MOSFET Properties - Turning On/Off with 2n7000

  • Thread starter Thread starter Kerso1991
  • Start date Start date
  • Tags Tags
    Mosfet Properties
AI Thread Summary
The discussion centers on the behavior of the 2N7000 MOSFET, specifically regarding its ability to turn off when the gate is set to 0V. Users report needing to wait for the MOSFET to turn off or applying negative voltage to maintain the off state, raising questions about whether this is typical behavior or indicative of a faulty component. It is suggested that improper grounding or floating gate connections might be contributing to the issue, emphasizing the importance of correct wiring and grounding in the circuit. Additionally, the high input impedance of the gate can make the MOSFET susceptible to damage during handling. Proper circuit design and verification of connections are crucial for reliable operation.
Kerso1991
Messages
7
Reaction score
0
Hiya, I've been mucking around with a 2n7000 MOSFET and I can successfully turn it on and off, but to turn it off I either have to put the gate at 0v and wait a few seconds and it turns off itself or apply negative voltage to the gate and it'll stay off when I return it to 0v. Is this normal for MOSFETs or for even just FETs? Or is this just a dodgy MOSFET? Because as far as I know the MOSFET should turn off at 0v at the gate
Any help would be great
 
Engineering news on Phys.org
How are you changing the voltage on the gate? Does the 0V reference point (GND) of the controlling circuit have a DC connection to the source of the FET? The switching of the FET requires charging and discharging of some capacitance inside the device.

I had a similar experience debugging a circuit I put together. I forgot to wire all of my grounds together. As I recall, the FET was a 2N7000.

BoB
 
Kerso1991 said:
Hiya, I've been mucking around with a 2n7000 MOSFET and I can successfully turn it on and off, but to turn it off I either have to put the gate at 0v and wait a few seconds and it turns off itself or apply negative voltage to the gate and it'll stay off when I return it to 0v. Is this normal for MOSFETs or for even just FETs? Or is this just a dodgy MOSFET? Because as far as I know the MOSFET should turn off at 0v at the gate
Any help would be great

You have connected the source to 0V, a large resistor between the gate and the source and a 1k resistor from the drain to +5V? Your problems seem to me as if the gate is floating...

Check the pinout and your wiring again. Possible problem: Because of the extremely high input impedance at the gate, it is very easy to destroy a MOSFET just by handling it.
 

Thread 'Underwater piezoelectric sensor array receive sensitivity'

Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
View full post »

Thread 'Following up on the recent thread about Earth Resistance measurements'

I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
View full post »

Thread 'Question about bonding ground and neutral'

I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
View full post »

Similar threads

Parallel MOSFET safety diagnostics circuit
Replies
1
Views
2K
Bidirectional current switching with single type transistor
Replies
42
Views
5K
Mosfet SSR, flyback shunt/crowbar safety circuit
Replies
1
Views
2K
Looking for the right MOSFET transistor
Replies
6
Views
1K
Simple understanding of mosfets
Replies
6
Views
1K
MOSFET switching loss from datasheet parameters
Replies
1
Views
3K
ESD Safety of 2N7000 MOSFETs for Home Experimentation
Replies
3
Views
6K
How to switch on and off capacitance on a piece of conducting material?
Replies
10
Views
2K
Is there a snubber circuit for SEPIC converter to solve MOSFET turn-off issue?
Replies
3
Views
2K
High power switching circuit problem.
Replies
7
Views
3K

Hot Threads

Recent Insights

Back
Top