Mosfet & Motors

[Bizzy]

Hi Carroll, here is one way that I use this type of sensor. When the sensor "see's the light", it sends a 5 volt signal to a input pin of the chip. I then have the chip "act on doing something if it see's that pin high. Example;

Symbol Sensor1 = pinC.6 ; Alias C.6 pin
Symbol Sensor2 = pinC.7 ; Alias C.7 pin

if Sensor2 = 1 then
pulsout B.6, 150
endif

The resistor's are 1K for R14, 15 and 330 for the others.

Hope this helps,

Bit's

Hi Bit
What is the purpose of the 2nd sensor? Is it triggered on the same shielding mechanism as the 1st sensor?
Thanks
Bizzy

[citfta]

Hi Bits

Hi Bits,

Good to hear from you again. These guys are just learning how to control mosfets so I was trying to keep it simple. Thanks to you and all your patience with me I have learned how to control motor speed using either a pot or feedback from the voltage of the generator. I use the PWM function of the chip for my output. I love that Picaxe 18x. So far it does all I need to do. In the schematic I posted near the start of the thread I am controlling the motor with a Pic.

I finally got all the parts in for the board you gave me but things have been very hectic here ever since Idaho. I have had several really bad colds and an attack of kidney stones. I think I am getting old (only 65). I don't know yet if I am going back to Idaho this year or not. I really want to but there is a lot going on here I can't post about. Thanks again for all the help you have given me over the past couple of years.

Guys this is one of the real gurus of electronics I have told you about. If it was not for him and Matt Jones and DoubleD and John Bedini and several others I would not be nearly as far along in this as I am.

See ya, Carroll

[Bit's-n-Bytes]

Hi Bit
What is the purpose of the 2nd sensor? Is it triggered on the same shielding mechanism as the 1st sensor?
Thanks
Bizzy

Hi Bizzy, No the second sensor is for another winding. You can just use one sensor if you like.

@Carroll, hope you can make it. Had a blast at the last one.


Bit's

[Bizzy]

Hi Bizzy, No the second sensor is for another winding. You can just use one sensor if you like.

@Carroll, hope you can make it. Had a blast at the last one.


Bit's

Hi Bit
Ok.
thanks!
Bizzy

[Bizzy]

is my mosfet working???

Good afternoon
I am still working on my Watson machine and and current working on installing the trigger devices. The trigger deivce is a magnet at the end of my rotor. When the magnet passes over the trigger coil it produces a small charge which it send s to the mosfet which will allow the motor to pulse.
My question is how can I tell if my mosfetr is actually working?
The rotor is going at such a high rate of speed, so i am not certain if it is pulsing but at a high rate or if it is simply remaining open. Is there something i can add to my mosfet circut to determine what is happening?
thanks
Bizzy

[Bizzy]

pulses???

I was able to solev my own problem by placing an analog amp meter between the motor and battery in my mosfet circuit. The needle bounced several times at the start of easch cycle to show pulsing but soon afterward the circuit remianed closed allowing the current to continuously flow into the motor. So now I must work on shorting the time the gate is closed.
Bizzy

[citfta]

Hi Bizzy,

Can you post a drawing of your circuit? I think I understand what you are doing. If you are using an analogue meter you may not be able to see the pulses once the motor gets up to speed. Most analogue meters have a dampener built into them to keep them from vibrating. This would keep you from seeing really quick pulses as the needle can't move that fast with the dampener trying to hold it steady. You may be able to use a LED and a voltage divider circuit and hold the LED near your trigger magnet and see if the motor is actually being pulsed in time with the magnet.

Carroll

[Bizzy]

circuit

Hi Carroll
Here is the circuit I am using for my pulses.
As you can see I have my AMP meter between my motor and the battery. I still have a feeling I am getting pulses but they may be happening so quickly I cant see them.
Any help you can give wold be greatly appreciated.
Bizzy

[Bit's-n-Bytes]

Hi Carroll
Here is the circuit I am using for my pulses.
As you can see I have my AMP meter between my motor and the battery. I still have a feeling I am getting pulses but they may be happening so quickly I cant see them.
Any help you can give wold be greatly appreciated.
Bizzy

Bizzy, (if I may) not sure of your total setup, but remove the cap on the gate.

Bit's

[Bizzy]

Bizzy, (if I may) not sure of your total setup, but remove the cap on the gate.

Bit's

Hi Bits
I have tried the circuit with and without the the rectifing capacitor. It appeared like I was getting the same results but as I mentioned before it moves so fast afterwards it is hard to tell. Originally I put the capacitor in to build up voltage coming off the coils. However with a little tweeking I dont really need it in the circuit and in fact I know in some cases it leaves the gate open longer which is why I put the resisitor in the series.
But sure I can remove going forward.
Thanks
Bizzy

[Bit's-n-Bytes]

Hi Bits
I have tried the circuit with and without the the rectifing capacitor. It appeared like I was getting the same results but as I mentioned before it moves so fast afterwards it is hard to tell. Originally I put the capacitor in to build up voltage coming off the coils. However with a little tweeking I dont really need it in the circuit and in fact I know in some cases it leaves the gate open longer which is why I put the resisitor in the series.
But sure I can remove going forward.
Thanks
Bizzy

Try setting it up this way.

Bit's

[Bizzy]

Try setting it up this way.

Bit's

Hi Bits
I understand the upper part of the schematic but cant follow the bottom portion. Could you explain that?
Thanks
Bizzy

[Bit's-n-Bytes]

Hi Bits
I understand the upper part of the schematic but cant follow the bottom portion. Could you explain that?
Thanks
Bizzy

H11d1 is an opto, pin 1 goes to your output pin of the triggering device. I. E a 555 would be pin 3, a PIC would be the output pin you choose. The resistor on pin 2 of this opto should be 100 to 330 Ohms. As depicted, a 15V source goes to pin 5 of the opto and when the opto is "pulsed", pin 4 connects this voltage to the gate of the FET. This isolates your source from the "business" side of the circuit.

Hope this helps

Bit's

[Bizzy]

H11d1 is an opto, pin 1 goes to your output pin of the triggering device. I. E a 555 would be pin 3, a PIC would be the output pin you choose. The resistor on pin 2 of this opto should be 100 to 330 Ohms. As depicted, a 15V source goes to pin 5 of the opto and when the opto is "pulsed", pin 4 connects this voltage to the gate of the FET. This isolates your source from the "business" side of the circuit.

Hope this helps

Bit's

Hi Bits
Ok Thanks for explaining your diagram. I havent delved into 555 circuits yet although if the issues still remain I may have to
Thanks
Bizzy

[Bizzy]

H11d1 is an opto, pin 1 goes to your output pin of the triggering device. I. E a 555 would be pin 3, a PIC would be the output pin you choose. The resistor on pin 2 of this opto should be 100 to 330 Ohms. As depicted, a 15V source goes to pin 5 of the opto and when the opto is "pulsed", pin 4 connects this voltage to the gate of the FET. This isolates your source from the "business" side of the circuit.

Hope this helps

Bit's

Hi Bit
Thanks for suggesting using a 555 chip. It is requiring a lot more studying and experimenting but I think in the end it will be worth it...


I do however have anothoer mosfet question I hope you or someone else can answer.
I have successly been able to hook up and use N channel mosfets...are P Channels mosfets hooked up to the ciruit in the same way?
Thanks
Bizzy