Inverter issue


Suresh Mohan
 

Last weekend and today I ran into my mount stalling while slewing , my normal power source is a 12 v 5 amp source from 220 v ac . At dark site I use a deep cycle 165 ah battery - inverter and run my mount . Both last week and today my mount stalled , all other stuff worked . So I just removed the power source from inverter and via alligator pin ran the mount and it works fine . What s the issue between inverter and servo motor ?
Thanks
Suresh


Roland Christen
 

An inverter takes 12 volts DC and "inverts" it to 120 or 240 volts AC. An inverter cannot run a 12 volt powered mount unless it is also followed by a 120/240AC to 12 volt DC power supply. Inverting 12 volts DC to 120/240 and then back down to 12 volts DC is a convoluted way to power a mount. It is not going to be as rugged as simply using the 12 volt source to begin with.

I don't know why specifically your mount stalled, but chances are good that you did not have sufficient voltage at the controller power input. You may also have a poor connection on the 12 volt pin of the CP3. This can be remedied by taking a small bladed screw driver and gently spreading the power pin on the CP3 so that it makes good solid contact with the 12 volt plug on your power cord. See the app note on our website if you are unsure about the power pin.

Rolando



-----Original Message-----
From: Suresh Mohan <drsureshmohan@...>
To: main <main@ap-gto.groups.io>
Sent: Sat, Feb 1, 2020 10:28 am
Subject: [ap-gto] Inverter issue

Last weekend and today I ran into my mount stalling while slewing , my normal power source is a 12 v 5 amp source from 220 v ac . At dark site I use a deep cycle 165 ah battery - inverter and run my mount . Both last week and today my mount stalled , all other stuff worked . So I just removed the power source from inverter and via alligator pin ran the mount and it works fine . What s the issue between inverter and servo motor ?
Thanks
Suresh



Steven Panish
 

Suresh-  If your site is cold the mount will prefer a higher voltage, check the manual for your mount/controller.  Buy a cheap ($5) buck/boost regulator on Ebay, feed the DC battery into it, and set the regulator output voltage for what is recommended.  I use 16.5v for my 1200.  

As Roland said, the inverter is only for DC to AC conversion, so all you would use it for is running a battery charger meant to run off household line current.  Which is what I presume you are doing but the description wasn't clear to me.

Steve


Suresh Mohan
 

Roland , 
  On the field my 165 ah 12 v to power inverter and then 220 v correct to my mounts 12 v converter has an issue ( I don’t know what’s a sine wave inverter ( that’s what it says ) and that is not able to run my mount . I guess the inverter has some issue to run my servo motor of mount . Direct from battery or 12 v 5 amp from ac at home has no issue
Suresh


On 01-Feb-2020, at 10:11 PM, uncarollo2 <chris1011@...> via Groups.Io <chris1011@...> wrote:


An inverter takes 12 volts DC and "inverts" it to 120 or 240 volts AC. An inverter cannot run a 12 volt powered mount unless it is also followed by a 120/240AC to 12 volt DC power supply. Inverting 12 volts DC to 120/240 and then back down to 12 volts DC is a convoluted way to power a mount. It is not going to be as rugged as simply using the 12 volt source to begin with.

I don't know why specifically your mount stalled, but chances are good that you did not have sufficient voltage at the controller power input. You may also have a poor connection on the 12 volt pin of the CP3. This can be remedied by taking a small bladed screw driver and gently spreading the power pin on the CP3 so that it makes good solid contact with the 12 volt plug on your power cord. See the app note on our website if you are unsure about the power pin.

Rolando



-----Original Message-----
From: Suresh Mohan <drsureshmohan@...>
To: main <main@ap-gto.groups.io>
Sent: Sat, Feb 1, 2020 10:28 am
Subject: [ap-gto] Inverter issue

Last weekend and today I ran into my mount stalling while slewing , my normal power source is a 12 v 5 amp source from 220 v ac . At dark site I use a deep cycle 165 ah battery - inverter and run my mount . Both last week and today my mount stalled , all other stuff worked . So I just removed the power source from inverter and via alligator pin ran the mount and it works fine . What s the issue between inverter and servo motor ?
Thanks
Suresh



Suresh Mohan
 

Ha ,
    It’s 24 c !!! For you guys  this must feel hot at 75 f
Suresh 


On 01-Feb-2020, at 10:33 PM, Steven Panish <scpanish@...> wrote:


Suresh-  If your site is cold the mount will prefer a higher voltage, check the manual for your mount/controller.  Buy a cheap ($5) buck/boost regulator on Ebay, feed the DC battery into it, and set the regulator output voltage for what is recommended.  I use 16.5v for my 1200.  

As Roland said, the inverter is only for DC to AC conversion, so all you would use it for is running a battery charger meant to run off household line current.  Which is what I presume you are doing but the description wasn't clear to me.

Steve


Suresh Mohan
 

Steve in India due to frequent power outage we use so called inverters that source power from 12 v battery and convert to 220 v . When there is electricity it also charges the battery
Regards
Suresh


On 01-Feb-2020, at 10:33 PM, Steven Panish <scpanish@...> wrote:


Suresh-  If your site is cold the mount will prefer a higher voltage, check the manual for your mount/controller.  Buy a cheap ($5) buck/boost regulator on Ebay, feed the DC battery into it, and set the regulator output voltage for what is recommended.  I use 16.5v for my 1200.  

As Roland said, the inverter is only for DC to AC conversion, so all you would use it for is running a battery charger meant to run off household line current.  Which is what I presume you are doing but the description wasn't clear to me.

Steve


Steven Panish
 

That's for sure.  I'm up near Canada.  Temperatures are well below freezing on the average.  Your battery voltage will be fine as is.

Steve


Steven Panish
 

Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve


Ron Kramer
 

Wouldn't plugging the AC/DC adapter (power supply for the mount) into an inverter be DC and fine? Mine is pure sine wave version.


On Sat, Feb 1, 2020 at 1:22 PM Steven Panish <scpanish@...> wrote:
Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve




Mike Dodd
 

On 2/1/2020 1:26 PM, Ron Kramer wrote:
Wouldn't plugging the AC/DC adapter (power supply for the mount) into an
inverter be DC and fine? Mine is pure sine wave version.
Yes, I believe so. I think this thread has become clouded by references to "inverter" and "220V."

It seems clear to me that the OP is using a better to power a 220VAC inverter, into which he plugs a power supply that produces the 12V-15V needed for the mount.

--
Mike

Mike Dodd
Louisa County, Virginia USA
http://astronomy.mdodd.com


Steven Panish
 

Yes.  That is what the inverter is for, tto supply AC power from a DC battery.  But if you already have a battery supplying 12V DC, you don't need to use the inverter and an AC->DC power supply to drive a mount that wants 12V dc.  You can run the mount directly off the battery.  But to be safe, you can regulate the power out of the battery with a DC to DC regulator, and you should fuse this with the recommended fuse.  Using the inverter in the loop makes the whole thing very inefficient power wise.

STeve

On Sat, Feb 1, 2020 at 1:27 PM Ron Kramer <ronkramer1957@...> wrote:
Wouldn't plugging the AC/DC adapter (power supply for the mount) into an inverter be DC and fine? Mine is pure sine wave version.


On Sat, Feb 1, 2020 at 1:22 PM Steven Panish <scpanish@...> wrote:
Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve



--


Suresh Mohan
 

Dear friends ,
     In india we only have 220 volts instead of110 v in the us . At home I have a 220 v ac to 12 v dc adapter 5 amp that runs my mount fine . Out in the field I need aninverter  to give out 220 v to run my laptop , since I have the ac wall adapter for the mount  I ran that too - but my mount stalled ( only in the field via inverter to dc conversion ). I assumed that has something to do with powering a servo motor that works fine when fixed to a wall ac socket via dc converter )
Sorry if I had not been clear - it’s  4 am here
Regards and thanks my friends for responding 
Suresh


On 02-Feb-2020, at 12:03 AM, Steven Panish <scpanish@...> wrote:


Yes.  That is what the inverter is for, tto supply AC power from a DC battery.  But if you already have a battery supplying 12V DC, you don't need to use the inverter and an AC->DC power supply to drive a mount that wants 12V dc.  You can run the mount directly off the battery.  But to be safe, you can regulate the power out of the battery with a DC to DC regulator, and you should fuse this with the recommended fuse.  Using the inverter in the loop makes the whole thing very inefficient power wise.

STeve

On Sat, Feb 1, 2020 at 1:27 PM Ron Kramer <ronkramer1957@...> wrote:
Wouldn't plugging the AC/DC adapter (power supply for the mount) into an inverter be DC and fine? Mine is pure sine wave version.


On Sat, Feb 1, 2020 at 1:22 PM Steven Panish <scpanish@...> wrote:
Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve



--


Suresh Mohan
 

One last thing I’m gonna teat at dawn , I also carry a car inverter , I might want to try slewing the mount thro that just to make sure that it’s only only the field inverter that s giving a problem
Suresh 


On 02-Feb-2020, at 3:55 AM, Suresh Mohan via Groups.Io <drsureshmohan@...> wrote:

Dear friends ,
     In india we only have 220 volts instead of110 v in the us . At home I have a 220 v ac to 12 v dc adapter 5 amp that runs my mount fine . Out in the field I need aninverter  to give out 220 v to run my laptop , since I have the ac wall adapter for the mount  I ran that too - but my mount stalled ( only in the field via inverter to dc conversion ). I assumed that has something to do with powering a servo motor that works fine when fixed to a wall ac socket via dc converter )
Sorry if I had not been clear - it’s  4 am here
Regards and thanks my friends for responding 
Suresh


On 02-Feb-2020, at 12:03 AM, Steven Panish <scpanish@...> wrote:


Yes.  That is what the inverter is for, tto supply AC power from a DC battery.  But if you already have a battery supplying 12V DC, you don't need to use the inverter and an AC->DC power supply to drive a mount that wants 12V dc.  You can run the mount directly off the battery.  But to be safe, you can regulate the power out of the battery with a DC to DC regulator, and you should fuse this with the recommended fuse.  Using the inverter in the loop makes the whole thing very inefficient power wise.

STeve

On Sat, Feb 1, 2020 at 1:27 PM Ron Kramer <ronkramer1957@...> wrote:
Wouldn't plugging the AC/DC adapter (power supply for the mount) into an inverter be DC and fine? Mine is pure sine wave version.


On Sat, Feb 1, 2020 at 1:22 PM Steven Panish <scpanish@...> wrote:
Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve



--


Don Anderson
 

Hello Suresh
If your mount works fine with the 12V battery only, I suspect there is nothing wrong with the CP3 controller or the power cable connector where it attaches to the controller. One thing you should check is to see if your inverter is putting out enough current to supply all the devices connected to it. If you have a laptop, heaters mount and camera(s) connected. You may be short of capacity. What could be happening is as soon as you slew the mount, the extra current draw may drop the voltage at the controller below the allowable limit.

Don Anderson


On Saturday, February 1, 2020, 03:32:50 p.m. MST, Suresh Mohan <drsureshmohan@...> wrote:


One last thing I’m gonna teat at dawn , I also carry a car inverter , I might want to try slewing the mount thro that just to make sure that it’s only only the field inverter that s giving a problem
Suresh 


On 02-Feb-2020, at 3:55 AM, Suresh Mohan via Groups.Io <drsureshmohan@...> wrote:

 Dear friends ,
     In india we only have 220 volts instead of110 v in the us . At home I have a 220 v ac to 12 v dc adapter 5 amp that runs my mount fine . Out in the field I need aninverter  to give out 220 v to run my laptop , since I have the ac wall adapter for the mount  I ran that too - but my mount stalled ( only in the field via inverter to dc conversion ). I assumed that has something to do with powering a servo motor that works fine when fixed to a wall ac socket via dc converter )
Sorry if I had not been clear - it’s  4 am here
Regards and thanks my friends for responding 
Suresh


On 02-Feb-2020, at 12:03 AM, Steven Panish <scpanish@...> wrote:


Yes.  That is what the inverter is for, tto supply AC power from a DC battery.  But if you already have a battery supplying 12V DC, you don't need to use the inverter and an AC->DC power supply to drive a mount that wants 12V dc.  You can run the mount directly off the battery.  But to be safe, you can regulate the power out of the battery with a DC to DC regulator, and you should fuse this with the recommended fuse.  Using the inverter in the loop makes the whole thing very inefficient power wise.

STeve

On Sat, Feb 1, 2020 at 1:27 PM Ron Kramer <ronkramer1957@...> wrote:
Wouldn't plugging the AC/DC adapter (power supply for the mount) into an inverter be DC and fine? Mine is pure sine wave version.


On Sat, Feb 1, 2020 at 1:22 PM Steven Panish <scpanish@...> wrote:
Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve



--


Steven Panish
 

Don is correct, although typically if you pull too much current out of an inverter it will blow a fuse or breaker.  Try running the mount right off the battery if you can make up a cable.  Fusing that is a good safety precaution.  It is also possible the the AC to DC converter has a bad connection which is showing up in the field.

The car inverter is likely square wave output which may not work for the mount.  And BTW, if the main inverter is failing and putting out a poor waveform, some devices will work, and some will not.

STeve


Suresh Mohan
 

Ah , yes highly possible Don
Suresh


On 02-Feb-2020, at 5:41 AM, Don Anderson via Groups.Io <jockey_ca@...> wrote:


Hello Suresh
If your mount works fine with the 12V battery only, I suspect there is nothing wrong with the CP3 controller or the power cable connector where it attaches to the controller. One thing you should check is to see if your inverter is putting out enough current to supply all the devices connected to it. If you have a laptop, heaters mount and camera(s) connected. You may be short of capacity. What could be happening is as soon as you slew the mount, the extra current draw may drop the voltage at the controller below the allowable limit.

Don Anderson


On Saturday, February 1, 2020, 03:32:50 p.m. MST, Suresh Mohan <drsureshmohan@...> wrote:


One last thing I’m gonna teat at dawn , I also carry a car inverter , I might want to try slewing the mount thro that just to make sure that it’s only only the field inverter that s giving a problem
Suresh 


On 02-Feb-2020, at 3:55 AM, Suresh Mohan via Groups.Io <drsureshmohan@...> wrote:

 Dear friends ,
     In india we only have 220 volts instead of110 v in the us . At home I have a 220 v ac to 12 v dc adapter 5 amp that runs my mount fine . Out in the field I need aninverter  to give out 220 v to run my laptop , since I have the ac wall adapter for the mount  I ran that too - but my mount stalled ( only in the field via inverter to dc conversion ). I assumed that has something to do with powering a servo motor that works fine when fixed to a wall ac socket via dc converter )
Sorry if I had not been clear - it’s  4 am here
Regards and thanks my friends for responding 
Suresh


On 02-Feb-2020, at 12:03 AM, Steven Panish <scpanish@...> wrote:


Yes.  That is what the inverter is for, tto supply AC power from a DC battery.  But if you already have a battery supplying 12V DC, you don't need to use the inverter and an AC->DC power supply to drive a mount that wants 12V dc.  You can run the mount directly off the battery.  But to be safe, you can regulate the power out of the battery with a DC to DC regulator, and you should fuse this with the recommended fuse.  Using the inverter in the loop makes the whole thing very inefficient power wise.

STeve

On Sat, Feb 1, 2020 at 1:27 PM Ron Kramer <ronkramer1957@...> wrote:
Wouldn't plugging the AC/DC adapter (power supply for the mount) into an inverter be DC and fine? Mine is pure sine wave version.


On Sat, Feb 1, 2020 at 1:22 PM Steven Panish <scpanish@...> wrote:
Suresh - Do not run the mount off the inverter!!!  The mount needs DC.  The inverter puts out AC.  

Sine wave means the output of the inverter does a good job of digitally simulating analog AC power.  Some inverters put out square wave power, which is lousy but ok for some devices.

STeve



--


Roland Christen
 


The car inverter is likely square wave output which may not work for the mount.
The mount runs on DC and doesn't care what waveform the AC is, square wave or sine makes no difference because it doesn't appear on the DC side.

Rolando


-----Original Message-----
From: Steven Panish <scpanish@...>
To: main <main@ap-gto.groups.io>
Sent: Sat, Feb 1, 2020 6:41 pm
Subject: Re: [ap-gto] Inverter issue

Don is correct, although typically if you pull too much current out of an inverter it will blow a fuse or breaker.  Try running the mount right off the battery if you can make up a cable.  Fusing that is a good safety precaution.  It is also possible the the AC to DC converter has a bad connection which is showing up in the field.

The car inverter is likely square wave output which may not work for the mount.  And BTW, if the main inverter is failing and putting out a poor waveform, some devices will work, and some will not.

STeve


Christopher Erickson
 

Every power conversion has an efficiency loss that will be someplace between 5 and 30%. Average being about 15%. Two conversions (13.7VDC->120/240VAC->12VDC) will likely have twice as much loss, plus the electronic components used in the conversions may be temperature sensitive and malfunction in freezing temperatures. Especially if they were designed for indoor applications only.

You can get an estimate of how efficient a power converter is by how warm it gets when working. The warmer it gets, the less efficient it is. That heat is lost energy.

Usually best to try to minimize power conversions in the field. No sense using battery power to heat the outdoors. Lots of hot power conversions in an observatory would be bad too. Regardless if the observatory is on grid power (mains power) or not.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   


On Sun, Feb 2, 2020, 6:34 AM uncarollo2 <chris1011@...> via Groups.Io <chris1011=aol.com@groups.io> wrote:

The car inverter is likely square wave output which may not work for the mount.
The mount runs on DC and doesn't care what waveform the AC is, square wave or sine makes no difference because it doesn't appear on the DC side.

Rolando


-----Original Message-----
From: Steven Panish <scpanish@...>
To: main <main@ap-gto.groups.io>
Sent: Sat, Feb 1, 2020 6:41 pm
Subject: Re: [ap-gto] Inverter issue

Don is correct, although typically if you pull too much current out of an inverter it will blow a fuse or breaker.  Try running the mount right off the battery if you can make up a cable.  Fusing that is a good safety precaution.  It is also possible the the AC to DC converter has a bad connection which is showing up in the field.

The car inverter is likely square wave output which may not work for the mount.  And BTW, if the main inverter is failing and putting out a poor waveform, some devices will work, and some will not.

STeve