12v battery/transformer question.

[cbiblis]

Hopefully you're not going into production with a design that almost works.[/QUOTE]

I didn't design this circuit. Mikeim did. And he has been right on the money all the way through when it comes to his designs, he is an electronics engineer and he to has an excellent rating. It was my changes that caused the problems. And i didn't say that it almost works, i said that it works completely now. I did take the 1n4148's out of the circuit and I'm using a full bridge rectifier in there place. It works 100% now. I am setting 36 eggs today in 21 days if i have a 95-100% hatch rate then it is perfect, i will test for another 2 runs of eggs @ 21 days. Then i will average the hatch rates. Then if except able i will start production.

 

[cbiblis]

The P-channel Mosfet is a follower. When its gate goes to ground then its source will be at about +10V, not 0V. Then the motor gets only 2V.
Use an N-channel Mosfet with its drain driving the motor wire to 0V.

The MTP23P06 to my understanding is a n-fet. As for it's connection i don't know for sure but i put it in the direction that eagle set on the .brd from the sch file and it works. There are some discrepancies from what the circuit is suppose to do vs what it is actually doing. The 4 minute time off is actually 2:18 and the 10v-1v is actually 12v-7v but 7v seems to work very well for the timeing that i need for a full rotation in 1 minute. This might be where the 6.8m to 2.2m comes in but i haven't learn all of the resistance factors yet. I just started learning electronics about a month or two ago in my spare time.

 

[audioguru]

The MTP23P06 to my understanding is a n-fet.

No.
It is an ordinary P-channel Mosfet that needs a fairly high gate voltage (10V) to turn on.

Mike used a logic-level P-channel mosfet that needs a fairly low gate voltage (2.7V to 4.5V) to turn on so he made his a follower and shows the motor getting only 3.7V.

Mike also used a DC power supply. Without at least a 1000uF filter capacitor then your supply is bouncing with the AC from your transformer.

Your circuit is very different to Mike's.

 

[cbiblis]

I do realize that my alterations made his circuit change that's why i needed help fixing it. Sorry to stir the bees nest.

 

[audioguru]

Then use the Mosfets that Mike selected.
Your different Mosfets would need a different circuit.

 

[cbiblis]

Then use the Mosfets that Mike selected.
Your different Mosfets would need a different circuit.

Thanks for the advise.

 

[MikeMl]

Then use the Mosfets that Mike selected.
Your different Mosfets would need a different circuit.

I wasn't following this thread. Cibilis wanted to reduce the motor drive voltage to ~3V, starting from a 12V supply, so the FET is a PFet, configured as a source follower. Since the duty cycle and motor current is low, the heatsinking requirement is modest.