op amp comparator circuit - Page 2 - Electronic Circuits Projects Diagrams Free

ericgibbs · 24th October 2009, 12:42 PM

Quote:

Originally Posted by MrDEB

in order for relay to energize
hope I got this right??

hi,
Under what conditions do you want the relay to be energised.?

Please post your asc file.

Mikebits · 24th October 2009, 12:42 PM

Quote:

Originally Posted by ericgibbs

Why do you think you are offending me.

Like you I dont not know for sure what the OP wants to do.

I assumed that the mention of two diodes would start bells ringing in MrDebs head, as a possible solution.

In the end, your solution seems to be good one, was not trying to jab you, ya know I luv ya man.

MrDEB · 24th October 2009, 02:57 PM

hope this works

MrDEB · 24th October 2009, 03:03 PM

it works in simulation

ericgibbs · 24th October 2009, 03:18 PM

Quote:

Originally Posted by MrDEB

it works in simulation

hi,
Look at these two modified asc.

When is the battery monitor supposed to switch on/out.?

MrAl · 24th October 2009, 03:23 PM

Quote:

Originally Posted by Mikebits

Not quite, two diodes reversed bias with pullup will make And gate.

Hi Mike,

Well Mike, that's your version. Mine uses three :-)

I was going to use a third diode just to make sure the
transistor turns off fully. With two diodes and pullup, there could
still be as much as 0.6v at the base of the transistor. With an
extra diode in series with the transistor base and a light pulldown
on the base, the transistor base sees about 0.15v and turns off
fully. Depending on load it may work anyway, but it could be close
without the extra diode, not something i would be comfortable with.
Another version would put the extra diode in series with the emitter
if power considerations allow.
Still yet another version could use an extra resistor to divide the
diode voltage down so the base sees about 1/2 a diode drop instead
of the whole diode drop.

That reply was a little joking too BTW :-)

MrDEB · 24th October 2009, 05:13 PM

hav'nt figured out how to use a pot (variastor) in spice.
and how do you get the triangle wave??
the monitor is supposed to be adjusted to close relay at around 10-11 volts
I played with it in spice as well as Tina (Tina dosn't have an op amp with single supply) but it still worked.
still trying to figure out all the little things in spice = multi planes, varistors, steeping through the battery voltages(change from 12 to 11 to 10 etc. to see the circuit in operation.
we is learning
will look at your sims and decipher. what did you change??

ericgibbs · 24th October 2009, 05:21 PM

Quote:

Originally Posted by MrDEB

hav'nt figured out how to use a pot (variastor) in spice.
Why not use the 'voltage' model and set the V range to suit
and how do you get the triangle wave??

Use the PWL piece wise list
You can see that list I entered,modify it to suit your app

the monitor is supposed to be adjusted to close relay at around 10-11 volts
I played with it in spice as well as Tina (Tina dosn't have an op amp with single supply) but it still worked.
still trying to figure out all the little things in spice = multi planes, varistors, steeping through the battery voltages(change from 12 to 11 to 10 etc. to see the circuit in operation.
we is learning
will look at your sims and decipher. what did you change??

hi,
If you have a query, please ask, post your asc file so that we can edit it and post it back, OK.?

LTSpice Tutorial

MrDEB · 24th October 2009, 05:30 PM

will try out the voltage model. need to locate first = lol

MrDEB · 24th October 2009, 05:39 PM

got it working
thanks
wondered what pwr was??

ericgibbs · 24th October 2009, 05:40 PM

Quote:

Originally Posted by MrDEB

will try out the voltage model. need to locate first = lol

On the schematic part press F2 key then select 'voltage'

MrDEB · 25th October 2009, 02:59 AM

couldn't get the relay to open using a PNP transistor
resorting to opticolupter
looks like it works??

MrDEB · 25th October 2009, 01:45 PM

trying to sim a simple relay being controlled by an op amp
got the LEDs to work but tried inserting a pnp transistor - nada
I figure the LED works so insert an opticoupler
still isn't right??
Getting really lost in Idaho
something so simple and run into a snow storm

ericgibbs · 25th October 2009, 02:23 PM

Quote:

Originally Posted by MrDEB

trying to sim a simple relay being controlled by an op amp
got the LEDs to work but tried inserting a pnp transistor - nada
I figure the LED works so insert an opticoupler
still isn't right??
Getting really lost in Idaho
something so simple and run into a snow storm

hi
Look at the V symbols... you have +v and v+..... they are different!!!!

Mikebits · 25th October 2009, 02:27 PM

Quote:

Originally Posted by ericgibbs

hi
Look at the V symbols... you have +v and v+..... they are different!!!!

Good eye Eric

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24th October 2009, 05:13 PM	#22
MrDEB	R6 and R7 is supposed to be a pot hav'nt figured out how to use a pot (variastor) in spice. and how do you get the triangle wave?? the monitor is supposed to be adjusted to close relay at around 10-11 volts I played with it in spice as well as Tina (Tina dosn't have an op amp with single supply) but it still worked. still trying to figure out all the little things in spice = multi planes, varistors, steeping through the battery voltages(change from 12 to 11 to 10 etc. to see the circuit in operation. we is learning will look at your sims and decipher. what did you change??

24th October 2009, 05:30 PM	#24
MrDEB	Thanks will try out the voltage model. need to locate first = lol

24th October 2009, 05:39 PM	#25
MrDEB	took out battery, inserted voltage got it working thanks wondered what pwr was??

25th October 2009, 02:59 AM	#27
MrDEB	I tried everything but!! couldn't get the relay to open using a PNP transistor resorting to opticolupter looks like it works?? Attached Thumbnails