Questions tagged [input]

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

-1
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1answer
99 views

What does “LB” out mean in a DC-DC buck converter?

Teacher gave me a schematic,and it includes a DC/DC buck converter with "LB" input and output,but i have no idea what the "LB" is,so i want to ask that does someone know what may the "LB" be?
0
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3answers
70 views

Wide Voltage Automotive Status To Microcontroller Input

I need to monitor the status of a wire in an automotive application that can have 10-40VDC on it at any time. What is a good approach to limit the voltage to a microcontroller input across such a wide ...
0
votes
1answer
82 views

Input of boost converter or charge pump in the energy harvest [closed]

I read some paper about the energy harvest, and lots of paper said the induced voltage from, for example, the thermo-electric harvesting could be as low as tens of millivolts in a realistic case, so ...
0
votes
1answer
70 views

ST10F269Z2T3 abnormal Input Logic Levels

We are using a ST10F269Z2T3 Microcontroller (Datasheet) in one of our old Designs. Among other things, the ST10 monitors the functionality of external devices using Standard logic Inputs. Eg.: Input ...
0
votes
1answer
122 views

Tristate driver I/O for analog signals

In FPGAs a tristate drive is used to convert a pin from an input to an output or vice versa. Now this works only in digital circuits. Is there a way how you could obtain the same functionality of ...
0
votes
1answer
363 views

Wide voltage range input regulation (24V - 3.3V)

TL; DR: I need a circuit capable of handling input voltages from 24V to 3.3V (with a 10mA/5mA maximum current) and delivering 3.3V to the microcontroller (ESP32) input. Recently, I've been working ...
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votes
1answer
115 views

How I can get a high level with this circuit? [closed]

simulate this circuit – Schematic created using CircuitLab I have this circuit. The MCU on the right select speaker output if I have a low level and if i want audio jack output, i need a high ...
0
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1answer
33 views

Maximum input capacitance of IO-Link-Device on C/Q

I have a bit of trouble understanding the IO-Link-specification concerning the input capacitance of the C/Q-pin. The specification says in table 7 (line 754): CQD Input capacitance min: 0 max: 1,...
0
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1answer
86 views

How would you calculate the input and output impedance of this amplifier?

How would you calculate the input and output impedance of this amplifier? I have done a lot of research and found so many conflicting pieces of information. Not sure what is right. C1 = 10Uf, C2 = ...
0
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1answer
137 views

Input circuit for ESP8266

I built the following simple circuit as an input to an ESP8266 microcontroller: When I hold the switch closed, the input goes low. How do I modify this circuit to do the opposite? I want to press a ...
4
votes
1answer
379 views

Associate std_logic_vector constant with input port VHDL-200X

I am trying to configure a chip over SPI interface using FPGA Spartan 6 Eval board. I just need to configure, I do not need to read the data from the chip, it will be done by another interface. ...
0
votes
2answers
98 views

Powering 5V IC with 3.8V

I'm trying to power a ESP8266 and ATMega128 from a LiPo battery via the TP4056 charging module. I get 3.8V out of the charging module. According to the ATMega128 Datasheet it is possible to power the ...
1
vote
1answer
1k views

in SPI, can MOSI and MISO be connected together?

I'm using an 8051 series microcontroller, and documentation states that if I use serial mode 0, then its RXD pin can function as a bi-directional pin (both input and output) while TXD is strictly a ...
1
vote
1answer
92 views

Input voltage limits of AD8495 (thermocouple amplifier) vs supply voltage

I'm working on an android multigauge for cars based of a pic microcontroller. Some inputs from sensors are not fed by my circuit so after stumbling upon this thread: http://www.microchip.com/forums/...
1
vote
2answers
90 views

What is a “current load” on a 24 V input used for?

The MAX14821 (datasheet) is a 24 V IO device that features selectable current loads for use in actuators on the inputs. What would this be used for? It's not just ...
0
votes
2answers
144 views

Audio ADC voltage level SNR question

I keep looking for Audio specific ADCs and the majority of these devices work at low voltages on the analog circuitry (5V for example). Lets say we want to process an higher voltage audio input ...
0
votes
1answer
203 views

Connecting a coin receptor to a key press

I want to connect a coin receptor to a keyboard press. I want to have an arcade cabinet with my computer game running. It should only add credits when a specific key is pressed, which can be ...
12
votes
3answers
2k views

12 V input on 3.3 V GPIO, TVS pulled down or Schottky pull up?

I am building my own PLC that has to accept permanent inputs of up to 30 V DC into a STM32F with 3.3 V inputs. The switched input will have to work with 8-30 V, but 90% of the time the ...
0
votes
1answer
421 views

designing a universal 0-10v and 0-300k resistance input circuit

I'm trying to design a universal input circuit which can accept 0-10v as well as variable 0-300k resistance. I'm using this ADC (mcp3008) which has a maximum input of 5 volts , couldn't find an ...
1
vote
1answer
74 views

Can I use a similar AC adapter with different input but the same output?

I have a landline telephone from Japan. The owners manual says only use OUR AC adapter, {Input 100v 50/60Hz 8VA - Output DC 11V 430mA} I want to use this in North America - can I use a AC adapter ...
2
votes
1answer
835 views

Vbe vs Ic characteristics of NPN transistor at different Vce in active region

Below is an NPN transistor characteristics for Vbe versus Ic at different Vcb or Vce: It seems like in the active region, Vbe vs Ic curves gets steeper with an increasing Vce. The following ...
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3answers
2k views

stm32f4 vdd and interfacing input pins

The stm32f4 discovery datasheet DS8626 specifies vil and vih as below So I have some questions based on the documentation How do I know that what value VDD is operating at if I use the usb to power ...
2
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2answers
267 views

AT32UC3C Negative ADC Input Voltage

The AT32UC3C ADC can be set up using either internal or external references as seen in Table 36-8. For any type of voltage reference used, the datasheet suggests that the ADC is capable of converting ...
1
vote
2answers
110 views

Signals shorted when connected to the input of an unpowered IC

I use one SPI bus from CPU to two FPGAs with different (i.e. individual) CS signals. The CPU and first FPGA are powered up, and the second FPGA is unpowered. When I send SPI signals to both FPGAs, ...
0
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3answers
309 views

PIC16F15345 Microcontroller, RA5 Digital Input Pin Issues

I've been having a very strange problem with my PIC16F15345 microcontrollers. I'm trying to read a digital input state from a specific pin on the microcontroller (Pin2, or RA5). My setup code is below:...
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0answers
125 views

Diode populated keyboard matrix: Wire two separate buttons to the same output?

I have an encoder board for a 16x8 row/column switch matrix. An absolute beginner to electronics but using all of the great online resources for research the best I can. However, occasionally it turns ...
0
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0answers
43 views

How to decide maximum input current required in linear charging method?

I am using MCP73213 IC for my charging application. I would like to use the maximum capacity of the IC for charging. i.e., 1 ampere charge current during constant current charge cycle.And input ...
0
votes
3answers
263 views

Analog Input Voltage for Agilent DSO-X 2002A Oscilloscope

How can I find the minimum analog input voltage for an oscilloscope? I've checked the datasheet for the particular one I am using(Agilent DSO-X 2002A) and only the maximum input voltage is listed.
1
vote
1answer
515 views

Sallen Key topology input and output impedance

Ideal Operational amplifier Zi=(R1+R2)||Zc2 Zo=0 741 Operational amplifier Zi=(R1+R2)||Zc2 Zo=0 (at DC) For the input impedance when using a 741 I am not sure if I should consider the Fairchild ...
1
vote
1answer
129 views

harvested a joystick from a fight con, want to use it to take input into an arduino. how do I wire up the switches?

the joystick is just 4 switches around a shaft (up, down, left, right)- 0, 1, or 2 of them are engaged depending on direction the joystick is being pulled. here are some images showing what I'm ...
2
votes
1answer
325 views

Can you use a stepper motor as input?

I'm not too versed in EE so I apologize for my duncitude - My thought is that you can precisely control a stepper motor, but can you inversely get precise readings out of a stepper motor? For ...
1
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0answers
487 views

Audio input: stereo to mono and filtering DC

I have to get an audio input from a PCB 3.5mm jack and summing right and left channel into one (mono). Then, I have to filter any DC noise from the input. Resistors are 1kOhm each. This, for now, ...
8
votes
10answers
4k views

12V input on microcontroller pin

I'm trying to count pulses/sec. on a microcontroller pin in the ~5 to 100Hz range. The µC can operate at 5V input, so I have to get the voltage level down safely. A simple resistor comes to mind, yet ...
1
vote
2answers
2k views

Matching sensor output with PLC input

I am trying to add a height captor for a line of my production where I work. I found this Banner captor (QS30LLPQ) and it has 2 bipolar discrete outputs (PNP and NPN). Now, I am trying to decide which ...
2
votes
1answer
90 views

Where does my negative input voltage come from? [closed]

I'm a bit confused about the concept of an input ground for an op Amp. Let's say I'm amplifying the output from a 555 timer ic. I assume the output pin from the 555 is my positive input but what is a ...
0
votes
1answer
56 views

How to determine a system is stable without knowing the input?

I was doing some exercises for an upcoming exam and ran into this. I am not sure how to find if the system is stable without knowing the actual input (since Routh array is the only method I'm familiar ...
0
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1answer
42 views

How to find out a register contains inputs or outputs or both?

I don't have much experience with embedded systems and I am trying to check if is possible to determine if a register is made of inputs or outputs or a mix of inputs and outputs. Let's say I have a ...
0
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2answers
92 views

Can I make or find a device that will switch between DC inputs on a priority basis

So my problem is i have 3 Hot DC lines that normally will only have one powered at a time, but if more then one powers on at once i want only one of them to pass through since they are used as ...
0
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2answers
506 views

Gain due to Input Voltage Offset in op amp

For a lab, I need to calculate the gain due to the input voltage offset of an op amp. This is the circuit below: This looks like an inverting op amp to me; so I was thinking the gain would be -1M/...
1
vote
1answer
102 views

Read 60 potentiometers and 30 switches

I'm pretty new to hardware stuff. I have a basic idea to build a hardware controller for some proprietary software. I would need to read about 60 analog faders/potentiometers and 30 buttons. Also I ...
1
vote
2answers
255 views

Protecting Electronics From Sustained Overvoltage (36-60V)

I have a problem I need to solve. I have a power filter circuit that looks like this: The input voltage is 18V to 32V and I need my circuit to be protected during overvoltage situations. I have ...
1
vote
1answer
1k views

Spartan 6 bidirectional pins how to use

Is it possible to use pins of Spartan-6 bidirectional. (switch between input/output) The following is the situation: I have a high speed ADC and DAC, but this do not have to opperate at the same time....
1
vote
2answers
145 views

A huge number of buttons on a Raspberry Pi

I am working with a friend (he's got the vision, building the structure, I'm working on the electronics) on a large scale project that involves a grid of pictures illuminated by an LED at the push of ...
0
votes
1answer
364 views

Help! Arduino `INPUT_PULLUP` not inverting

I have a situation where I tried setting pins on my Atmel Mega328P to INPUT_PULLUP. I was told to expect an inverted input: a +5V would result in ...
1
vote
3answers
1k views

BJT Input AC Signal Amplitude

This question is referring to npn BJT CE: If we look at base voltage vs. collector current plot we can see that at approximately 0.7V on base to emitter junction, the BJT starts rapidly conducting. ...
0
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2answers
570 views

Input selection for dry contact vs pnp

On my board I have to acquire dozens of input digital signals. Each one might be a dry contact or pnp (12V). I have to isolate them from the MCU side. The basic circuits could be: dry contact: pull-...
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2answers
288 views

Using HDD as an input device for Arduino

I'm wondering if is it possible to use an old HDD as an input device that would feed some kind of data to Arduino. If you manually positioned the head and platter (the disk is not spinning, so it ...
2
votes
2answers
765 views

Finding the input resistance of an oscilloscope

I'm having a little trouble understanding how to do this problem. So an oscilloscope measures a battery voltage of 1.5V, and when a 1M(ohm) resistor is put in series, the oscilloscope only measures 0....
0
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0answers
63 views

Too low voltage on digital input on attiny45

I'm using one of my attiny's pins as digital input. I am using a 2k2 pulldown resistor on the input. I am applying a simple square wave generated by a separate waveform generator. The high state for ...
0
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1answer
335 views

Can I use MOSI, MISO, SCK pings for reading input in AT89S52?

I am doing a custom keyboard for my project. It has totally 22 keys. I am using AT89S52 microcontroller. I have allocated P0.0 TO P0.7 AND P2.0 TO P2.7 AND P1.2, P1.3, P1.4 (totally 19 pins) which ...