Driver to drive?

On Thursday, March 28, 2013 3:50:28 AM UTC+5:30, rickman wrote:

On 3/27/2013 3:43 PM, George Herold wrote:

On Mar 27, 2:06 pm, bhav....@gmail.com wrote:

The schematic at the link below is to control the enable pin of LM22680 regulator. It has enable pin pulled up internally, which means it is always ON. This circuit is to pull it to Low to disable. Logic is as follows.



Ignition ON detection threshold is approx 6V at ignition wire and low battery threshold is approx 9V at battery wire.



If (GPIO from MCU is '1' OR Ignition is ON) AND (Battery Voltage is above threshold), ENABLE is left floating to keep LM22680 ON

else keep it LOW to disable.



Q1 is ON when battery is above threshold (approx 9V) else OFF. Q2 will be ON when either GPIO OR Ignition is ON. When both Q1 and Q2 ON, Q3 will be OFF leaving Enable floating.(regulator is ON)



Thresholds are not very critical +/- 1V is fine. It works as expected in simulation. Is this fine in automotive environment? Any modifications?



Looks weird to me... how did you 'expect' it to work?

(Where does the power for Q1 and Q2 come from?)



Looks ok to me. I think the circuit works ok. The OP is likely asking

about special issues from using it in cars. A car electrical system is

a tough environment to design electronics for.



Power for the inputs of Q1 and Q2 are provided by their prospective

sources, the battery in one case and the MCU in the other. The power

for the collector is provided by R22, 100K from the battery.



As long at the transistors are rated for the extreme voltages that may

be found. For example, the BE junction of Q1 needs to survive a

negative transient through the two 1 kohm resistors. In that case I

think D5 is forward biased and R18 won't impact the circuit much. The

OP says "Both Battery and Ignition are reverse polarity, transient and

load dump protected." Not sure what that implies in terms of the

voltages the inputs will then see.





Both Battery and Ignition are reverse polarity, transient and load dump protected. Transients are clamped to 30V. Max continuous voltage is 16V. No 24V jump start protection needed.



https://picasaweb.google.com/106331244879972692887/December182012?aut...



--



Rick

Thanks. I said there is a reverse polarity protection diode, TVS diode to clamp the transients to 30V that are not shown in the schematic.

bhav

 

On Friday, March 29, 2013 5:01:02 PM UTC-4, John Larkin wrote:

When this 1 kVA unit is connected as an autotransformer for this voltage

combination, its kVA rating is increased to 9.58 kVA (may also be expressed

as 9,580 VA). This is the rating to be used for determining the full load

input amps and the sizing of the overcurrent protect device (fuse or breaker)

on the input.



The secondary of an autotransformer carries the load current but only

supplies the voltage *difference*. 240-208 is only 32 volts, so at 20

amps the boost secondary is delivering 640 VA.

Wiring the primary of 10:1 step-down across the line "pins" its secondary voltage at 10% line voltage. So obviously if that secondary is in series with the load it only delivers 10% of the load power with the line delivering the other 90%. If the max transformer KVA is X then the maximum load that can be safely driven is.... wait for it....wait for it... 10 x X. Makes no difference if it's buck or boost. But in boost mode, the line supplies 1.1 x Load current, and in buck mode it supplies 0.9 x Load current.

 

[Jim Thompson]

On Sat, 30 Mar 2013 14:15:00 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, March 29, 2013 11:17:28 PM UTC-4, Sylvia Else wrote:


You can look at it this way: All the input current flows through the

primary, and all the output current flows through both the primary and

the secondary. But the output current is in antiphase with the input

current, so most of the current in the primary is cancelled. The primary

has to handle only the difference between the input and output current.
Sylvia.

Huh? In boost mode , the transformer high side is the primary, and the low voltage side is secondary . In buck mode, the transformer low voltage side is the primary, the high voltage side is the secondary. In each case, transformer high voltage side current is 1/10 transformer load voltage side current. There's no looking at it this or that way, there's only comprehension of what a transformer is.

Now, now, Freddy! To fit in here you need to learn to treat the
ignorant in a politically correct manner >:-}

Otherwise it'll be your turn to be attacked and told to change your
diaper ;-)

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[DecadentLinuxUserNumeroUn]

On Sat, 30 Mar 2013 14:20:30 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Sat, 30 Mar 2013 14:15:00 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, March 29, 2013 11:17:28 PM UTC-4, Sylvia Else wrote:


You can look at it this way: All the input current flows through the

primary, and all the output current flows through both the primary and

the secondary. But the output current is in antiphase with the input

current, so most of the current in the primary is cancelled. The primary

has to handle only the difference between the input and output current.
Sylvia.

Huh? In boost mode , the transformer high side is the primary, and the low
voltage side is secondary . In buck mode, the transformer low voltage side
is the primary, the high voltage side is the secondary. In each case,
transformer high voltage side current is 1/10 transformer load voltage
side current. There's no looking at it this or that way, there's only
comprehension of what a transformer is.

Now, now, Freddy! To fit in here you need to learn to treat the
ignorant in a politically correct manner >:-}

Otherwise it'll be your turn to be attacked and told to change your
diaper ;-)

...Jim Thompson

Yep. Power is power, and if your secondary side load is pulling a
certain amount of power, you can bet the primary side is consuming
exactly that much, plus a bit more, in order to provide it.


Goddamned unformatted web based access retards should all get a clue
about line length in Usenet too.

 

On Friday, March 29, 2013 11:17:28 PM UTC-4, Sylvia Else wrote:

You can look at it this way: All the input current flows through the

primary, and all the output current flows through both the primary and

the secondary. But the output current is in antiphase with the input

current, so most of the current in the primary is cancelled. The primary

has to handle only the difference between the input and output current.
Sylvia.

Huh? In boost mode , the transformer high side is the primary, and the low voltage side is secondary . In buck mode, the transformer low voltage side is the primary, the high voltage side is the secondary. In each case, transformer high voltage side current is 1/10 transformer load voltage side current. There's no looking at it this or that way, there's only comprehension of what a transformer is.

 

[Sylvia Else]

On 31/03/2013 8:15 AM, bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, March 29, 2013 11:17:28 PM UTC-4, Sylvia Else wrote:


You can look at it this way: All the input current flows through
the

primary, and all the output current flows through both the primary
and

the secondary. But the output current is in antiphase with the
input

current, so most of the current in the primary is cancelled. The
primary

has to handle only the difference between the input and output
current. Sylvia.

Huh? In boost mode , the transformer high side is the primary, and
the low voltage side is secondary . In buck mode, the transformer low
voltage side is the primary, the high voltage side is the secondary.
In each case, transformer high voltage side current is 1/10
transformer load voltage side current. There's no looking at it this
or that way, there's only comprehension of what a transformer is.

Of course there are ways of looking at it. It's a device that operates
under the laws of physics, in the analysis and understanding of which
one can take any perspective that is physically valid, including such
things as superposition.

You appear to have absorbed the knowledge about how the voltages and
currents on the various windings are related, but not why they are
related that way, which depends on how currents produce fields, and how
changing fields produce emfs.

There are various takes on exactly what the OP was concerned about. My
take was that he was concerned about how connecting a conventional
transformed in an auto-transormer configuration can manage to increase
its power rating.

Sylvia.

 

[Sylvia Else]

On 31/03/2013 2:09 PM, bloggs.fredbloggs.fred@gmail.com wrote:

On Saturday, March 30, 2013 9:50:17 PM UTC-4, Sylvia Else wrote:

There are various takes on exactly what the OP was concerned about.
My

take was that he was concerned about how connecting a conventional

transformed in an auto-transormer configuration can manage to
increase

its power rating.


The answer is it doesn't increase the power rating of the
transformer. Analysis is what tells you the required transformer
power handling capability in the buck/boost configurations a lot more
than any fundamental physics. Maybe take it up a notch and declare a
N:1 stepdown xfrmr can be used in buck/boost circuits with loading up
to Nx KVA rating of the transformer.

How finely do you want to split that particular hair?

Sylvia.

 

On Saturday, March 30, 2013 9:50:17 PM UTC-4, Sylvia Else wrote:

There are various takes on exactly what the OP was concerned about. My

take was that he was concerned about how connecting a conventional

transformed in an auto-transormer configuration can manage to increase

its power rating.

The answer is it doesn't increase the power rating of the transformer. Analysis is what tells you the required transformer power handling capability in the buck/boost configurations a lot more than any fundamental physics. Maybe take it up a notch and declare a N:1 stepdown xfrmr can be used in buck/boost circuits with loading up to Nx KVA rating of the transformer.

 

[Jasen Betts]

On 2013-03-31, bloggs.fredbloggs.fred@gmail.com <bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, March 30, 2013 9:50:17 PM UTC-4, Sylvia Else wrote:

There are various takes on exactly what the OP was concerned about. My

take was that he was concerned about how connecting a conventional

transformed in an auto-transormer configuration can manage to increase

its power rating.


The answer is it doesn't increase the power rating of the
transformer. Analysis is what tells you the required transformer power
handling capability in the buck/boost configurations a lot more than
any fundamental physics. Maybe take it up a notch and declare a N:1
stepdown xfrmr can be used in buck/boost circuits with loading up to
Nx KVA rating of the transformer.

A 1kVA 1:1 transformer can be used as a 2kVA stepdown
auto-transformer.

I think the formul is actually a XkVA N:1 transformer has a (N+1)x kVA
rating as an autotransformer.

The Nx rating you give above seems to ignore the current in the
common leg.



--
⚂⚃ 100% natural

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

On Saturday, March 30, 2013 11:15:31 PM UTC-4, Sylvia Else wrote:

How finely do you want to split that particular hair?

Using obvious notation:

Actually, KVAXfmr= VLine/N x ILoad and KVALoad= Vline( 1+ 1/N)x ILoad so that Iload=KVALoad/[Vline(1+1/N)], making KVAXfmr=VLine/N x KVALoad/[VLine(1+1/N)]= KVALoad/(N+1) so you can use it with loads up to (N+1)x KVAXfmr , for boost. For buck the factor is VLine(1-1/N), so it can be used up to loads of (N-1)xKVAXfmr. Which makes sense because for the same KVA load, the current is greater for buck, but the transformer voltages always run at line.

 

[Phil Allison]

"Jasen Betts"

A 1kVA 1:1 transformer can be used as a 2kVA stepdown
auto-transformer.

** Only true if used in a system with DOUBLE the supply voltage the tranny
is rated for.

I think the formul is actually a XkVA N:1 transformer has a (N+1)x kVA
rating as an autotransformer.

** Simply a result of how the parameters are defined - not physics.

For one thing - the "power rating" of a tranny is proportional to the
applied primary voltage.

For example: raising the supply frequency allows more voltage to be applied
( before core saturation ) so up goes the VA rating too. A 50Hz tranny run
at 400Hz has 8 times the previous VA capacity - long as the insulation can
stand it.

Auto-transformers can be given very large VA ratings for their size - but
it is a nonsense as the tranny is suppling only a small part of the output.

The AC supply delivers the rest - directly to the load.


.... Phil

 

[John Larkin]

On 31 Mar 2013 05:27:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2013-03-31, bloggs.fredbloggs.fred@gmail.com <bloggs.fredbloggs.fred@gmail.com> wrote:
On Saturday, March 30, 2013 9:50:17 PM UTC-4, Sylvia Else wrote:

There are various takes on exactly what the OP was concerned about. My

take was that he was concerned about how connecting a conventional

transformed in an auto-transormer configuration can manage to increase

its power rating.


The answer is it doesn't increase the power rating of the
transformer. Analysis is what tells you the required transformer power
handling capability in the buck/boost configurations a lot more than
any fundamental physics. Maybe take it up a notch and declare a N:1
stepdown xfrmr can be used in buck/boost circuits with loading up to
Nx KVA rating of the transformer.

A 1kVA 1:1 transformer can be used as a 2kVA stepdown
auto-transformer.

Schematic?


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Jamie]

John Larkin wrote:

On 31 Mar 2013 05:27:30 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:


On 2013-03-31, bloggs.fredbloggs.fred@gmail.com <bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, March 30, 2013 9:50:17 PM UTC-4, Sylvia Else wrote:


There are various takes on exactly what the OP was concerned about. My

take was that he was concerned about how connecting a conventional

transformed in an auto-transormer configuration can manage to increase

its power rating.


The answer is it doesn't increase the power rating of the
transformer. Analysis is what tells you the required transformer power
handling capability in the buck/boost configurations a lot more than
any fundamental physics. Maybe take it up a notch and declare a N:1
stepdown xfrmr can be used in buck/boost circuits with loading up to
Nx KVA rating of the transformer.

A 1kVA 1:1 transformer can be used as a 2kVA stepdown
auto-transformer.


Schematic?


Yeah, Me too... I want to see that. That would be a new trick for me

to add to my bag..

Jamie

 

[John Larkin]

On Sun, 31 Mar 2013 08:10:16 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com
wrote:

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:


Schematic?


A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

Right, it works if you put the windings in series to make an autotransformer,
2:1 voltage ratio, but that's not a 1:1 buck, to play with words.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:

Schematic?

A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

 

[DecadentLinuxUserNumeroUn]

On Sun, 31 Mar 2013 10:08:21 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 08:10:16 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com
wrote:

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:


Schematic?


A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

Right, it works if you put the windings in series

"Series complimentary".

to make an autotransformer,
2:1 voltage ratio, but that's not a 1:1 buck, to play with words.

There is a proper glossary or terms for this, but few have landed on
target in all respects as yet.

 

[John Larkin]

On Sun, 31 Mar 2013 10:18:48 -0700, DecadentLinuxUserNumeroUno
<DLU1@DecadentLinuxUser.org> wrote:

On Sun, 31 Mar 2013 10:08:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 08:10:16 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com
wrote:

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:


Schematic?


A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

Right, it works if you put the windings in series

"Series complimentary".

to make an autotransformer,
2:1 voltage ratio, but that's not a 1:1 buck, to play with words.

There is a proper glossary or terms for this, but few have landed on
target in all respects as yet.

Transformers do what they do, and don't care much about words. Many transformers
don't even speak English.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[DecadentLinuxUserNumeroUn]

On Sun, 31 Mar 2013 10:21:55 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 10:18:48 -0700, DecadentLinuxUserNumeroUno
DLU1@DecadentLinuxUser.org> wrote:

On Sun, 31 Mar 2013 10:08:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 08:10:16 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com
wrote:

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:


Schematic?


A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

Right, it works if you put the windings in series

"Series complimentary".

to make an autotransformer,
2:1 voltage ratio, but that's not a 1:1 buck, to play with words.

There is a proper glossary or terms for this, but few have landed on
target in all respects as yet.

Transformers do what they do, and don't care much about words. Many transformers
don't even speak English.

Yeah? Try wiring it "in series' with the wrong starting lead first.

There are discreet series inductors, and there are series inductors
tied together within the same magnetic field.

They DO care about *those* words, turkey.

 

[John Larkin]

On Sun, 31 Mar 2013 10:39:02 -0700, DecadentLinuxUserNumeroUno
<DLU1@DecadentLinuxUser.org> wrote:

On Sun, 31 Mar 2013 10:21:55 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 10:18:48 -0700, DecadentLinuxUserNumeroUno
DLU1@DecadentLinuxUser.org> wrote:

On Sun, 31 Mar 2013 10:08:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 08:10:16 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com
wrote:

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:


Schematic?


A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

Right, it works if you put the windings in series

"Series complimentary".

to make an autotransformer,
2:1 voltage ratio, but that's not a 1:1 buck, to play with words.

There is a proper glossary or terms for this, but few have landed on
target in all respects as yet.

Transformers do what they do, and don't care much about words. Many transformers
don't even speak English.


Yeah? Try wiring it "in series' with the wrong starting lead first.

That can be done, depending on what you mean by "wrong."

Schematics, with notes and polarity dots, are a better way to convey things like
this.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[DecadentLinuxUserNumeroUn]

On Sun, 31 Mar 2013 10:58:15 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 10:39:02 -0700, DecadentLinuxUserNumeroUno
DLU1@DecadentLinuxUser.org> wrote:

On Sun, 31 Mar 2013 10:21:55 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 10:18:48 -0700, DecadentLinuxUserNumeroUno
DLU1@DecadentLinuxUser.org> wrote:

On Sun, 31 Mar 2013 10:08:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Sun, 31 Mar 2013 08:10:16 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com
wrote:

On Sunday, March 31, 2013 10:59:13 AM UTC-4, John Larkin wrote:


Schematic?


A 1:1 buck delivers 0 KVA to the load He must be talking about using the center tap of secondary for 2:1.

Right, it works if you put the windings in series

"Series complimentary".

to make an autotransformer,
2:1 voltage ratio, but that's not a 1:1 buck, to play with words.

There is a proper glossary or terms for this, but few have landed on
target in all respects as yet.

Transformers do what they do, and don't care much about words. Many transformers
don't even speak English.


Yeah? Try wiring it "in series' with the wrong starting lead first.

That can be done, depending on what you mean by "wrong."

Schematics, with notes and polarity dots, are a better way to convey things like
this.

In transformer speak:

"series complimentary" for "auto-transformer boost configuration".

What your opinion of being "better" hardly has any meaning when an
experienced electrician is in the field and needs to have such a thing
"conveyed" over an audible phone.

"These days" such a schematic would be easily available online. and
is.

And you don't need the notes if the winding start indicators (dots) are
there.

And they are also ALWAYS supposed to appear on the physical device as
well.