Tagged Questions

0
votes
0answers
37 views

PWM Control with MOSFET switch

I plan on using a 555 timer for a PWM signal (variable with a potentiometer) and a gate driver to use a MOSFET as a switch. Essentially, I am trying to take a +300V rail and "step" it down using the ...
3
votes
1answer
130 views

Criteria behind selecting pwm frequency for speed control of a dc motor?

I'm working on a speed control circuit for a brushed dc motor (24v, 500rpm, 2A, 4kgcm). The main components that I plan to use are PIC16f873, 4n25 optocoupler, IRFZ44N MOSFET, BY 500 - 800 diode(for ...
2
votes
1answer
92 views

Simplest design approach for PWM control with power MOSFET

I'm designing an application in which the current running into a load is controlled by PWM. A microcontroller generates a PWM cycle at 20kHz and this signal is used to control a MOSFET which is ...
0
votes
2answers
75 views

PWM controller to meet EMI/EMC regulations

I'm designing an application in which the current running into a load is controlled by PWM. A microcontroller generates a PWM cycle at 20kHz and this signal is used to control a MOSFET which is ...
1
vote
2answers
262 views

PWM Motor speed control using PIC; What mosfet to use

I have a 5V PIC16f877a controlling the speed of the motor 12V which has a power rating of 8W; the current will be around(600mA) am I correct? The motor is basically a small water pump commonly used ...
2
votes
1answer
113 views

PWM & NUD4001 LED driver

Today I tried to build a small circuit which basically consists of three NUD4001 LED driver, three n-Channel FETs and a RGB Power LED from SEOUL. I don't have the exact specs ready but the main specs ...
2
votes
4answers
323 views

Picking out correct MOSFET for solenoid PWM control?

I'm attempting to control an automotive solenoid with PWM at 1250hz. At peak, the solenoid draws 3.75 Amps at 14.4 Volts. The specific problem is that any MOSFET that I've tried gets too hot and ...
1
vote
3answers
286 views

Scaling PWM amplitude by switching an analog DC voltage?

I'm trying to make a quick-and-dirty voltage-controlled volume control circuit, using a minimal number of components. A microcontroller is outputting two 5V p-p, 625 kHz PWM signals: an audio ...
2
votes
4answers
647 views

Why is the MOSFET driver in this circuit dying?

This circuit kills the driver (an IR2104s) when under normal conditions. Bat+ goes to a 12V lead acid battery. In+ goes to a 20V laptop power supply, though it is intended to be a solar panel ...
1
vote
2answers
648 views

Transistor / mosfet for PWM dimming of 30W RGB LED

I am building a led mood light with a high power RGB LED (30W) using 3 constant power supplies for each color. These are the items I had in mind (but open to suggestions): 30W Integrated RGB LED ...
10
votes
3answers
719 views

What is a popular cheap and robust substitute for 2n7000 MOSFET for use with 3.3 Volt designs?

First off, this is not a shopping question, it is an attempt to harvest the knowledge of all the EEs who may have crossed the same bridge the question describes. Question: What are the popular ...
1
vote
1answer
634 views

How to drive a high-side N-channel MOSFET with low VGS?

Question first: Is there a bootstrap driver that is available in DIP, works similar to the IRS2001, but is OK with a VCC of 4-5V? I'm also a bit limited in the amount of space I have -- is there a ...
6
votes
4answers
1k views

Is this a good design for MOSFET H-Bridge?

I have been looking around trying to design a simple but working H-Bridge for an RC car motor (12V and 2~3A). This bridge will be driven from a microcontroller and need to be fast to support PWM. So ...
2
votes
1answer
254 views

24 channel PWM IC

I wan't to drive 8 RGB LED stripes (8 stripes * 3 colors per stripe = 24 channels) with PWM. Each output is driven with a logical level MOSFET. The stripes already have a resistor. I have looked at ...
2
votes
1answer
171 views

Help Choosing a mosfet

I would like a little insight on choosing a Mosfet for a hotwire cutter. The wire runs 12v @ 2A I am planning on using a 555 PWM circuit to control the temp on the wire. I plan to use the PWM signal ...
1
vote
2answers
831 views

ATtiny25 PWM LED driver with brightness control

I'll be building a piece of RGB LED jewelry for my beloved one for the holidays. It's basically a pair of earphones with one or two RGB LEDs on each, with a small ATtiny25-based PWM driver in a small ...
1
vote
1answer
547 views

Safe to use PWM source to control lights via MOSFET?

I'm a bit of a noob when it comes to electronics so looking for some advice on this project I have in mind. Introduction The goal is to have my garage door opener (GDO) switch a secondary set of 12v ...
4
votes
1answer
184 views

Maximum switching speed of a motor

If I have a MOSFET (or a number of paralleled MOSFETs) driving a motor, what determines the maximum bandwidth (PWM frequency) at which I can excite a motor phase? Is this only a function of the total ...
8
votes
5answers
670 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 ...