconnect due to over-voltage or such other reasons by a 12V batery, using jumper cables attached to dc/dc(60-12V) converter, ...
40 views

### Single current source with parallel loads for many RTD sensors

I'm trying to build a circuit that contains multiple 3-wire RTD PT100 sensors (12 of them). I have a microcontroller with plenty of ADC pins so I could potentially measure the RTD and the wire ...
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### Logic Analyzers to go for I2c.? [on hold]

Well i am new to this Logic analyzers but i found that it will be extremely helpful than debugging via scope for my project. I would like your input for the logic analyzers available for Debugging ...
68 views

### Can You Drive Back-To-Back MOSFETs (aka a Solid State Relay) Without Using An Optocoupler?

I was wondering if there was any way of driving back-to-back MOSFETs (with their sources and gates tied together as shown in the following image) without using an optocoupler? The reason is that ...
114 views

### Control two LEDs with two wires and inverter

I have a door sensor (magnetic Hall Effect) that I want to use to build a simple indicator: red LED if closed, green LED if open. Here's the tricky part: I want to run only two wires to those LEDs, ...