Like this..View attachment 291790

But you will lose probably 4V across the MOSFET and dissipate a lot of power, depending on the current.

If you want to use a follower, use a BJT, you only lose 0.7V then.

But a p-channel is far better.

 

i would like that the PWM will be on the positive.

Can I ask why? A PWM waveform can be 'inverted' by simply changing the duty cycle from x% to (100-x)%.
Do you have a schematic showing how/where this module is going to control the battery charger? I would expect the duty cycle to change automatically on the fly for control, but your module has buttons for manually changing the duty cycle.

 

Can I ask why? A PWM waveform can be 'inverted' by simply changing the duty cycle from x% to (100-x)%.
Do you have a schematic showing how/where this module is going to control the battery charger? I would expect the duty cycle to change automatically on the fly for control, but your module has buttons for manually changing the duty cycle.

It's a pre bought module with a pull up resistor to positive and open collector output, he wants a positive output with ground connection, so i suggested an external Mosfet or bjt, there is a % control on the module but i don't know if it's any use for him.

 

I have a battery charger for an electric vehicle. The battery charger need a pwm to charge the battery. the duty-cycle is needet in order to change the voltage. since the controller is missing I'm just trying to charge them with this circuit. Obviously I must stay there to supervise the voltage during the Charging time. I need to do this job once then the vehicle will be removed. But now I'm confused there's many solutions and I'm not able to chose. I was thinking it's was more easy.

 

I have a battery charger for an electric vehicle. The battery charger need a pwm to charge the battery. the duty-cycle is needet in order to change the voltage

Are you sure? This sounds highly unlikely. Do you have any info about this device?

 

here it is

 

It is not controlling voltage, as you stated, it is controlling power output.

 

yes, you'r right. Anyway this is the only way to control this charger. So, please advice me which solutions is best for me?

 

I can't say which option is best for you, but if the module does in fact produce the PWM output on the low side I would go with this.

 

ok thank you.
May I use this STD30NF06LAG?

 

No, that's NMOS use the one in post #12.

 

ok thank you.
May I use this STD30NF06LAG?

You need a P type like this..

https://cpc.farnell.com/on-semiconductor/fqp27p06/mosfet-p-to-220/dp/SC08209?st=Mosfet

 

You need a P type like this..

do you think the one in post #12 is wrong type? I choose it because I have some.

 

As long as it is a P type it's okay.