Inverter improvements?

L

lerameur

Guest
Hello,

I have an inverter circuit, although I learn that hooking a load
directly to its output is not working.
I was not sure if I should use an opAmp or mosfet, I have the circuit
below, any improvment? anybetter way to do it. The load I want to add
is to drive a mosfet
Yes some people will say not to use the same power supply on both
sides of the optocouplers ,but this is just for the simulation.

http://picasaweb.google.com/Kronmaster/ElectronicMisc/photo#5239559852433461314
 
lerameur wrote:
Hello,

I have an inverter circuit, although I learn that hooking a load
directly to its output is not working.
I was not sure if I should use an opAmp or mosfet, I have the circuit
below, any improvment? anybetter way to do it. The load I want to add
is to drive a mosfet
Yes some people will say not to use the same power supply on both
sides of the optocouplers ,but this is just for the simulation.
Click to expand...
Your complementary mosfets are not a very good way to
translate a 5 volt logic signal to a 6 volt LED drive.

That is a lot of parts to turn on one coupler when the logic
input is high and the other one when it is low. Or am I
missing some other intended function?

I think I would use an NPN follower to drive one coupler
through a 270 ohm resistor to the negative side of the 5
volt logic supply and a PNP follower to drive the other one
through a 270 ohm resistor to the positive side of the 5
volt logic supply. Those two transistors and two resistors
replace everything on the schematic except the couplers and
the output resistors.

http://picasaweb.google.com/Kronmaster/ElectronicMisc/photo#5239559852433461314
Click to expand...

--
Regards,

John Popelish
 
lerameur wrote:

I will be driving this from a microcontroller, I could not get a good
software approach, to get the duty cycle synchronyse. It is better to
do it hardware. I might make the output of the micro drive a 2n2222 to
activate the opto, then I will have to find a solution to control the
other opto.
Click to expand...
I don't understand "to get the duty cycle synchronyse".

Exactly what do you want the two gate signals to do?

Are you after 50% duty cycle except that the two MOSFETs not
overlap their conduction? Or do you need variable duty
cycle on each gate (either with the sum of their duty cycles
adding up to 100% or with equal duty cycles with variable
dead time when neither gate is on?

I don't know your design goals, so it is difficult for me to
give advice.

--
Regards,

John Popelish
 
On 8ÔÂ28ČŐ, ĎÂÎç9Ęą39ˇÖ, lerameur <leram...@yahoo.com> wrote:
Hello,

I have an inverter circuit, although I learn that hooking a load
directly to its output is not working.
I was not sure if I should use an opAmp or mosfet, I have the circuit
below, any improvment? anybetter way to do it. The load I want to add
is to drive a mosfet
Yes some people will say not to use the same power supply on both
sides of the optocouplers ,but this is just for the simulation.

http://picasaweb.google.com/Kronmaster/ElectronicMisc/photo#523955985
your simulation is ok?
Click to expand...
 
On Aug 28, 10:30 am, "cope2...@gmail.com" <cope2...@gmail.com> wrote:
On 8ÔÂ28ČŐ, ĎÂÎç9Ęą39ˇÖ, lerameur <leram...@yahoo..com> wrote:> Hello,

I have an inverter circuit, although I learn that hooking a load
directly to its output is not working.
I was not sure if I should use an opAmp or mosfet, I have the circuit
below, any improvment? anybetter way to do it. The load I want to add
is to drive a mosfet
Yes some people will say not to use the same power supply on both
sides of the optocouplers ,but this is just for the simulation.

http://picasaweb.google.com/Kronmaster/ElectronicMisc/photo#523955985

your simulation is ok?
Click to expand...
yep, turn on and off the 5v supply on the left and the assigned mosfet
turns on and off. I posted the same circuit twice with the two
possible conditions.
to show that is works. Is there a way to reduce the current that goes
into the opto? without affecting the output, maybe replace the opto...

K
 
On Aug 28, 11:40 am, John Popelish <jpopel...@rica.net> wrote:
lerameur wrote:
Hello,

I have an inverter circuit, although I learn that hooking a load
directly to its output is not working.
I was not sure if I should use an opAmp or mosfet, I have the circuit
below, any improvment? anybetter way to do it. The load I want to add
is to drive a mosfet
Yes some people will say not to use the same power supply on both
sides of the optocouplers ,but  this is just for the simulation.

Your complementary mosfets are not a very good way to
translate a 5 volt logic signal to a 6 volt LED drive.

That is a lot of parts to turn on one coupler when the logic
input is high and the other one when it is low.  Or am I
missing some other intended function?
Click to expand...
I will be driving this from a microcontroller, I could not get a good
software approach, to get the duty cycle synchronyse. It is better to
do it hardware. I might make the output of the micro drive a 2n2222 to
activate the opto, then I will have to find a solution to control the
other opto.

k
 
On Aug 28, 11:58 am, John Popelish <jpopel...@rica.net> wrote:
lerameur wrote:
I will be driving this from a microcontroller, I could not get a good
software approach, to get the duty cycle synchronyse. It is better to
do it hardware. I might make the output of the micro drive a 2n2222 to
activate the opto, then I will have to find a solution to control the
other opto.

I don't understand "to get the duty cycle synchronyse".

Exactly what do you want the two gate signals to do?

Are you after 50% duty cycle except that the two MOSFETs not
overlap their conduction?  Or do you need variable duty
cycle on each gate (either with the sum of their duty cycles
adding up to 100% or with equal duty cycles with variable
dead time when neither gate is on?

I don't know your design goals, so it is difficult for me to
give advice.

--
Regards,

John Popelish
Click to expand...
I just need 50%, one mosfet turns on the first half and the other
turns on the other 50%, therefore always one turned on.
(In a microcontroller I could not get only the second half to
activate)

Ken
 
On Aug 28, 1:11 pm, lerameur <leram...@yahoo.com> wrote:
On Aug 28, 11:58 am, John Popelish <jpopel...@rica.net> wrote:



lerameur wrote:
I will be driving this from a microcontroller, I could not get a good
software approach, to get the duty cycle synchronyse. It is better to
do it hardware. I might make the output of the micro drive a 2n2222 to
activate the opto, then I will have to find a solution to control the
other opto.

I don't understand "to get the duty cycle synchronyse".

Exactly what do you want the two gate signals to do?

Are you after 50% duty cycle except that the two MOSFETs not
overlap their conduction?  Or do you need variable duty
cycle on each gate (either with the sum of their duty cycles
adding up to 100% or with equal duty cycles with variable
dead time when neither gate is on?

I don't know your design goals, so it is difficult for me to
give advice.

--
Regards,

John Popelish

I just need 50%, one mosfet turns on the first half and the other
turns on the other 50%, therefore always one turned on.
(In a microcontroller I could not get only the second half to
activate)

Ken
Click to expand...
Ok I added it anyway:
http://picasaweb.google.com/Kronmaster/ElectronicMisc/photo#5239620205668067362

K
 
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