Linked Questions

2
votes
3answers
6k views

Pull up on NPN transistor (during microcontroller power up)

I am using an ESP8266-01 to control a 3.3v relay via a 2N2222A NPN transistor. The ESP8266 GPIOs use a 3.3v logic level. The idea is that by setting GPIO2 to hi/lo I can saturate/cut off the ...
2
votes
1answer
6k views

How do I do a basic MOSFET wiring? [closed]

I have searched "how to wire a MOSFET" in a few different wordings and looked at a bunch of MOSFET wiring diagrams, but I can only seem to find the more complex examples of a MOSFET wiring. Currently ...
2
votes
2answers
4k views

MOSFET for 5V high-side switch

I have a 5V logic signal coming from a pin on my microcontroller. I would like to use this to turn on and off another circuit which also runs at 5V. i. e. the logic level is the same, but I need to ...
2
votes
1answer
3k views

DC fan control using an arduino UNO and a N channel MOSFET

I am trying to produce a variable speed fan control using an arduino UNO. I tried something using a BJT which didn't work and so it was suggested that I use a MOSFET instead. I am just looking for ...
0
votes
4answers
731 views

Logic-level switching 12v

I implemented the following schematic trying to follow Jon Watte's reply to this question. There are two things I don't understand: Why is the probe Q14 showing 4.34 volts? Why is it not closer to ...
1
vote
2answers
757 views

P-channel MOSFET with variable resistance on the drain

I would like to switch a variable resistance using a P-channel MOSFET as a high-side switch. I asked a similar question here using PNP BJT; however, it appears as though a BJT would be inappropriate ...
0
votes
1answer
870 views

Drive 12V load with 5V PWM

I want to control a 12V heater coil with 5KHz 5V PWM using the below circuit, but the load voltage does not goes higher than 5V. I made a similar circuit with a MOSFET and the result does not changed. ...
0
votes
1answer
467 views

How to control brightness of high power LED with PWM microcontroller (ATMEGA16)

Hi I am entirely new to the PWM concept. I have an AVR based ATMEGA16 microcontroller (https://robokits.co.in/control-boards/rhino-robot-control-board/rhino-robot-control-board-avr-based-with-quick-c-...
0
votes
1answer
440 views

Using Arduino + MOSFET to automate the pressing of button

I am working on using Arduino Uno to automate the pressing of buttons. The configuration to the left is the current configuration and it works fine. However, the configuration to the right doesn't. ...
0
votes
3answers
178 views

Help in choosing correct power supply for LED matrix

I'm quite new to electricity and electric components. I'm building an LED matrix from scratch on a small PCB. I will be using an IC for multiplexing, Transistor for controlling external power supply ...