Sound level detector circuit

[audioguru]

In other words it won't perform as well as the mosfet amp?

If you want the deer to wear your piezo tweeters on their ears then you can use the small very low power amplifier IC with tiny piezo speakers.
But the small amplifier IC probably cannot drive your large high power piezo tweeters.

What about the substitution of the FQP7P06 for the FQP17P06

The Mosfet that has a lower on-resistance does not heat as much but it has a higher capacitance that slows down its switching so it gets hot unless it is driven from a low resistance.

what ever forward transconductance is?

Transconductance is how much output current swing is caused by a low input voltage swing. It doesn't matter in your circuit because the Mosfets are switches, not linear amplifiers.

9.3S vers 4S
is this related to the capacitance you are referring to as to a reason the P channel gets warm?

It is one cause of heating.

 

[MrDEB]

Iam I to understand the the FQP17P06 will work better (concerning getting hot) than the FQP7P06 ?
My schematic is wrong in that it shows the FQP17P06
I think Mouser didn't have the FQP17P06 ?
And what the heck is trench technology as seen on the data sheet?
I emailed Maxium for suggestions but looks like I will be putting the mosfets on the outside using a right angle female header on the PCboard then just plug in the TO-220 mosfets. Add heat-sinks attached to the enclosure. A dab of silicone to weather proof.

 

[MrDEB]

another suggestion was suggested=add a couple of diodes as per
**broken link removed**
will give it a try.

 

[audioguru]

Don't add the diodes. They are too slow and will add a load to the Mosfets.
The diodes are used to arrest the voltage spike produced by an inductance (the motor) when it is turned off.
Your piezo tweeters have no inductance so they do not produce voltage spikes.