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MOSFET
Sci.Electronics.Basics is a worldwide Usenet news group that is used to discuss basic electronics questions.
We found 274 threads matching "mosfet"
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The most relevant threads are listed first
mosfet gate drive impedance
gearhead - 2008-01-14 15:15:00
I have a situation where I need to use a pretty stiff pull-up resistor
on a mosfet gate because I'm going to use a comparator
to turn it off, and I plan to limit the current the comparator sinks
to about 5 mA.
The N-mosfet source will be sitting at 15 volts and the gate drive
comes from a volta...
mosfet driver question
2007-01-12 14:35:00
I'm thinking of getting a TC1427 mosfet driver to power a motor by
parallel port. I'm about to place the order, then I thought of a few
questions:
Can I drive a 1A load directly from Pin 7 of the TC1427? Or is this a
bad idea?
For greater loads, the gate of a mosfet (say, IRF530) gets con...markvelectronics.com out of business??? (I bought a Mosfet from them)
2007-07-24 01:20:00
AF-2 120W-250W MOSFET Power Mono Amplifier ( 6 lbs.) 89.80 114.80
I bought a MOSFET at markvelectronics.com, but the advertised part is
still posted for $89.80. Are they out of business??? (
http://www.markvelectronics.com/store/ )
Its still under warranty (5 years)!
Anyone help?
Thank...Driving Dual MOSFETs From A NPN Transistor
Michael - 2006-12-12 18:49:00
Hi,
I'm working on a circuit that uses a NPN transistor to drive (i think that's
the right word) two MOSFETs. Could someone please explain how to work out
the theory behind it? For example what value resistors I need between the
gates and emitter, etc. (i presume I need some). I'd like to ...TRYING to compare bipolar, Fet and Mosfet transistors
chriswilliams - 2006-10-04 19:21:00
Hi all:
I am trying to compare bipolar, FET and Mosfet transistors
Could be said that the FET and MOSFET are transistors of a greater
amplification capacity than the bipolar but they carry out the same one
function that is to amplify?
In various circuits they seem to be used for the same f...hw was mosfet @Bodyeffect
2007-02-01 17:25:00
HAi,i want full graphs,formulus,and explination of bodyeffect on mosfet
...emitter followers / Darlington - need help
2006-12-14 11:39:00
Hello,
I'm trying to use a low-voltage signal from my PC's parallel port ( <
5V) to activate the gate of a mosfet, which will switch a 9-12V supply
and lamp.
Something similar to this, under "NPN Darlington Configuration":
http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/emitfol.html
...MOSFET gate circuit for PWM drive
pimpom - 2008-10-05 15:37:00
Can anyone please explain (or suggest online reading that
explain) what factors have to be taken into consideration when
driving a power MOSFET with a PWM signal for power control such
as motor speed or power supplies, especially at the gate?
I understand that a MOSFET gate is essentially a...Mosfet
Roger Dewhurst - 2007-10-15 17:44:00
How are the pins of a mosfet identified please.
The project requires a 45V/16A Schottky diode or similar. I cannot find a
supplier. What is special about a Schottky diode? Can I use smaller diodes
wired in parallel?
R
...Mosfet driver inverting/non-inverting questions.
2007-12-04 04:31:00
Hello,
I have am a little confused here about the inverting and non-inverting
mosfet drivers TC4429 and TC4420.
*********************************
From the Microchip datasheet:
The TC4429 is an inverting driver (pin-compatible
with the TC429), while the TC4420 is a non-inverting driver.
...mosfet gate threshold voltage
2008-10-24 19:18:00
http://www.powerdesigners.com/InfoWeb/design_center/articles/MOSFETs/mosfets.shtm
says:
4.5 Gate Threshold Voltage, VT , {VTH , VGS(th) }
VT is the minimum gate voltage at which the transistor will turn
ON.
Does this mean, 100% full ON? Or that the gate is Starting to turn On
(1% ON, ...About P-MOSFET
2006-09-21 03:05:00
I want to ask about making P-MOSFET:
1) the materials i use for making field oxide and the material i use
for making gate oxide, both must be used in the same materials? i mean
that in field oxide, i use silicon dioxide and in gate oxide, i do not
use silicon dixoide, can do that?
2) for th...mosfet? transistor? hexfet?
2006-12-21 14:46:00
When would one use a transistor? mosfet? hexfet?
Basically looking into PWM switching of medium-sized DC motors (12V,
~5A or so).
Which should I use...? A beefy transistor like a TIP36C? Or a hexfet
like IRLZ34NPBF (98c at Mouser)?
Thanks...
Michael
...MOSFET: current sources versus voltage sources that drives the gates of mosfet
peter - 2009-07-16 14:01:00
Hello,
Whats the difference if we have current sources that drives the gates
of mosfet versus voltage sources ??
Thanks in advance,
Su
...Inverter improvements?
lerameur - 2008-08-28 09:39:00
Hello,
I have an inverter circuit, although I learn that hooking a load
directly to its output is not working.
I was not sure if I should use an opAmp or mosfet, I have the circuit
below, any improvment? anybetter way to do it. The load I want to add
is to drive a mosfet
Yes some people will...Mosfet as a 12V Switch (and opto)
ProgrammerChicago@gmail.com - 2007-10-07 12:46:00
I've been stuck on this for awhile. I've got a MOSFET that is not
behaving the way I expect.
I was hoping it would act similar to the following animation where
source to drain is controlled by the gate:
http://www-g.eng.cam.ac.uk/mmg/teaching/linearcircuits/mosfet.html
But when applying 12...Does current flow when Vds is negative in power mosfets?
kyujin - 2006-10-04 17:09:00
I'm asking this question, because of the diode in the MOSFET models.
I know these diodes are to prevent spikes, but looking at it, makes me
wonder.
If Vsource > Vdrain by say 20Volts, can a current flow through the
MOSFET even if the gate is not turned on?
This would be a reverse current I gue...mosfet as switch
lerameur - 2008-08-16 18:26:00
hi,
I have two 12v batteries which I am hooking up in parallel using a
mechanical switch (via the ground).
I am attempting to swap the mechanical switch for a mosfet so I can
control them from a distance.
I tried to model in pspice but this is harder then I imagine. I tried
it experimentally...Re: Need help checking my power calculations
kell - 2006-09-05 10:46:00
Gerald wrote:
> Hi,
>
> I want to make a battery powered light, powered by a PIC.
>
> I have a rechargable 6.6 volt battery, and a 5 watt halogen bulb.
>
> Now, if I use a PIC and pulse the bulb at about 50% to get a dimmer
> output, is it safe to guess that I would get about 6 hou...Re: Need help with a MOSFET electronic load
amdx - 2008-11-04 14:31:00
wrote in message
news:285bdab7-5093-4e2f-831b-9fe115c68a65@x1g2000prh.googlegroups.com...
> I have been looking at some electronic load circuits. I would like to
> have a circuit that uses a MOSFET that pretends it is a high wattage
> fixed resistor. My application is a homemade RC rel...Re: DC Motors
Phil Allison - 2007-05-27 22:20:00
"Chris"
>
> http://www.cpemma.co.uk/pwm.html
>
> The "A Practical PWM Circuit" toward the top of the page will work
> well for a cordless motor requiring several amps DC.
** It will need two additional things to do that job:
1. A diode across the motor, rated for 7 amps or mo...synchronous rectification/current limiting
kell - 2007-07-22 12:22:00
I wanted a synchronous recitifier for a voltage regulator in an old-
style dc generator on an antique truck (to block the battery from
discharging into the generator).
This is what I came up with. I built it on a breadboard with junkbox
parts:
For the battery under charge used a junk motorcycl...MOSFET as a switch and Rds(on)
eliben - 2009-07-14 22:33:00
Hello,
I'm having a slight confusion over what Rds(on) means for a MOSFET.
In the book it says that Rds(on) is the resistance (Vds / Ids) in the
linear (triode) region. After the FET enters saturation, the
resistance obviously changes as the current stays the same for
increasing voltage.
...Re: Joule Thief - still not working....
Jon Kirwan - 2009-07-26 17:20:00
On Sun, 26 Jul 2009 13:08:45 -0700, John wrote:
>
> A TinyLogic schmitt trigger and a SOT-23 mosfet will make a nice
> controllable-PWM boost thing. It only needs a 2-terminal inductor,
> which simplifies life.
Um. SOT-23. I'm sure the OP will enjoy wiring that up -- if he
doesn't sne...will this work?
tempus fugit - 2007-01-05 19:34:00
Hey all;
I'm trying to design a circuit that will ground a signal when the control
voltage is applied, like this:
signal
o
|
...Re: how to make an active fuse
gearhead - 2009-04-17 16:22:00
On Apr 16, 4:51=A0pm, panfilero wrote:
> Hello,
>
> Can anyone suggest a way to make an active fuse using very few
> components? =A0I'd like an electronic fuse that opens after... say 5A or
> 10A.... I'm thinking about using a comparators and a solid state
> relay.... but I'm having t...Re: Delayed-off circuit
ehsjr - 2007-01-24 00:17:00
Randy Day wrote:
> I'd like to build a circuit to turn off
> some of the equipment on my fish tank for
> maybe 10 minutes during feeding time.
>
> Is there a low-parts-count circuit I can
> build to shut off AC power to a socket
> for that amount of time when I push a
> button?
> ...switching mosfet fully
kell - 2006-11-27 11:07:00
Dimmer circuit for dc?
12v
|
|
,---------------------+------------+-------+
| | | |
| 10K ...MOSFETs and PWM
Randy Day - 2007-02-24 13:05:00
I've built some TTL motor/relay controllers
out of NPN transistors in a Darlington
configuration, and I'm considering using
mosfets instead.
+V
|_
- )|
^ )| relay
|_)|
|
...Re: brushed pwm controller motor
Jasen Betts - 2009-01-02 05:02:00
On 2009-01-01, causalitist wrote:
> i put a 220 OHM gate resistor on the mosfets and it works great. gave the
> lm324 its little 12v source. ran 60v 20amps through the mosfets and the
> motor responded very well (linearly and smoothly) to the speed adjustment.
>
> thing is, i have no id...Re: IO mos
Rich Grise - 2006-09-30 15:46:00
On Fri, 29 Sep 2006 09:50:18 -0700, jason wrote:
> Dear All
>
> Can you share with me what is the major difference between a logic mos
> and I/O mos?
> Does IO mos has longer gate length or thicker gate oxide or longer
> width...?
> Kindly share with me some idea.
> Thank you All
...p-channel mosfet basic question
Dave - 2006-10-23 22:22:00
Hi all -
I've got a 2N5462 device that I'm trying to set up as a basic high-side
switch. I just want to turn on an LED to show the basic circuit connection
and have the MOSFET swtich it on and off with a toggle switch on the gate.
I connected the source to a +5VDC source, the gate through ...problem with grounds
lerameur - 2008-09-20 20:21:00
Hello
I posted a simple circuit up on
http://www3.sympatico.ca/captoro/motor/design1.gif
I am having difficulty seperating the grounds. My final circuit is
much more complex, it may look trivial at first, but I absolutely need
to seperate the grounds. IN the simulator they are the same ground...Here's a development one can use - for AC/DC power control
default - 2006-10-30 19:06:00
http://www.alliedelec.com/Images/Products/Datasheets/BM/AROMAT/Aromat_Industrial-Control_7880258.pdf
This is one of the new crop of mosfet drivers. A chip that takes
enough power (or about 1/6th) to light an LED.
The chip incorporates a series of photovoltaic diodes (in series) that
are il...Basic MOSFET Q., Also, "ground" vs "positive", & voltage matching
Kris Krieger - 2009-05-24 15:26:00
Hi, All!,
I have three questions.
First (and prob. "dumbest" ;) ) Q. -
I was looking at this page:
http://www.reuk.co.uk/DC-Voltage-Multiplier-Circuit-Plans.htm
and, in the section titled "3.3V Output from MAXC756", it says:
"By changing the input to pin 2 of the MAX756 from ground to posi...Re: Help needed with basic transistor assumptions
Bill Bowden - 2008-02-13 23:55:00
On Feb 13, 11:41=A0am, misterroy wrote:
> Hi, I'm a high school teacher and I've been working on a transistor
> revision sheet for my students. I'd appreciate any comments on the
> sheet I have made. Its at:
>
> http://docs.google.com/View?docID=3Ddg57p3md_27hjs34bgc&revision=3D_latest=...Re: MOSFET acting weird, any ideas?
Tim Wescott - 2008-07-22 17:25:00
thsuper1 wrote:
> On Jul 22, 2:33 pm, Tim Wescott wrote:
> > thsup...@gmail.com wrote:
> > > Hi all!
> > > Not a newbie, here, I went to electronics school about a decade ago,
> > > and although I've reeducated myself to this point, I seem to be stuck.
> > > Please help, anybody!
> >...Reading MOSFET SOA graph?
John - 2007-05-17 06:42:00
I need a reality check here. :-)
Am I reading the FBSOA graph (Fig. 11) correctly for this IXYS MOSFET?
http://ixdev.ixys.com/DataSheet/99022.pdf
It looks if I wanted to use it as a 100% duty-cycle switch (on for
seconds to minutes at a time), I'm limited to a Vds of about 25V?
Even if my ...Mosfet switch issues
Jon Slaughter - 2007-10-30 16:18:00
I setup a mosfet to switch power to a pin on a PIC. The circuit works only
for low R.
Vcc ---> R ----> Drain + link to pic
Source ---> GND
Parallel port --> Gate
Gate voltage is about 3.5-4.5V.
Everything works fine with R about 2k but with 4.7k or higher it does not.
Vcc is 5V....Re: Linear regulator
Jon Slaughter - 2009-11-20 01:15:00
Jonas wrote:
> On 19 Nov, 20:12, whit3rd wrote:
> > On Nov 19, 4:10 am, Jonas wrote:
> >
> > > Input signal, 24V PWM 400Hz
> > > I want to have 12V PWM signal 400Hz
> > > I was thinking of using a linear regulator (type LM317)
> >
> > An LM317 wants/needs 4 mA to bias normally;...