An transconductance (using voltage to control current) electronic component used for switching and amplification. Acronym for Metal-Oxide-Semiconductor Field-Effect Transistor. (from http://en.wikipedia.org/wiki/Transistor)

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2answers
49 views

Circuit to Detect State of Output Pin

I am trying to implement a circuit using mosfets that will detect the state of a pin with 2 outputs. The input (I) to output (O) relationship I want is this:
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1answer
54 views

3 Logic Level Transistor or MOSFET

I am looking for a MOSFET or transistor which get fully activated with a pwm signal of 3.3v. I also want to know that can it pass about 1.5 A current. I require it for a nano quadcopter application. ...
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6answers
66 views

How is the current limited in this common drain circuit?

I'm trying to create a dummy load circuit, but it was limiting itself around 1.7A, so I built this circuit. V1 is 0 - 5V via a potentiometer, and V2 is a 5V / 3A power supply. simulate this ...
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2answers
69 views

Pinout of the IRL7833 N-channel MOSFET?

I downloaded the datasheet for this MOSFET, but can't find where it labels the pinout anywhere. Has anyone used these before? I got them for cheap from Amazon, and I'm hoping to control some DC lights ...
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2answers
41 views

share eletromechanical buzzer between 2 mcu's?

I'm trying to 'share' a buzzer between 2 separate mcu's, one is on a multirotor flight controller (STM32 or Atmega328), the other is a module I'm adding that needs to use the same buzzer. diagram: ...
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2answers
55 views

Estimate current through inductor in DC circuit with PWM control

I am designing a circuit to control an electromagnet (coil with iron core) through a N-channel MOSFET driven by a PWM signal. I can't figure out how to derive the relationship between the PWM duty ...
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0answers
34 views

Switch circuit using a dual FET [on hold]

Source: Battery Operated Latching Power Switch. The question of "Battery Operated Latching Power Switch". On-off circuit through a tactile button (power-hold) On: Pressing the moment Off: press ...
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1answer
51 views

Is there a way to use a depletion mode MOSFET “inverse”?

I aquired some surplus led strips and I want to make a certain control circuit for it. I took another goal of using only the components I have laying around. I found a nice reclaimed power MOSFET to ...
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3answers
78 views

Do MOSFETs have voltage drop across source and drain when turned on?

Like diode and BJT having around 0.6V drop, is there any voltage drop across the MOSFET drain and source when the MOSFET is turned on? In the datasheet, they mention diode forward voltage drop, but I ...
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0answers
24 views

finding mosfet driver IC [on hold]

I am repairing a subwoofer amp smps. In the smps the mosfet shorted(no.PFF12N65) and 8pin driver ic blasted. I see a code SK322 on remain part of the smd ic but main code of ic cant see. So I request ...
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1answer
40 views

P-Channel Mosfet + Step-up Converter + MPPT Charger

(because I cannot post > 2 links, I have included digikey part numbers for easy access to the datasheets) I am constructing a circuit consisting of five parts: A 400mAH 3.7V LiPo Supply Battery A ...
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0answers
22 views

Designing a motor driver for my robot

I'm new to electronics and i have a task at hand : to design a motor driver board for my turtlebot(an open source robot) . Having said that , im using a johnson gear side shaft motor that draws at max ...
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1answer
39 views

Reverse bias I-V characteristics of mosfet

What is the equation for a N-channel MOSFET's current value (\$I_{DS}\$) given a negative source-to-drain voltage \$V_{DS}\$? I can find plenty of forward biased I-V curves for the N-MOSFET, but I ...
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2answers
53 views

Can output current be higher than what the input source can provide

One basic question.Am controlling a group of LEDs (connected in series and parallel) through a MOSFET switch.The input voltage is provided by a battery @ 5V,2A rating. The total current consumption of ...
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0answers
26 views

Uneven distribution when using a mosfet for LED PWM drive [duplicate]

I'm using a set of NX3008NBK mosfets to drive a set of mid-range LEDs (~3.3V, ~20mA-60mA) with a microcontroller to apply PWM to control brightness. I am finding however, that the conversion between ...
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2answers
43 views

Replacement for TSM2323 MOSFET

I am working on making a board for the Hummingboard System on Module using the company's board schematic as a guide. They use a TSM2323 mosfet in the "micro SD power on/off" section of their schematic ...
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1answer
35 views

Designing and simulating a common source amplifier circuit

This is the problem: And this is my design for R1 and R2: So, using B2 Spice simulator I made this circuit according to the design: Vin_ and Vout_ are voltmeters. But the problem is that ...
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2answers
48 views

Help driving 9V circuit with a 5V RTC clock interrupt pin (active low)

I am using this RTC clock module (http://datasheets.maximintegrated.com/en/ds/DS3231.pdf). The DS3231 has alarm function that can be programmed twice a day. When the alarm goes off it makes the ...
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1answer
59 views

PWM-stimulated N-channel MOSFET unexpectedly always on

Electronics! I would appreciate help with the following problem: Goal: Get 12V PWM-modulated from a microcontroller-generated 5V PWM. Elements: • IRLML2502, n-channel FET - Datasheet ...
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4answers
355 views

Controlling heater with PWM through MOSFET

I'm trying to control a heater coil (resistance ~0.9 Ohm) with PWM using a MOSFET. PWM modulator is based on LM393, MOSFET is IRFR3704 (20V, 60A). If I place 1k resistor in place of heater ...
5
votes
2answers
79 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 ...
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1answer
58 views

How to connect a four route MOSFET to multiple power sources? [closed]

I have this four channel MOSFET switch: I have connected one RGB LED-strip to this, and controlling it from an Arduino, and this works great. The problem is that I need to control four of these ...
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3answers
440 views

transistor level design of Op-amps

How do we realize the design of a simple Op-amp with Bipolar Junction Transistors or MOS Field Effect Transistors alone? I mean I understand the need for differential amplifiers for providing a ...
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1answer
49 views

Why a MOSFET in accumulation mode is not conducting?

In accumulation mode, the channel is not conducting, whereas in inversion mode it is conduting. But if in both cases I have free charge carriers in the channel, why isn't there conduction in both ...
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1answer
55 views

PSPICE Simulation of Cascode Amplifier Not Working

Can anyone please tell me why I am getting the following "floating node" errors. I have fiddled around with the resistors to see if it affects anything, so these are not the actual values. I have also ...
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0answers
21 views

Signal conversion using MOS

I'm trying to learn the operation of the MOS transistors and I have to convert about 2Mhz (FM) signal to 1V signal at 3.3V without offset. The input signal: What I'm trying to get: If I ...
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0answers
37 views

Charging of battery never ends (using MCP73831-2ACI/OT)

This is follow-up question of this thread. I have three devices MASTER, SLAVE and CHARGER. MASTER has 2 pins, BAT and GND (actually it has 3 pins, third one is for single wire communication, but only ...
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0answers
32 views

Finding an equivalent of BS108 and NDP6020 transistors

I want to implement the below circuit for automatic power off of a microcontroller that will be battery powered: I took this from the following forum: ...
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2answers
80 views

Latching solenoid control

I am working on a personal project that will involve driving a latching 9V/DC solenoid from an arduino. The circuit I've come up with is dependent on two things, that I haven't quite figured out yet: ...
0
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1answer
71 views

Simple ESD protection for MOSFETS

I'm designing a MOSFET (FQP30N06L) circuit to drive a (50V, 3.4ohm) pinball solenoid controlled by a PWM pin on an Arduino DUE: simulate this circuit – Schematic created using CircuitLab ...
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0answers
38 views

Common Drain Design Not Meeting Spec

I am trying to design a Common Drain amplifier with specifications below. I have reworked the problem over 10 times now and have not achieved anywhere near an appropriate solution. I have spelled out ...
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1answer
38 views

High Side PWM motor driving circuit

I have two theoretical question about my circuit (that I have tested with a breadboard and it works, but I want to understand better some design choices): 1) As far the flyback diode is concerned, I ...
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2answers
63 views

JFET hidden wires detector

I want make hidden wires (AC, 220V) detector (circuit is below), based on Soviet p-channel JFET transistor КП103, but JFET's now is very rare. Can i replace this JFET by any low-power MOSFET? My ...
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1answer
30 views

MP3 Player: Disconnect 3-watt speaker from amplifier when headphones are plugged in using MOSFETS and the isolated switch on an SMD 3.5mm stereo jack

Can I use Mosfets to disconnect a 3-Watt speaker from an amplifier circuit without any loss of sound quality? I'm using a microcontroller controlled MP3 player called a Flyron FN-M16P, which features ...
1
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2answers
54 views

Mosfet PWM signal not square

I'm a beginner learning about electronics, currently trying to control a DC motor using a PWM signal. I got it to work, but want to understand what I'm seeing using an oscilloscope and optimize it. ...
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2answers
55 views

Mosfet time and PWM frequency relation

what is the relation that I have to take into account when I select a mosfet(or a transistor in general) for pwm driving about rise/fall/turn off delay/turn on delay and the PWM frequency? How to ...
0
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3answers
33 views

MOSFET chip for discrete CMOS inverter

My plan is to build a discrete CMOS inverter(just out of curiosity) out of two complementary MOSFETS. Hence, I am currently looking for a nice pair of complementary MOSFETS, which is quite hard, ...
0
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3answers
40 views

Switch 15V source with a MOS by digital 0/5V (dc)

I'm trying to switch on and off some 15V devices from Arduino Uno digital ports (0/5V). Each port must control a group of resistive loads (lights) of a train model. There are about 10 groups of loads, ...
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1answer
76 views

PWM with MOSFet- make it linear

there maybe wrong assumption in my question , so forgive me, i am here to learn . So controlling a light(LED) with MCU that outputs PWM, into a MOSFET N-CHANNEL, as described in this little image: ...
2
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1answer
93 views

Controlling direction of current flow through pin depending on the type of device connected

I have a small portable device - lets call it MASTER - which can be inserted into two different accessories - CHARGER and SLAVE. You can check very rough block diagrams in the attached picture. ...
1
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2answers
277 views

Body diodes in MOSFET symbol

As I understand, all MOSFETs have body diode. But I see some symbols have body diode shown while some not. Is there a difference in such MOSFETs?
0
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2answers
57 views

What happpens to the Vgs in the Miller plateau region during MOSFET turn-ON?

During my mosfet switching power dissipation I went through the Vgs curves of the MOSFET during its turn-ON state.Here i found that the Vgs curve remains flat during the miller plateau region. Why is ...
2
votes
2answers
105 views

PWM an AC pump using MOSFET

I'm currently stuck on my project as I'm not sure what to do with PWMing my pump as I want to adjust the pressure. I will be using an Arduino for PWM. The pump is 60W @ 230V 50Hz mains and is a ...
1
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1answer
38 views

Analyzing a small-signal MOSFET circuit

This is the problem: And this my solution: Is it correct ?
0
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0answers
71 views

Analyzing a MOSFET amplifier circuit

This is the problem: And this is my solution: I want to check if it is correct or I've done some mistakes.
3
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1answer
98 views

Analyzing a MOSFET circuit

This is the problem: And this is my attempt to solve it: For (1): I don't know how to get vgs or how to use the hint to get rid of it. For (2): I assume that ...
0
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1answer
20 views

What effect does the drain resistance have on the output voltage of the logic gate?

The logic gate is meant to be a NOR gate, but how does changing the value of \$R_{D}\$ affect the output voltage? Doesn't increasing the value of RD always make Vout lower because of voltage ...
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0answers
36 views

Where are Silicon Carbide (SiC) components useful in lower-power designs (1-10W)?

I am seeing a small but steady stream of aricles on Silicon Carbide (SiC) electronics, particularly MOSFETS and diodes. Most of the articles are aimed at high power electronics, mostly due to the ...
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2answers
375 views

What's the middle terminal in the VN2222 MOSFET?

In the VN2222 MOSFET below (diagram is from PSPICE), what is the terminal with the arrow pointing in? The one to the left is the gate, above and to the right is the drain and at the bottom is the ...
0
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0answers
36 views

Arduino Uno switching between usb and external power [duplicate]

I have some confusion on the Arduino Uno circuit for switching between the USB power and an external 7-12V power supply. In the schematic ( http://arduino.cc/en/uploads/Main/arduino-uno-schematic.pdf ...