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thank you goldsmith and Brian. Makes perfect sense.
I chose a logic level MOSFET so it would be in the full on Vgs region most of the time.
I'll lower the gate resistor and get a Schottky in there. The 1N4002 is working but I don't like heat. Do I need a Gate resistor? What is the advantage...
In my other/related thread I had asked if a larger PWM input to Gate Series resistor value would slow down the start current or give a softer startup for the MOSFET. I'm wanting to protect the MOSFET upon initial startups.
Also... in my question regarding the Schottky diode, how would I choose...
Schematic Posted. This was my first use of Eagle so I'm not sure everything is "correct" but that should be the idea.
I'm using PWM because I need to control a valve varied by voltage to the solenoid. I believe the frequency is 1kHz
So I'm guessing a Shottky would be up to speed as far as...
I have a MOSFET driving a solenoid (6 ohm load running at 3-5 Volts PWM) and I notice if I disconnect the load and reconnect it I get a spark and at times burn out the MOSFET (logic and rated at 4A). Is there a way to soften the startup? I'm obviously not going to be disconnecting and...
I have PWM running a solenoid at approx 3.5V from 10-12V DC as a reference. I have a SMT MOSFET (IRLML6246TRPBF) rated at 20V and 4.1A driving the solenoid (measures 6 ohms).
Here's something I know nothing about and have two questions.
1. If I don't have the flyback diode in circuit...
I have tried to get 4V at 1A from a 12-14V source and the regulator is getting pretty hot (LM317). It seems like the data sheet said it could supply 1.5A. But I guess that's also up to an 10V*1A=10W power dissipation in the regulator.
Is there a better way to do what I'm trying to do here?
I...
This is why I was thinking a low Vgs would be good. Some need 12V to fully conduct and logic level MOSFETs only need maybe 3-4 V to be fully on.
I'm guessing (hopefully) this would eliminate the need for a driver?
Great. Would I want a Logic level MOSFET since I'm using a uC as the PWM source?
One thing I'm not sure of is how sensitive the gate needs to be. I wouldn't want the MOSFET to be full on with each pulse, would I?
I have a solenoid where I'd like to vary the current. I would guess since the solenoid's coil resistance is fixed that'd mean that I vary the voltage since:
V=IR
So what/how would I do this. I would guess it's going to be high current since the coils DC resistance is only 6 ohms.
Would PWM...
MOSFET's are pretty simple to operate as a switch. However it seems like to get the lowest Drain Source resistance the Gate voltage needs to be quite a bit higher than what most logic circuits can supply (in the range of 12V for Vgs). How would I do this using an NPN transistor between a...
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