You need a negative gate-source voltage (Vgs) to turn off a depletion mode N-MOSFET.
Depends upon the source voltage.Sorry, I don't know much about it. It requires Vgs of -2 to -4v. Does that mean I need to have Vg @ -9vdc?
Source voltage is 12.7vdc.Depends upon the source voltage.
.9a draw on MOSFET drainPlease post a schematic as 800x600 *.jpg, *.gif.
How much current draw?
You should choose another N MOSFET, because the Vdsx of IXTP3N50D2 is too high and that kind of type will be have a high Rds(1.5Ω), and the high Rds will causes a high voltage drop (Vds=Id * Rds), and that does not suit for your low voltage application.
N, P type MOSFET Components Simple Data.
According to your schematic, the source of M1 and M2 are connected to ground.Source voltage is 12.7vdc
Use enhancement-mode N-Mosfets. That circuit won't work with depletion-mode devices.Here is what I am trying to do, what should I do differently?
Yes that is my idea and it is one depletion MOSFET and one enhancement MOSFET.I'm still not clear on the objective. Are both the FETs supposed to be depletion mode or is one depletion and one enhancement, with the idea that the one LED is on when the 555 output is HIGH and the other when the 555 output is LOW?
Good catch.Are both the FETs supposed to be depletion mode or is one depletion and one enhancement, with the idea that the one LED is on when the 555 output is HIGH and the other when the 555 output is LOW?
OK, Thanks!Use enhancement-mode N-Mosfets. That circuit won't work with depletion-mode devices.
Reverse the direction of the LEDs.
Recalculate the resistor values for the LM317 (which is a voltage regulator, not a transistor as you show). R3 should be no larger than 120Ω.
Attached is a more readable copy of your circuit:
View attachment 147822
Inverter Circuit? Sorry, I don't know a lot about that.Good catch.
I didn't notice they were different.
So for that, there's a number of options.
On is to use two enhancement-mode N-MOSFETs with an inverter circuit in between.
Another is to use one enhancement-mode N-MOSFET and one enhancement-mode P-MOSFET.
It can be a common-emitter transistor circuit with a couple resistors, or a logic chip inverter, such as a CD4049.Inverter Circuit?
Ok, thanks for your helpIt can be a common-emitter transistor circuit with a couple resistors, or a logic chip inverter, such as a CD4049.
by Aaron Carman
by Duane Benson
by Jake Hertz