Questions tagged [driver]

A chip or a circuit that sends a signal with more current or voltage, or over longer distances.

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146
votes
4answers
70k views

How can I efficiently drive an LED?

I understand that I can not connect an LED directly to a battery because it will draw too much current. Thus, there must be something else in the circuit to limit the current. What options are there? ...
56
votes
5answers
19k views

Why would one drive LEDs with a common emitter?

I've seen tutorials aimed at beginners suggest the way to drive an LED from something without enough current drive is this: (option A) but why not this: (option B) Option B seems to have some ...
49
votes
2answers
13k views

Why are USB devices slower than 480 MBit/s

Motivation With a signaling rate of 480 MBit/s USB 2.0 devices should be able to transmit data with up to 60 MB/s. However today's devices seem to be limited to 30-42 MB/s while reading [Wiki:USB]. ...
29
votes
6answers
64k views

How to drive brushless motor with Arduino?

Is it possible to drive a brushless motor directly with Arduino? Or should I revert on controlling a brushless motor ESC with PWM pulses?
26
votes
4answers
43k views

What is the purpose of “MOSFET driver” IC's

There are dedicated "MOSFET driver" IC's available (ICL7667, Max622/626, TD340, IXD*404). Some also control IGBTs. What is the practical purpose of these? Is it all about maximizing the switching ...
26
votes
3answers
3k views

Are there resources for learning to write drivers?

I have a decent amount of experience designing hardware and embedded systems in general, but I have never written a driver for an operating system. I would like to know if there are any good guides, ...
22
votes
4answers
31k views

How diodes protect H-bridge DC motor driver?

I don't really understand how these diodes in this circuit and similar circuits (like driving a relay circuit) protects the controller circuit from the energy stored by the inductance of the coil. I ...
19
votes
3answers
36k views

Is it possible to drive a stepper motor greater than 1000 rpm?

How could I achieve this? What are the stepper motor facts and principless that I have to keep in mind to design a circuit to achive this goal? Are there any readymade/open source alternatives and ...
18
votes
4answers
13k views

Severe ringing when high side MOSFET in half bridge circuit switches on

I have designed a PCB (intended as a prototyping building block) that has a IR2113 high and low side gate driver driving two IRF3205 (55V, 8mΩ, 110A) power MOSFETs in half-bridge configuration: ...
16
votes
2answers
3k views

How to drive 1080p with only 540 pins?

I was trying to hack a 3-D system starting from the monitor: VG248QE. I teared it down to LCD matrix and driver. This is a 1080p(1920 x 1080) monitor so I was expecting that at least 1080(row) + 1920(...
15
votes
4answers
22k views

When to NOT use Totem Pole Drivers?

When is it inappropriate to use a totem pole driver while designing a circuit? Ie. Never use totem pole drivers when... or Totem pole drivers are never used for...
14
votes
2answers
10k views

What is MOSFET gate drive capability and why do I care about it?

Someone told me that this circuit has "poor gate drive capability": simulate this circuit – Schematic created using CircuitLab What exactly does that mean? I tested it with an LED as a load ...
14
votes
5answers
19k views

Driving 50W-250W ultrasonic transducers with sine: Any Class B 135KHz monolithic power amp ICs?

My project needs to drive a medium power ultrasonic piezoelectric transducer from a sine wave (/ sawtooth) sweep generator that sweeps +/- 2% of the transducer resonant frequency. The question: What ...
13
votes
4answers
8k views

Help wanted with Vacuum Fluorescent Display (VFD)

In a box with old components I found a 16 character, 19-segments Futaba VFD: I would like to use it for "something" but I haven't the foggiest how to drive such a display. Even the filament is an ...
13
votes
3answers
10k views

Voltage spikes when driving DC motor with N-channel MOSFET

I'm trying to drive a DC motor (12V, 100W) with MOSFET IRFP054N. PWM frequency is 25 kHz. Here's the schematic: I know DSEI120-12A is not the best diode for this but I don't have any better right now....
11
votes
2answers
1k views

Is it a good idea to connect a line buffer to ground?

Got a quick question. I'm dealing with 74VHC125BQ,115 and I won't be using one of the line drivers; the rest are connected to UART. So, I'm wondering what I should do with the last one. Is it a good ...
11
votes
3answers
6k views

Possible causes for 7-segment LED flicker

I'm working with a vendor overseas to revamp an existing product. We're trying to keep cost down. Currently the product consists of: 4 large buttons 4 double digit 7-segment LEDs. (each button has ...
11
votes
1answer
1k views

SPI transaction timeout linux device driver

I am stuck for last 3 days at a point. I am working on eink device driver with msm8960 qualcomm chipset. Scenario: In file: kernel/arch/arm/mach-msm/devices-8960....
10
votes
5answers
3k views

PWM & output voltage

while 555 contest is long gone, I am still debugging my device, where I already abandoned 555 itself :-) At the moment, I am driving PC fan from an PWM (30kHz) signal from atmel uC. I am powering P-...
9
votes
5answers
14k views

Best way to control 75 LEDs with Arduino

I need to control 25 groups of 3 LEDs or 25 RGB LEDs. Each group will be dismissed from the uC by up to 20 cm (about 8 inches). 20 cm is very safe assumption but I think it will be 10 cm or less. ...
9
votes
3answers
965 views

Can I replace this circuit with an IC?

I moved my Arduino-logic-level-5V-to-12V-LED strip circuit off project board and onto Veroboard and I'm very proud to say everything worked first time: (I'm not at all proud of the soldering job, so ...
8
votes
4answers
9k views

How can I effectively drive multiple LEDs with multiplexing?

I am interfacing my microcontroller (AVRmega32U4) to a 4x4 LED array. There are 2 control lines to operate columns (passed to a 2 to 4 demultiplexer) and 4 control lines to operate rows. I bring a ...
8
votes
2answers
2k views

BLDC and three phase inverter

I want to run/control a BLDC motor from a DVD/CD-rom player and found a schematic how to do this, the so called three phase inverter (see right schematic on this page: http://en.wikipedia.org/wiki/...
8
votes
4answers
11k views

Adjustable linear led driver? Linear, not PWM

I'm working on a product that requires an led to output currents varrying from 0mA to 350mA and as many possible levels in between (~1000 would be sufficient I suppose). I CANT output a PWM signal to ...
8
votes
2answers
4k views

Unipolar and Bipolar Stepper motors

I would like to universal stepper motor driver circuit. Is it possible for one circuit to be able to drive unipolar and bipolar motors with only a firmware change or do they require much different ...
8
votes
1answer
4k views

High Current Pulse on LED

According to Cree Inc Pulsed Over-Current Driving of Cree® XLamp® LEDs app note, driving LEDs with high current pulses can be performed as long as the following guidelines are respected: Based on ...
8
votes
2answers
14k views

Totem Pole Output Driver

I was wondering if someone could explain what a totem-pole output driver is? I have seen the term mentioned in connection to the inner circuitry of an AND gate (consisting of transistors) and in ...
7
votes
7answers
2k views

Mosfet Driver not driving mosfet

I have the following circuit: The MCP1402 MOSFET driver should be driving the BUK7Y13 N-channel MOSFET at 12V, but I'm seeing a much weaker signal which oscillates around 0.7V, preventing the gate ...
7
votes
2answers
22k views

Motor driver using only a 2N2222 transistor?

Is it possible to build a motor driver using only a 2N2222 transistor? If yes, then how?
7
votes
2answers
5k views

Low input voltage noise nV/√Hz

I am using ADA4937 as the driver circuit to my 14 bit high speed ADC. A term in the datasheet is Low Input Voltage Noise is used which is 2.2nV/√Hz. Please explain the importance of this term and unit ...
7
votes
1answer
2k views

Is turning off MOSFET too fast, bad?

As far as i understand turning off a MOSFET too fast, is bad, as high drain-source dv/dt can cause ringing through: a) biasing Parasitic NPN and: b) charging the GS capacitor through DG capacitor, and ...
7
votes
3answers
7k views

Stepper motor troubleshooting with Pololu DRV8825 Driver

I salvaged a bipolar stepper motor (QH4-4242), and a power supply from an old printer that I'd like to tinker with before scaling up to larger motors. With the limited knowledge about the stepper (...
6
votes
5answers
15k views

How does a Line Driver actually works?

So I've searched for days for information about the 74HC244 line driver. As always, the Datasheet provides raw and not very good information about the actual component :) (I mean, it gives us the ...
6
votes
2answers
10k views

Why use stepper/DC motor driver?

Why use or implement a DC/stepper motor controller? Is it not possible to connect the motor directly to an MCU output pin without the driver?
6
votes
2answers
516 views

6V LDO regulator for 6A peak motor

I'm looking for an adjustable or fixed 6V regulator, performing up to 6A peak current. The continuous consumption will be much smaller. It needs to be a LDO regulator, since I will be powering the ...
6
votes
1answer
930 views

Multiplexed Display

Need to develop a user display for a home appliance with: Two digit temperature display (Seven Segment). Four LEDs for 'Power ON' and three 'Modes of Operation' of the appliance. I came across a ...
6
votes
3answers
16k views

How to drive high powered LEDs as efficiently as possible

I have come across some very high powered LEDs. Datasheet for LEDs http://www.cree.com/led-components-and-modules/products/xlamp/arrays-nondirectional/xlamp-cxa2011 My question is: for these high ...
6
votes
3answers
10k views

Best way to control 130 - 140 LEDS with Arduino Uno 32/64 bit led drivers?

I am new to electronic prototyping and had a few questions. I need to control 132 LEDs individually. I want to make 3 rows ( 2 rows of 60 and 1 row of 12) I think i can matrix them but i would still ...
6
votes
2answers
3k views

Laser driver circuit

I like to build a laser pointer driver circuit that I can drive from an 8 bit uC. However, I like to get light output fairly constant. This requires for me to look at the photo detector (these lasers ...
6
votes
4answers
2k views

Multiplexing a Circuit

Frankly, I'm overwhelmed with this circuit that I have to start building in lab tomorrow. Last week we built an octal decoder that takes a 3-bit binary input from 000 to 111 and displays a unique ...
6
votes
1answer
1k views

LED driver circuit interfering with 555 timer?

Below is a circuit I put together that uses a 555 timer and an LED Driver: But the strange thing I see is that the timer does not follow the 1.1*R*C equation. The led remains lit for much longer. I ...
6
votes
2answers
18k views

Stepper motor getting very hot: wrong driver or power supply?

I have built a simple driver circuit for an unipolar stepper motor, based on an ULN2003A. The schematic: The motor is a PM25L. Data sheet is here. It was salvaged from an old electric typewriter, ...
6
votes
1answer
675 views

Higher current LED driver for persistence of vision display

Project needs We need an inexpensive LED driver IC that: Can source or sink at least 15mA/LED Has an SPI-like interface (not I2C) Has a separate latch pin Has at least 256 grayscale intensities ...
6
votes
1answer
3k views

Porting Linux Drivers to RTOS

Everybody is probably going the other direction, moving their systems etc. to linux. I have the following problem. I like to use a WiFi chipset along with its Linux driver on my RTOS (FreeRtos). If I ...
6
votes
1answer
1k views

Controlling DC motors with PWM in MCU

1.Is this the correct way to control a DC motor using the PWM pins in the MCU? 2.How many PWM output pins do you need if you want to use a driver (ex: H-bridge) for each motor and control the duty ...
6
votes
2answers
5k views

MOSFET LED Driver for low power LED's

Now that the music festivals are getting closer this summer, I thought I would build some low-power dancefloor lights for my camp. The circuit I've found is really simple, but unfortunately I am not ...
5
votes
4answers
3k views

How does the Linistepper, open source linear Stepper Motor Drive work?

I have been trying to get the Linistepper to work, however I can't seem the understand the working of the circuit. The circuit is here. The issues that I'm unclear about are: What are the ...
5
votes
2answers
1k views

MOSFET not turning off

EDIT: I just came back from my local Conrad and replaced the MOSFET with a new one - everything works just fine. I really just had the bad luck of having three faulty ones lying around. Good that I ...
5
votes
1answer
820 views

Does a MAX485 need decoupling capacitors?

I am designing a small device with two MAX485 chips. Do they need the decoupling capacitors on the 5V power?
5
votes
1answer
11k views

Why is my constant current source (LED driver) pulsing?

I bought a current source to try to power some high brightness LEDs. The LEDs take 350mA so I found a current source on digikey that matches that and ordered it: http://www.phihong.com/assets/pdf/...

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