MOSFET TESTING

Started by Jessica Shaw in sci.electronics.basics5 years ago 4 replies

Hi, I am trying to test the following power MOSFET using digital multimeter. http://www.fairchildsemi.com/ds/FD%2FFDL100N50F.pdf I am...

Hi, I am trying to test the following power MOSFET using digital multimeter. http://www.fairchildsemi.com/ds/FD%2FFDL100N50F.pdf I am using the following way to do this http://in.answers.yahoo.com/question/index?qid=20061126230136AA6Blij But this MOSFET is showing anything. Its a new part. I tried another MOSFET (IRF540) and the test worked fine. I think that FDL100N50F has large...


mosfet driver needed for logic-level mosfets?

Started by Anonymous in sci.electronics.basics6 months ago 43 replies

Hello, I've discovered logic-level mosfets, and am using an Arduino to drive a small 12VDC (about an amp or so) pump motor with PWM, using an...

Hello, I've discovered logic-level mosfets, and am using an Arduino to drive a small 12VDC (about an amp or so) pump motor with PWM, using an IRLZ34N as the power mosfet. Would a mosfet-driver be recommended to switch that mosfet on and off more quickly? Or is a logic-level mosfet already designed to efficiently turn on and off with the weak logic level signal? Thanks, Michael


MOSFET: N- or P-, enhance or deplete?

Started by Bob Engelhardt in sci.electronics.basics4 months ago 35 replies

Here's really basic question for s.e.BASICS: I want to use a MOSFET to control a load, via a switch. The tricky part is that I need load...

Here's really basic question for s.e.BASICS: I want to use a MOSFET to control a load, via a switch. The tricky part is that I need load current when the switch is open and no current when the switch is closed. What I am confused about is what type of MOSFET to use, and its orientation in the circuit (S & D connected which way?) + | ...


Mosfet as a 12V Switch (and opto)

Started by Prog...@gmail.com in sci.electronics.basics10 years ago 8 replies

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...

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 12V between the source and the drain, my load (a light) slowly illuminates as if a capacitor is power...


Basic static electricity question

Started by M. Hamed in sci.electronics.basics3 years ago 8 replies

Let's say I walk over the carpet and get charged to 10KV. Then I touch a MOSFET. Is it fair to assume that the MOSFET won't be damaged unless...

Let's say I walk over the carpet and get charged to 10KV. Then I touch a MOSFET. Is it fair to assume that the MOSFET won't be damaged unless it has a path to ground?


DC motor pwm, mosfet barbecue, etc.

Started by Anonymous in sci.electronics.basics5 years ago 12 replies

Hi, I built a pwm circuit (200 Hz switching frequency) using 12V as a supply, also using around 12V to the gate of an IRF530 mosfet. I tested...

Hi, I built a pwm circuit (200 Hz switching frequency) using 12V as a supply, also using around 12V to the gate of an IRF530 mosfet. I tested it with an automotive turn signal light (about 1 amp) and it worked just fine (without a heat sink on the mosfet). I then tried using it to control a 12V tire inflator/compressor (about 4 amps). The inflator operated fine, but then when I felt the mo...


Driving a big LED with a MOSFET

Started by fungus in sci.electronics.basics5 years ago 40 replies

I'm trying to drive a big LED (3W) with a MOSFET. Eventually I want to drive it with an Arduino but so far I'm failing to get the right numbers...

I'm trying to drive a big LED (3W) with a MOSFET. Eventually I want to drive it with an Arduino but so far I'm failing to get the right numbers in my test circuit. My test circuit is like this: +5 | [R1] (8 Ohms) | D G -[R2]--- JUMPER S | LED | GND I can connect the jumper cable to +5V or ground and it switches on/off as expected. My MOSFET is one of th...


75332P MOSFET drain connected to which battery terminal?

Started by John Doe in sci.electronics.basics6 years ago 11 replies

I have a 75332P MOSFET on a cordless drill controller heatsink. I guess it's part of a pulse width modulator. The drain (flange) connects...

I have a 75332P MOSFET on a cordless drill controller heatsink. I guess it's part of a pulse width modulator. The drain (flange) connects directly to one of the battery terminals. Does the MOSFET drain go directly to the battery minus/ground terminal? Or does it go to the battery plus terminal? Thanks. -- My application... I'm desperately trying to develop a better inline ...


HF design approach

Started by lerameur in sci.electronics.basics4 years ago 16 replies

Hello to all, I am designing an amplifier for frequencies between 500khz to 5Mhz. (+/-40V= ) a couple of watts. I am a newbie to HF frequencies...

Hello to all, I am designing an amplifier for frequencies between 500khz to 5Mhz. (+/-40V= ) a couple of watts. I am a newbie to HF frequencies , but I would like to know what is the best= amplifier technique for these frequencies.=20 At first I wanted a pushed and pull mosfet driven by a mosfet driver, but t= he more I am looking the more i'm confused. I've seen some expensive specia= liz...


mosfet? transistor? hexfet?

Started by Anonymous in sci.electronics.basics11 years ago 11 replies

When would one use a transistor? mosfet? hexfet? Basically looking into PWM switching of medium-sized DC motors (12V, ~5A or so). Which...

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


Driving higher voltages with p-type MOSFET

Started by Anonymous in sci.electronics.basics5 years ago 28 replies

Hi guys: I'd like to control a 24Vdc load by sourcing with a p-type power MOSFET. I'= m driving the gate directly from a mictrocontroller that...

Hi guys: I'd like to control a 24Vdc load by sourcing with a p-type power MOSFET. I'= m driving the gate directly from a mictrocontroller that uses +5 and ground= . The problem is that I need +24 and +19. I looked into "high voltage level= translators", but they have been discontinued or are a non-stock item. Is there a simple, standard way that this is done? Thanks for any replies. ...


Does current flow when Vds is negative in power mosfets?

Started by kyujin in sci.electronics.basics11 years ago 3 replies

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...

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 guess. And if it does, how much? Normally there is a limit to Vds. but I'm wondering about the negativ


MOSFET as a switch and Rds(on)

Started by eliben in sci.electronics.basics8 years ago 3 replies

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...

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. However, people I ask say that they only use FETs for switching (i.e. either cutoff or saturation)...


Optically Coupled MOSFet ??

Started by Jim Thompson in sci.electronics.basics3 years ago 1 reply

Does anyone make an optically coupled MOSFet, Ron around 25 Ohms? All I can find are relay equivalent devices with loads of capacitance. ...

Does anyone make an optically coupled MOSFet, Ron around 25 Ohms? All I can find are relay equivalent devices with loads of capacitance. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | ...


mosfet as switch

Started by lerameur in sci.electronics.basics9 years ago 28 replies

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...

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, but when I hook up a iRFz44 , the batteries stays in parallel no matter the voltage in the base. ...


What does "high side" MOSFET driver mean ?

Started by Daku in sci.electronics.basics7 years ago 3 replies

Not being a power electronics person, could some electronics guru please explain the term "high side" MOSFET driver. Thanks in advance.

Not being a power electronics person, could some electronics guru please explain the term "high side" MOSFET driver. Thanks in advance.


Mosfet motor driver circuit advice

Started by Anonymous in sci.electronics.basics10 years ago 10 replies

Hello, An old project that I'd been working on is that of an electric fishing Kontiki. I have a circuit that I think will work O.K. but I hope...

Hello, An old project that I'd been working on is that of an electric fishing Kontiki. I have a circuit that I think will work O.K. but I hope that someone could take a look at it and point out any glaring mistakes. In particular the mosfet motor driver circuit is of concern to me. http://www.geocities.com/talionis.geo/Temp/temp.html The servo retract button and timeset reed switch are...


MOSFET switching an inductive, high-frequency load

Started by Don Gilmore in sci.electronics.basics4 years ago 8 replies

Guys: I'm an ME working on a project where I must switch voltage to a small coil = on and off at a fairly high frequency (around 25 kHz) with...

Guys: I'm an ME working on a project where I must switch voltage to a small coil = on and off at a fairly high frequency (around 25 kHz) with a MOSFET transis= tor. The DC resistance of the coil is very low (about 1 ohm), but the impe= dance is much higher because of the frequency (about 100 ohms). I'm switch= ing 24 Vdc. Should I specify the max. pulsed current of the transistor based...


Creating sparks with a mosfet and ignition coil

Started by Anonymous in sci.electronics.basics3 years ago 29 replies

I would like to generate a series of ~1000 volt sparks continuously, for several hours, using a spare automotive ignition coil I have lying...

I would like to generate a series of ~1000 volt sparks continuously, for several hours, using a spare automotive ignition coil I have lying around. I found this 555 circuit online: http://www.sci-experiments.com/HighVoltagePulser/ My questions: (1) Is a 500-volt MOSFET really necessary? Would a 100-volt IRF530 work alright without frying? (2) Does the 0.1 uF, 250V capacitor take the ...


Reading MOSFET SOA graph?

Started by John in sci.electronics.basics11 years ago 3 replies

I need a reality check here. :-) Am I reading the FBSOA graph (Fig. 11) correctly for this IXYS...

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 current level is low, say 1A? I've never seen the Vds rating drop with increasing pulse width befo...