hello, i designed simple circuit.




but i can't turnning off

i tried Q9's Gate tobe 14~19V with zener diode beween Q9's gate and 24V+(Source).

should i add Resistor between Q9's gate and Q7's Collecto?

 

Your circuit applies 24V across the gate and source of the MOSFET which is OK as long as the 24V is accurate and stable - the maximum allowed is 25V.
When the MOSFET should be off without the zener, what is the voltage between gate and source?

 

Q9's Gate - GND = 21V

i'm trying to change R32 to 1K, 2.2K, ...100K

 

Q9's Gate - GND = 21V

I am interested in gate to source voltage though.

 

but still i can't turning off

Relay_1_ON/OFF signal is fine 5v

 

I am interested in gate to source voltage though.

source is 23.27V

 

That is because of the zener which is limiting the gate to source voltage. Remove the zener and measure that voltage and see whether the MOSFET does turn off.

 

That is because of the zener which is limiting the gate to source voltage. Remove the zener and measure that voltage and see whether the MOSFET does turn off.

i removed but still ..not working

 

i removed but still ..not working

What is the voltage between gate and source when the MOSFET should be off.

 

What is the voltage between gate and source when the MOSFET should be off.

when board turn-on Relay_1_Coil don't turning off

Q7's gate is 1.8V

Q9's gate is 17V

removed diode but same

 

Q7's gate is 1.8V

Q7 doesn't have a gate. Do you mean base or collector?

 

Q9's Gate - GND = 21V

i'm trying to change R32 to 1K, 2.2K, ...100K

There is NO R32 on your schematic!
Why do you not understand how to measure and report the GATE TO SOURCE voltage? This is NOT Gate to Ground or Source to Ground but GATE with respect to the SOURCE.

 

Q7 doesn't have a gate. Do you mean base or collector?

Gate, Base, voobah whizz bang. What difference does it make?

 

Gate, Base, voobah whizz bang. What difference does it make?

There is NO R32 on your schematic!
Why do you not understand how to measure and report the GATE TO SOURCE voltage? This is NOT Gate to Ground or Source to Ground but GATE with respect to the SOURCE.

i tried to measure and i just blowed it.


it was about 5.8V


I have to solder a new board

 

i tried to measure and i just blowed it.


it was about 5.8V


I have to solder a new board

It sounds like you are having a very bad day. Sorry to hear that.

 

It sounds like you are having a very bad day. Sorry to hear that.

thank you!

I burned my hand while soldering andI drew Artwork incorrectly and wired 32pins. lol

 

thank you!

I burned my hand while soldering andI drew Artwork incorrectly and wired 32pins. lol

A good technician is worth every nickel, especially early in the morning.

 

A good technician is worth every nickel, especially early in the morning.

Thank you so much for your kind words!


I'll be back with good result

 

[SOLVED]




There was a problem with two parts.

1. D4(Zener diode)

- D4 should be Q9's G & S (NOT G & gnd)


2. My MCU's I/O pin was broken.

- I guess there was a short when I changed the resistance and diodes



Thank you to everyone who replied.
I hope people who see this post don't make stupid mistakes like me.


Have a nice day, everyone!

 

There is still a possible reliability problem with this circuit.
Consider what happens when Q7 is turned on. The zener means that the minimum collector voltage on Q7 is 9V (24V supply minus 15V zener). There is no current limit for the collector current. I suggest a resistor in the collector lead of Q7, perhaps 680Ω. This will limit the collector current without harming the operation of the circuit.