Something put into a system or expended in its operation to achieve output or a result

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1answer
90 views

Controlling a single phase AC fan with a 0-10V DC input

I have a fan motor which is a permanent split phase single phase capacitor motor: http://uk.rs-online.com/web/p/axial-fans/2781543/ I currently control this fan's speed with the following ...
10
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4answers
535 views

Is this clamping voltage divider for a high-impedance input a good, robust design?

I have an AC input as follows: Can range from ±10V to at least ±500V continuously. Runs from roughly 1 Hz to 1 kHz. Needs > 100 kΩ of impedance on it, otherwise its amplitude changes. May ...
2
votes
1answer
87 views

Why is my pull-up resistor not working?

here's my schematic. I've got this circuit hooked up to those pins. Q1 is P-channel MOSFET (AO3401A), I've also got an ATmega328P not pictured, and POWER_BUTTON is connected to PC4 of the ...
0
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1answer
33 views

Comparator input below V-

I am searching for a way to use a comparator with possible negative voltage on its inputs. My thoughts and attempts so far: Op amps and comparators with V+, V- and GND: the circuit utilizes a ...
0
votes
1answer
31 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 ...
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0answers
32 views

Select from multiple power sources to a device

I hope this is an easy one, it sounds simple to me, yet confusing. I have a bluetooth speaker driver that has a barrel jack DC input which takes 8V to 24V, I'd like to wire up a switch to allow me to ...
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2answers
49 views

Impulse Response of a circuit

The following periodic function, \$x(t)\$, is the input to a linear, time-invariant system The impulse response of this system is $$h(t) = \frac{\sin t}{t} $$ which I converted to ...
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2answers
34 views

Impulse Response of a LTI system

The input to a L.T.I. circuit is \$x(t) = 6\cos(t)\cos(3t)\$, and the impulse response of the circuit is $$h(t) = \frac{\sin(3t)}{3t}$$ Obtain an explicit expression for the output y(t) as a function ...
0
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1answer
52 views

Programmatically switch betwean ground, power, signal for input port

I have this idea on creating a Atmel-based board with PS/2 connector for testing of old keyboards. So I'm looking for a way to assign 5V, ground or signal to each pin of the connector after board ...
1
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4answers
127 views

How to make a Karnaugh Map with “don't care” inputs?

I know that don't cares mean that it doesn't matter whether it is a 0 or a 1 and when don't cares are just outputs I can kind of understand how they work. But I am having a really hard time ...
0
votes
1answer
54 views

PWM input specs of Hobbywing Quicrun WP-1040 ESC

What are the controlling input specifications of a Hobbywing Quicrun WP-1040 Electronic Speed Controller (ESC) for brushed motors? I assume it should use the standard PWM with 1 kHz frequency as ...
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2answers
62 views

Common mode voltage elimination at differential pair receiver

Can you please explain to me how is common mode voltage of differential pairs is eliminated at receiver side? For example, if on RS422/485 bus there is more different transceivers (drivers and ...
0
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2answers
55 views

Updating outputs in PLCs

For all PLC manufacturers, is Mass I/O copying the choice for updating outputs? I found that there is another possible method: the continuous I/O updating. Can anyone tell me what is the reason for ...
0
votes
4answers
124 views

How to increase number of micro-controller inputs?

I have relatively little experience with electronics, but do have a basic understanding. I am attempting to build a measuring device, which will measure 100 points in 0.1 seconds. These will all ...
0
votes
1answer
53 views

How to understand rail to rail input circuit?

I watched an input circuit for ground rail as follows, Why do I have to place a current source here? If I place a resistor instead, there will still be current flowing in emitter-base direction for ...
0
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2answers
70 views

Same pin as output and input

In the 7447 BCD to 7-segment decoder chip, pin 4 is BI'/RBO'. That pin acts both as input and output. I would like to understand how exactly the internal circuitry works to make this possible. On page ...
0
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2answers
50 views

Is Input Offset Voltage perfectly proportional to output

Is Input Offset Voltage perfectly proportional to output in an opamp? Such that if one where to enter 0V differential to the +V and -V inputs, the output would be A*Input_Offset_V. Also, when using ...
0
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1answer
61 views

class AB amplifier input resistances

I was wondering if you could help me out, what would be the effect of changing R1 & R2. I have looked online, but mustn't be searching in the right place! My guess is that you would adjust them to ...
0
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2answers
43 views

Detect position of walkers along a path using IR transceivers

I am working on a project that the position of people walking along a path needs to be known. I'm a hobbyist so I don't know what options I may have. I want to use IR sender and receivers to ...
0
votes
1answer
52 views

input current vs output current

My old/new laptop adapter specs as given below. I understand the output current for new is 4.5A which is OK when compared to old which provides 3.25A load since it can provide more load. However, ...
0
votes
1answer
38 views

reduce sensitivity of digital input

I have a battery (3v coin cell) powered device with a digital input to a microcontroller. There is a pull down on the input of 10k. It is connected to a switch outdoors which, when off, could have a ...
2
votes
4answers
107 views

Unstable input to trigger LED after 10-15 seconds (12 V)

I have a small excavator that, when fuel levels get low, the warning light flashes irregularly (due to movement of the machine) until it stays on as fuel level gets really low. It's very annoying and ...
4
votes
4answers
391 views

How does a logic gate behave with an input changing faster than its propagation delay?

I am attempting to create a simple logic circuit simulator. I am having a hard time figuring out how does a logic gate behave with an input changing faster than its propagation delay. When attempting ...
1
vote
1answer
51 views

FPGA input pin internal floating

I am now occouring a FPGA pin damage problem. One of my pin is hardware connected to a 1.8V signal that will be switched on/off occasionally, while the port is not connected to any other logic gate ...
0
votes
1answer
93 views

How to have 256 bit input for micro-controllers like Arduino?

I want to read 256 digital input, each of which is driven by a switch. I don't need to read state of all 256 switches more than 5 times a second (or may be even less). Multiple switches can be ON and ...
0
votes
1answer
76 views

Connecting Multiple Sensors

I have 4 pairs of "LED + LDR" sensor. I need to be able to switch each of them on/off independently and take reading from the LDRs. To connect all of them to the microcontroller board, I would need 4 ...
1
vote
1answer
52 views

Error in making pins input in PIC32

I am trying to make some pins act as input in PIC32MX795F512L. I am doing like this ...
0
votes
1answer
71 views

Arduino - Weird behavior reading speaker level input

I'm trying to detect when speaker starts playing audio, my speaker is connected with a 10uF 50v in series with the positive (red) cable coming out of my receiver, and negative to ground. Speaker (+) ...
1
vote
1answer
124 views

Power In does not Equal Power Out

I have the following setup: 480V, 200A service fed into PWM Drive, Drive output going to 1000kVA step up transformer (8.4 ratio) feeding a 2380V/53A 3phase induction motor. The motor is UNLOADED. ...
0
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2answers
74 views

Difference between an Analogue multiplexer vs ADC chip with lots of channels

Advantages and Disadvantages of Analogue Multiplexer vs a ADC chip. For having more analogue inputs on micro-controller. Thx
1
vote
1answer
91 views

How calculate the input offset current effect on measured voltage?

Here is the data-sheet: http://www.mccdaq.com/pdfs/manuals/PCI-DAS6034-35-36.pdf A data-acquisition board's differential amplifier measures a constant voltage across a resistor R1 shown in the Figure ...
-2
votes
1answer
68 views

Altera FPGA Pinout help [closed]

I recently bought an Altera FPGA Cyclone II board off of ebay, it says BAIXUN on the LCD display. It didnt come with any documentation. I'm trying to program the FPGA board but I have no idea what pin ...
0
votes
1answer
187 views

Amplifing guitar signal in order to connect it to ADC

I would like to connect an electric guitar to ADC (or MCU internal ADC input) in order to process signal digitally. I'm not sure right now which MCU or ADC I'm going to use, nevertheless I believe ...
0
votes
1answer
70 views

Why can some products take 110v 60hz and also 240v 50hz? [closed]

Most modern chargers can go into any output across the world. I believe this is because of low powered "Switch mode" technology it uses rather than transformers, like they used to. To go from high AC ...
0
votes
1answer
216 views

Bits are high on disabled pins(STM32)

For some reason I have many bits with value 1, even if they are supposed to be turned off. I tried to debug it with some LEDs and Keil uVision debugger. uC is STM32F103 The situation is: I have 2 pins ...
1
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0answers
129 views

Duplicate MIPI CSI2 camera (one camera, two receivers)

I would like to feed two processors with the same MIPI CSI2 camera. I cannot afford to have one of the processors to play the role of proxy to the other. Though I searched hard, I'm not aware of any ...
1
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1answer
290 views

Latched outputs on 8255A

I am studying about the 8255A PPI. In Mode 0 of it, it says that the outputs are latched and inputs are not latched. What exactly does it mean?
2
votes
1answer
139 views

Handling large number of inputs in PIC microcontroller

I am interfacing PIC32 MCU with 24 inputs and UART. When any inputs comes, this data is transferred to PC via uart. I am using multiple if condition like ...
0
votes
3answers
162 views

Is there a way to count the number of high inputs with logic gates?

I have \$2^n\$ inputs \$a_{0}, a_{1} .. a_{2^n}\$, these can be either hich or low, and \$n\$ outputs \$z_{0}, z_{1} .. z_{n}\$, these give out a binary number of how many of the inputs are high. Is ...
-1
votes
1answer
80 views

How to connect a headset as a microphone, and speakers at the same time with only one cable [closed]

So, I recently bought a headset from Tritton, named "Kama", as I got home I noticed a unusual problem... The audio input and output are in the same cable. I would really want to use this as both, but ...
0
votes
3answers
116 views

Help to build a circuit to trigger event only after input signal changes from “1” to “0”

I'd like to build a kind of logic as shown in the picture ,but I can't do it and I really appreciate if someone can help on that. Basically what I'd like to achieve is that when the input signal ...
2
votes
2answers
86 views

Input and UART error in PIC32

I have a PIC32 starter kit and I am making a program such that when I apply input 1, MCU will send this data to my PC using UART and ...
0
votes
2answers
152 views

Arduino digital input - Read voltage slightly higher then 5V - a power efficient solution [duplicate]

I need my Arduino to detect the state changes in a device - (ON or OFF). In order do do this, I have to check the voltage between two points on the PCB of the device. When the device is OFF, the ...
0
votes
1answer
151 views

How to connect input and output on Bistable Multivibrator

I built the circuit below on my breadboard. I've checked every connection and it doesn't work. The thing I didn't know how to do was connecting the output (a LED) and the input. (a button) I did ...
2
votes
1answer
76 views

Input output voltage problem in PIC32 starter kit & IO expansion board

I have a PIC32 Ethernet Starter kit and IO expansion board. I have a made a simple input output program in which if ...
1
vote
1answer
56 views

Is this a safe design for an input at a 74HCT165

I'm new to designing my own circuits so please be kind and tell me if I'm right with my thoughts or if I have errors in it. Thanks! The purpose of the 12V is to compensate the resistance of long ...
0
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3answers
142 views

What happens to voltage source if I take out both volt and current with separate circuit using diodes and then combine both separate circuits?

I have 3.8V and 1.2Ah battery. I will use a step up circuit that gives 5v and 200mA output using 2v in (from my battery). Then I will use blocking diode to take voltage only(5v) and I don't need ...
1
vote
1answer
364 views

How not to waste power with digital inputs?

I am trying to make simple gates with n-MOSFETS, yet I'm not sure how to actually do physical gate inputs correctly. At first, I tried this (a single-pole, single-throw switch from +5V to gate). ...
1
vote
2answers
433 views

Quick question about aux cable DIY

I've been planning to make an aux cable for my BMW 3-series, because the original costs 80€... So I've read a couple of DIY and I've found this So I've ordered the cable, capacitors, and the ...
1
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2answers
112 views

Input range of operation amplifier

Lets have a look at the following circuit: (Input waveform is sinusoidal and Vpp would be ~32V) The input waveform should represent an AC Source from a ...