Questions tagged [transistor]
A semiconductor component used for amplifying or switching electrical signals. Use this tag for discussing transistor circuits.
106
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Arduino resets when 10k pot is set to max value [closed]
I have a simple circuit, where a use tone in order to send a melody to a speaker.
Then I added a 10k potentiometer, along with a BJT, in order to control the volume.
This is the schematic:
A weird ...
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1
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2
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138
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PWM with a TRANSISTOR on flexible LED filament
I would like to create a custom lighting, with PWM capability, powered from battery. I would like to use flexible led filaments, and since those consumes more than 40mA, I can't use them directly on a ...
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-1
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1
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167
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Problems in running two solenoid together at the same time
I am trying to activate two solenoids (12V/350mA, connected to a 12V/1A adaptor) at the same time using the TIP120 NPN-transistor and 1kohm resistor using the UNO board. Using a simple program,
void ...
4
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2
answers
739
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Controlling a 5V fan and ultrasonic fogger with an arduino - do I need an external power supply?
I know the whole controlling a fan with an arduino thing is getting old, but somehow I still don't get it to work. Tried to answer it based on other questions but I am too much of a newbie to ...
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0
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1
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611
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arduino 28BYJ-48 stepper only whining, not rotating
Edit, this question has been answered in the comments by chrisl, and also after retesting the code with delay() which showed I forgot to update my lastupdate variable(eerst), I have answered it in the ...
- 154
0
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2
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290
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Switching fan on with transistor, fan running very slowly
I want to control a fan with an arduino from 0 rpm to full rpm. Using a (modified) pwm signal from the arduino I can control the speed w/ the pwm signal, but it cannot go all the way to 0 rpm.
So I ...
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0
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160
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PID cooler temperature control
Hello Hello I am making a controller of a small cooler (dry ice) PID but Im not sure if I am using the indicated mosfet
Im trying with a NPN 222a
and my second option is IRFZ44
Which would be the best ...
2
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3
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280
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Why are transistors necessary before LEDs?
Below is the small RGB LED circuit I'm trying to build. My question is why are the 3 transistors necessary, and can I not link the LEDs directly?
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3
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2
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103
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connecting a small motor to arduino using a transistor
I want to connect a small motor (water pump) to an arduino, and I am not sure about the circuit.
The pump is small, works with 3.3V, but consumes 0.1A so I decided to use a transistor. The one I have ...
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0
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1
answer
303
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Motor not switching with 2N3904
I have a small motor, it powers fine from the 3V3 and GND output of the arduino nano ble 33. However I need to be able to switch it on and off. My first attempt was to use an output pin, but that ...
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0
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1
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113
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Switching 4.2V circuit with 3.3V Arduino GPIO
I am trying to learn about MOSFETs and see this p channel MOSFET and this tutorial. I am trying to use a 3.3V arduino GPIO pin to control a load that is powered from a 4.2V battery in much the same ...
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1
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46
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Is it possible to use the same power source for the arduino and a high current
I've need to control some leds which draw 300mA with an arduino (actually an atmega) and after some searching I think the following is the circuit I need, but I'm not really sure if the power source ...
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1
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1
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222
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Arduino H-bridge for rc car
I've got an old rc car laying around, of which i would like to swap the insides, but re-use some of the parts that are already in there. The car runs 2 dc motors: one for steering, one for throttle. ...
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137
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Motor not working when using Nano 33 BLE and transistor because of low voltage
I'm a beginner using a new Arduino Nano 33 BLE to power a low voltage motor. I've tested that the motor can run using a standard 1.5V AA battery when connected directly, but I cannot get it to work ...
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1
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116
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How can a DC motor (toy) be run with only an Arduino and transistor without an external power source?
I'm trying to understand this circuit found here.
I understand that the Arduino cannot directly run a DC motor because it can only supply 40mA of current and also due to the back EMF which can damage ...
0
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2
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204
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How to use a push button & transistor as a kickstarter for power supply?
My goal is to save energy, and I intend to do so by powering a chip with itself, and cut power whenever unnecessary. The best image I can have is of a startled monkey who jumps on the branch, screams ...
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1
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92
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Variable Fan Controller - Properly Sized Transistor
I would like to a build a temperature sensing variable speed fan controller for my truck. Currently using a purchased 2 speed on/off relay based controller, but my fans are overloading the whole ...
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1
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Why is it I need transistors and resistors to turn a DC motor with an Arduino but I can connect it directly to a battery?
As the question says: I'm building a circuit to run a DC motor whenever motion is detected by a motion sensor. Now as this image suggests:
I need a diode + resistor + transistor to get this thing to ...
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0
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2
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1k
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DC motor fan speed control with Temperature Sensor [duplicate]
I used this circuit schematic for the project however, when DC Motor starts to work, temperature value is increasing abnormally high. How can I solve this problem? It shows abnormal high values like ...
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2
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1
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45
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Why won't my motor run?
I am trying to run a small 3v motor with a Keyestudio MEGA 2560(which is the same as the Arduino MEGA 2560). I am getting a consistent 5 volts everywhere I check with a multimeter. The voltage drops ...
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1
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111
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Unreliable function of transistor, pump and ESP32
I have a 12 VDC pump, 8.5A, connected to a MOSFET transistor PSMN5R6-100PS,127.
The connection from the transistor to transformer, pump and a ESP32:
1 Gate --> port to ESP32
2 Drain --> ...
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1
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0
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33
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How can I power off a servo the best way? Problems with MG90S servo [duplicate]
I have a NodeMCU and im trying to control a servo to move from angle A to B and viceversa. The thing is I want to be able to power off the servo after moving so it could stop getting voltage and ...
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2
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Read encoder output by using an optocoupler
I have a 512 pulses encoder with four wires: +5V, ChannelA, ChannelB, GND and I'm using it as feedback for my motor position (max 80 RPM) on Arduino UNO. Everything works fine, but I need also to ...
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2
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2
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234
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Why does controlling power with a transistor interfere with MHZ19B's serial communication?
I've been trying to turn off an MHZ19B (datasheet and teardown photos: revspace.nl/MH-Z19B). I've used an Arduino, NPN, PNP transistors and mosfets as well as the diagram below for connecting the ...
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1
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575
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BJT - BC547 not working with LED strip
I'm connecting an LED strip that takes 12V input to an Arduino Uno R3's 5V VCC using a B547 transistor.
Here's my circuit:
Base -> 1K ohm resistor -> DO13
Collector -> -ve of LED strip
...
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5
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1
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964
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Switching a Solenoid Using Arduino's 5V Output?
I'm a bit stumped on how to switch on a solenoid using a transistor using my Arduino Nano's 5v Output. The solenoid runs on 12V, so I used an NPN transistor to connect the 12V source to the solenoid ...
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1
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122
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Relay + Arduino uses too much power for battery to handle. Which solution is best?
You can see in my crumby schematic that I am using a Non-latching relay to turn on a 3A circuit (one of them arc lighters), which is powered by a 25C (supposedly) lipo battery. That same battery also ...
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2
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334
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Arduino 5V pump digital pin
I am trying to control a 5V pump with arduino and ultrasonic sensor however i can't make it work with the pump connected to a pin.
I saw on the forum that you need transistor or relay but i don't ...
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2
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699
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Arduino MKR 10100 control DC Motor
Thank you for reading my post. I have been stuck on this for several weeks now! I am trying to turn ON/OFF a DC motor from Arduino IOT Cloud. I have set up the cloud and added the switch. Everything ...
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0
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1
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452
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24v LED strip with common anode?
I have a 5m strip of 24v tunable white LEDs and I'm trying to figure out what I need set it up. There's a pad for V+ and then one for brightness and one for warmth. If I plug the V+ in V+ on a 24v ...
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57
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Control 12V power with 3 transitors to 3 seperate consumers
I have this shematic. With one electrical Pump and two solenoid valves I want to control via the arduino.
Here are the specs for the parts:
Pump: 12V max. 250mA
Valve 1: 12V max. 160mA
Valve 2: ...
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5
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Why does the transistor burn out
I have an arduino uno which turns on a water pump (12V, 3.6W) once every 10 hours for a few minutes (I've followed this tutorial on how to connect the water pump). To turn on the water pump I used a ...
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1
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3k
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Using an NPN transistor as a switch to turn on/off a DC Motor
I am trying to control a 3V DC motor (FA-130) with my Arduino Uno, and am trying to do that using an NPN transistor (2N3904) as a switch, as shown in this diagram.
I used the Blink example and ...
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2
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How can I use a transistor to "press" a button?
I have a heater remote that I want to press the buttons of with my Arduino. I am powering both the remote and Arduino from an external 5V source so both grounds are connected.
Currently I have tried ...
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1
answer
2k
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LED not blinking when using a transistor
I want to control an led using a transistor. The led gets it‘s power from an external 5v dc power supply.
For the transistor I use an 1kΩ base resistor. The transistor is a BC547C (npn). The ...
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1
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593
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Can you drive a stepper motor without the L293D
Can you drive a stepper motor without L293D.
Don't awnser without giving explanations or saying it will be cheaper to buy the L293D.
Thanks
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1
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307
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Controlling a 5m LED strip with a Nano or Uno
I'm wanting to control a 12V LED strip (5m, 60 LEDs per meter) with a Nano or Uno. I know from Adafruit that I'll need some power transistors but I'm not sure that I have the right type. I have 6 ...
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1
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1
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246
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Water tank false trigger
I am trying to make a simple water overflow protection system for my home. I have created it using BC547 and NodeMCU (ESP8266). I have a simple circuit like this:
The problem here is I have 2 wires ...
- 215
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3
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298
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Arduino Uno with 6x 5V solenoids + 9V battery - Not enough power?
I have 6 5V solenoids connected to an Arduino Uno, each of them with a TIP120 transistor, diode and resistor. Exactly like https://core-electronics.com.au/tutorials/solenoid-control-with-arduino.html ...
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Arduino LED PWM dimmer starts blinking on low PWM values
I'm trying to build a PWM led dimmer with Arduino using this circuit:
simulate this circuit – Schematic created using CircuitLab
Everything works fine until the pin PWM 3 drops below the ...
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1
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652
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12 V relay using Arduino [closed]
I want to control a 12 V relay using an Arduino 5 V signal, but due to some unknown reason the relay does not work. I am using a BC548 transistor as a switch for relay.
Please suggest where I go wrong....
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2
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How is this simple transistor circuit suppose to work? [closed]
I've tried to replicate this circuit today.
My motor is a computerfan, they apperntly don't need a flyback diode since there are no brushes.
I used a 12V power source for my arduino and hooked it up ...
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1
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249
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Sanity check for dual IR LED circuit [closed]
If the intent is to drive the two LED's with 200-400mA (using PWM @ 38Hz), is there anything wrong with this solution?
Perhaps this is a better solution, as it ensures the current is exactly the same ...
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2
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358
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Vary voltage using relay. Is this possible?
I am planning to control a RGB lamp using Arduino. The lamp is 24V and I want to be able to control the brightness of the lamp. I found a relay that will let me control the 3 channels (red green and ...
3
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1
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770
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What's the function of this transistor on Arduino Mega?
I am trying to get information about the transistor on the Arduino Mega board below:
It says "340P" on the transistor. I want be able to know which model transition is this so that I can check its ...
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1
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Solenoid "vibrates" instead of pushing
I'm using my Arduino Uno to control a 5V 1A solenoid.
I'm using an N-Channel MOSFET linked to the Uno's 0 pin to switch the solenoid on and off. It is protected by a Schottky diode. Initially, I ...
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1
answer
608
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Making an H-bridge with transistors [closed]
I am trying to make an H-bridge with two NPN and two PNP transistors to drive a motor which works fine on the 5 V Arduino. I have a schematic in the picture. When I use a simple code to have pin 9 ...
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2
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0
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88
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Do I need one N3904 for each LED?
I want to control 4 (or more) LEDs using the PWM output pins of my Arduino.
Here is how I have it on a breadboard, and it's working for me.
Question:
Is this schematic inefficient? Are there any ...
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1
answer
719
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Transistor as switch for signal and high current buzzer [closed]
I'm a newbie in transistor switching.
I have PIR sensors with C and NC onboard. NC is 12 V signal that I need to switch transistor (bipolar?) to emit 3.3 V (collector connected to 3.3 ...
- 101
0
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2
answers
5k
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Dim a led using a NPN transistor
I know there are a lot of questions about this topic, but I've tried everything and any possible guide online without success.
I want dim (increase and decrease the brightness) some leds (3.5 Watt ...
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