i try to control a p mosfet via esp32
load is 42v 20mA
im using bss138 n-fet and bss84p-fet
but if u suggest to change i also have ilrml2502 and ilrml6402 that can use
if i measure with multimetter all is ok but problem appear when i add the load and try to turn it on then i see 14V insteand of 42v
What is the load resistance?
The BSS84 is a poor choice for a power switch, as the absolute maximum continuous drain current is only 130 mA.
i dont know if 46.8 mA or1.237A
if multimeter is in mA it works, if i switch to A then module that i try to start is not working
I repeat: what is the load resistance?
how can i measure
Use the multimeter to measure the load resistance, or tell us exactly what it is.
its a ignition wire for a blcd controller. so i need to connect that wire to Voltage to start the controller
That sounds wrong.
Post a link to the BLDC controller.
Your schematic looks OK to me. But the load you have connected might be way too much for your fets.
From what you are saying about the ammeter, consider that the ammeter has internal resistance and is significantly more when you measure in the mA range than when you measure in the A range.
Just a guess here but the A range might be a few mili ohms and the mA range might have a few ohms on it.
So this will affect the behaviour of your circuit.
Also, because the current measurement in both mA and A setting is significantly different, now I wonder what kind of load you got.
I guess your load is actually 1.237A, since it's an ignition coil.
What is the load specs you are trying to turn on?
like this but 36v
if i use ilrml2502 and ilrml6402 insteand of bss138 and bs84 do u think will do the job
No, their maximum voltage rating is too low. They are 20V.
Doing a quick search for P channel mosfets I came up with this IPD40DP06NMATMA1
Has 60Vds, Up to 4.3A, and same Vgs of 20V
Btw, just noticed another issue, you might want to change the value of R41so the Vgs is not too high for the mosfet.
Can't keep up with your cross-posts any more,
but in this thread (post#10) I already gave you the answer.
Leo..
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