Questions tagged [input]

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

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1answer
100 views

Can I use an RC network somehow to allow reading of initial values from jumpers into a micro controller?

I completed a microcontroller project but I want to add a feature where when it starts up, it can read a 4-bit value defined by on-board jumpers (jumper closed = logic low, jumper open = logic high ...
0
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1answer
190 views

How to connect from a +/- 15v audio circuit to single powered amplifier

I built a 3 WAY CROSSOVER (ELLIOT SOUND CIRCUIT) with +/- 15v supply. I have found small class D amplifier for Mid AND high amplifiers. They are single sided power. Can I simply couple the input ...
1
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4answers
655 views

Tube Guitar amp Input Transformer Removal

for a few weeks I've been trying to remove the input transformer from my little 60's Magnatone amp. The schematic indicates a 1:3 step up input transformer, but from reading elsewhere on the internet ...
0
votes
1answer
794 views

Proper biasing to virtual ground with TLE2426

I've made simple circuit - it attenuates the signal 10 times, bare bones voltage divider: simulate this circuit – Schematic created using CircuitLab Now I want to bias the signal to half of my ...
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1answer
442 views

How to add a 32-bit input in Quartus 2

Can you help me to add a multiple pins input in Quartus 2? If there is not a default one, how can I add it by MegaWizard Plug-in Manager? Thanks!
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2answers
411 views

Protect Pycom Lopy from 12V input signal

I am in the process of building a water meter counter using a Pycom Lopy. The Lopy operates at 3.3v but my input sensor which is a metal detector (K1208065) uses 12V. Someone else has already build ...
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3answers
861 views

Three different schemes to amplify audio input, which one is correct?

I'm building an audio amplifier (prototype) with display and MCU (Arduino Nano), see photo below (not finished ;-) ). On the display I want to show some VU-meters of the input but there are ...
1
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0answers
128 views

Bell button as input

I got a simple bell system from elcom. It works with 12V AC. When I measure the voltage at the switch it is 1V when not pressed. When I measure the switch sides to the power input of the bell system ...
3
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4answers
15k views

3 input XNOR gate operation

For 3 input XOR gate and XNOR gate, by solving the equations I got the result as in the picture. So according to the solution the outputs of the 3 input XOR and XNOR gates are same. This solution ...
-2
votes
1answer
447 views

How does rated horsepower compare with input power?

If I look at the motor specs, it gives a rated HP: 1 HP @ 2740 RPM & 42.6 Amp, 1.91 ft-lb. My end goal is to get torque as a function of time, but I cannot remove it from the machine. I can ...
1
vote
1answer
240 views

Combine 1 connector for in and output

To simplify the outside design as much as possible (keeping it simple to use and less expensive) I would like to use just one small 2-pin connector both as output to drive an external led and as 5V ...
9
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2answers
4k views

PCB “Touch” Button

Is it possible to use a PCB pad as a button? I think of using it to switch on a curcuit that is only supposed to be enabled, when the user holds it in its hands. As inspiration, I used the pads that ...
3
votes
2answers
382 views

Define input current of Op-Amp

I haven't done and studies in Op-Amp category yet but I watched a (trusted) video on Youtube and one thing is not quite logical as the next sentence: "No current flows in or out of the inputs of ...
1
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1answer
175 views

Industrial level input protection

Take for example a Siemens S7 24V digital input. I read a couple of articles and also questions on SE and it seems there should be (maybe integrated, maybe as a discrete part): optocoupler to ...
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2answers
114 views

Texas Instruments Schmitt Trigger inputs

Hi I want to use the TPIC6C595 in some project. Because my application needs to be very noise insensitive I am wondering whether the shift register uses Schmitt Trigger inputs for G, SRCK, RCK, CLR, ...
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3answers
68 views

Will the IC mess up if the inputs that don't affect the output are disconnected?

Here's the situation. I'm trying to incorporate ANY decoder in the HC family to decode two bits. I'm also using the eagle autorouter. I decided to go with 74HC139 since its a dual decoder and the pin ...
0
votes
1answer
565 views

turn level-based input to edge-triggered input [duplicate]

I'm trying to figure out with the most minimal part count how to convert an input of a digital IC to an edge-triggered input. I am using the 82C55 IC and the input on it I want to make negative edge-...
3
votes
2answers
163 views

PWM controlled Input Voltage/Current regulated Converter (for solar panel)

(newbie question) Briefly: In a converter (let's say DC-DC), I want to dictate a voltage to the output of solar panel, on the fly. As I look around online, for example in some IEEE papers, Buck or ...
10
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5answers
6k views

Considerations when using internal pull-up/down resistors

I am working with STM32 micro-controllers. These micro-controllers have the option to set the input pin as pull up or pull down: Earlier I used to give external pull up or pull down resistor wherever ...
0
votes
2answers
823 views

PLC Input Buffer/Driver

First post! Please bear with me... I am an electrical tech and EE student with no design experience. This is the first circuit I've been asked to design. I have been given the task to take the input ...
0
votes
1answer
136 views

Function of a component in a Ethernet Board

I want to know what is the component located next to the Ethernet input for. I guess it is for filtering, but I'd like to know it's name and it's main function if possible. Here it is the board: The ...
2
votes
2answers
2k views

Measuring 230V from Raspberry Pi

I have a problem: We use some Raspberry Pi to manage some contactor with a simple relay. This relay can manage one or more three-phase switches, so basically it is linked at least to three contactors. ...
1
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3answers
108 views

Simulating keyboard input onto ribbon?

I'm considering starting a project that would require me to transfer data onto a keyboard ribbon in such a way that it mimics typing. Would it be possible to do this through wires connected to the ...
0
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2answers
90 views

Is it possible to accept analog input, digital input and provide digital output and analog out on a single MCU Pin?

This is based on my previous question here: How to accept switched GND or switched Positive on a 3v3 MCU input But I want to go further so I think it is best to ask a new question. My device is much ...
12
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3answers
2k views

Can unconnected inputs make an IC get warm?

I am using an ATF16V8 PLD for some simple glue logic. While testing it on a prototyping board, I noticed that it gets warm to the touch almost immediately. I checked that no outputs were short ...
2
votes
1answer
314 views

MOSFET driver input resistor

In datasheet for MOSFET driver ZXGD3003E6TA is following typical application circuit: What should be the value of circled resistor? I did not find any reference in documentation. Datasheet link: ...
2
votes
2answers
325 views

Arduino analog input pin impacts incoming signal

I have a hall sensor throttle which outputs a signal that scales between 0.8 and 3.6V. The problem is that when I connect it to an Arduino MEGA2560 analog input pin, the voltage never goes over 2.3V, ...
0
votes
2answers
9k views

4 to 1 multi-bit multiplexer implementation [Q]

We are tasked with creating a 4 to 1 multiplexer with 4-bit inputs. I believe I fully understand how to create a 4 to 1 1-bit multiplexer, but I completely do not understand what the 'input' side and '...
-2
votes
1answer
62 views

I can understand the function of [closed]

In the circuit shown below I can understand the function of the two output diodes 1030 (using for clamping voltage over 3.3 V or reverse voltage), and also I know the function of the two input ...
0
votes
3answers
430 views

ATMega input buffer

What happens if a AVR ATMega controller is doing something else when a input arrives on one of the serial ports? Does it has some sort of input buffering? I was thinking of using ATMega328 or simalar ...
1
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6answers
2k views

How can I build a simple USB signalling device?

I would like to construct a simple device that plugs into a USB port and sends the computer a signal (i.e just a 1) when a user presses the button or switch etc. I ...
3
votes
2answers
706 views

Clamping diodes or TVS

When should be clamping diodes preferred over one-directional TVS for input sanitation? Consider only digital inputs, not power lines. Clamping diodes seem to be recommended so I worry I might be ...
1
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2answers
504 views

Detect 220Vac signal on Microcontroller

I'm developing a module and the control switch may be at long distances. Considering I have the 127 or 220Vac input, I want to use that for switch signal. I believe is better, instead of making a ...
2
votes
3answers
1k views

impedance matching for Guitar input

What is the main difference between mic input and a guitar input? is it only the source impedance seen in the input of the amplifier? I am designing one pre-amplifier in which i need to input both ...
1
vote
0answers
517 views

P-MOSFET based automatic power selector

I have designed the attached power selector circuit, it has a 12V input and a 15V input, and should prioritize the later. It operates in three different scenarios: 1- 12V source R76+R79 divider ...
0
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0answers
125 views

PIC18 port b interrupt on change is very sensitive

I am running a stepper motor with my PIC18F46K80 microcontroller. This microcontroller offer me the port b interrupt on change feature which basically generates an interrupt if the state the port b ...
0
votes
1answer
308 views

What's the difference between all of these video inputs? [closed]

Over the years and with the large variety of hardware I've dealt with I've used quite a few of different video inputs and outputs. While I usually have no issue just plugging cables into devices, I ...
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2answers
455 views

12V Signal -> Relay -> Voltage Regulator -> Arduino mega analogue input. Will this work?

I have a system that sometimes generates a 12V signal to a DPDT relay coil, which switches on a 12V connection through the relay pins that can be used as a boolean signal to the arduino. I plan to do ...
0
votes
1answer
170 views

Connecting two different microcontroller outputs together to drive a single device?

I am interfacing with an existing product. This product uses a PIC16F54 uC and is ultimately driving a solenoid. This device is a black box to me and I have no input into the software running on the ...
6
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3answers
769 views

How CRT allows use of ligh-guns or pens etc?

While reading about CRT on Wikipedia, an information (CRT Allows the use of light guns/pens; https://en.wikipedia.org/wiki/Cathode_ray_tube#Advantages_and_disadvantages) suddenly triggered a a vast ...
1
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2answers
180 views

ATMega32u4 output power to input without external resistor?

I am new to electronics and have a SparkFun Pro Micro clone with an ATMEGA microcontroller. I wanted to know if I could set one pin to be an output that sends power to another pin that I have set as ...
5
votes
2answers
685 views

Diode Clamp failing with LDO Circuit

I'm back with yet another mystery. Summary question: Why would an input to a voltage clamped circuit de-stabilize and or elevate that voltage clamp's upper rail? How do you properly clamp voltage ...
1
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1answer
181 views

Read a common digital output from multiple digital inputs

I'd like to read a single digital output with two separate systems, each of which has a digital input. Both systems have a common ground. In principle, since the digital output is low-impedance and ...
0
votes
5answers
195 views

How to check 4 inputs and set flag in Microcontroller

I have a PIC MCU and have 4 input pins. I need to check the status of inputs and set the value of flag. Like if input 1 is active, then value of flag should be 1, if input 1 and input 2 are activated ...
2
votes
2answers
3k views

How to make clamping circuit to clamp exactly at 3.3 volts

I am building a circuit that attenuates the signal and sends it to 3.3V ADC, so I need to limit max voltage to 3.3V. After testing out some circuits for clamping the voltage(various schottky or zener ...
1
vote
4answers
8k views

What do these dashed/dotted lines mean in this power cord schematic, and how should I ground this device?

--Edited at Sparky256's suggestion for better clarity-- Background Information I'm making a power cable for a piece of obscure, surplus military equipment (an AN/UGC-74B teletype, to be precise). I ...
0
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3answers
308 views

Strange IC input leakage current

I am reading the datasheet of the HEF4894BT. First I saw the input clamping current is rated at 10mA and than I saw the input leakage current would be 10mA, too. I thought the input clamping current ...
0
votes
1answer
2k 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 controller:...
12
votes
4answers
2k 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
333 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 ATmega328P, ...