Hitecastro USB EQ Direct Interface problem

[Gina]

Thanks for your ideas

[sloz1664]

Gina I had issues with the FTDI cables on my EQ6 mount. I finally bit the bullet and went bluetooth via eqmod diy setup. 

Never had a com problem since.

Steve

[Starlight 1]

Gina, is this on your EQ8 mount ? you did get some water in it not so long ago may be take the sides off and have a look at the plugs on the board.

[lensman57]

I have been running it off a 13.8v 7A analogue PSU from Maplin.  A while back when I checked the voltage at the mount it was 13.2v.

Hi Gina,

I am sorry to hear of all these problems you have been having. I do have one of these Maplin 13.8V supplies, it is the same as yours ( the one in the black metal box ). I bought it to power the HEQ5 from my garage last year. I had problems running the mount with this power supply from the beginning as the mount would power up, slew to the alignment star and inexplicably loose alignment and reset itself after a few minutes. It happened time after time so in the end and to protect the mount I went back to the standard power supply and the mount started working properly. The connecting wire was one of those pricy stuff from FLO. It maybe totally unrelated to your problem but it is worth checking it out. The other issue maybe the power  receptor plug, it may just have a dry solder or a malfunctioning pin. Hope that you get better and sort the problem out.

Regards,

A.G

[Gina]

Gina I had issues with the FTDI cables on my EQ6 mount. I finally bit the bullet and went bluetooth via eqmod diy setup. 

Never had a com problem since.

Steve

That's interesting Steve - thank you

[Gina]

Gina, is this on your EQ8 mount ? you did get some water in it not so long ago may be take the sides off and have a look at the plugs on the board.

Yes it is the EQ8.  I'll check that - thanks

[Gina]

Hi Gina,

I am sorry to hear of all these problems you have been having. I do have one of these Maplin 13.8V supplies, it is the same as yours ( the one in the black metal box ). I bought it to power the HEQ5 from my garage last year. I had problems running the mount with this power supply from the beginning as the mount would power up, slew to the alignment star and inexplicably loose alignment and reset itself after a few minutes. It happened time after time so in the end and to protect the mount I went back to the standard power supply and the mount started working properly. The connecting wire was one of those pricy stuff from FLO. It maybe totally unrelated to your problem but it is worth checking it out. The other issue maybe the power  receptor plug, it may just have a dry solder or a malfunctioning pin. Hope that you get better and sort the problem out.

Regards,

A.G

Thank you   That's very interesting.  When I get the chance I'll check with the mount backed up and stabilised with a battery.  The mount's power light shows no sign of a power problem but that's no guarantee.

[Physopto]

Hi Gina,

 From all the bits that I have read so far, I really suggest that you go with a previous suggestion that you try it with the original Synscan hand controller. This will eliminate a faulty lead, If it does not work. If it does it will be the eqmod lead.

If it does not work then the mount is either faulty, or it's a power lead/plug supply problem, although this is unlikely as you say there is no flashing power led. This is supposing that the hand controller is OK. If you cannot find the hand controller possibly try to borrow one. If the hand controller lights up and goes through it's setup routine without problems,  but the mount still refuses to move then it is most likely a mount problem, board fault.

 I wish I could help but up in the North East.

Regards,

 Derek

[gajjer]

Hi Gina

Just to throw in my three penny worth about power supplies.

I run my NEQ6 from a 12Ah sealed lead acid battery that is charged from a small 2Amp charger.

A lot of power supplies these days are switching mode types. The stepper motors, as you know, are also run in switching mode. The combination of a switching supply and a switching load can be problematic.

The lead acid battery provides a reservoir like a big smoothing capacitor. This is important when it comes to a load that is taking current gulps. Sure the average current may be say 1A but the peaks can be much larger.

As you say, the LED power light may be on but the eye will not see short power interupts.

Personally, I would never feel comfortable running a mount on a power supply without a battery in parallel. But I am sure there is someone out there that has, with no problem what so ever.

good luck in cracking your problem. I know you will!

cheers

gaj

[Physopto]

Hi Gina,

 This is just a bit of info I came across a few weeks ago but forgot about. I hope it is of some interest to you and everyone who owns an EQ8.

http://www.dangl.at/ausruest/eq8/eq8_e3.htm

It describes different firmware revisions and the changes to the EQ8 power requirements.

Derek

[Gina]

Connected a car battery into the power supply to the mount at the pier end and the mount behaved pretty well   There was still a small error in parking position in one case but another was as near to perfect as I could tell.  I saved the park position to EQMOD ASCOM after setting it for each park position.  The mount showed no sign of failing with numerous movements, both slewing and parking.  So this seems to be this problem solved.  I can blame the Maplin PSU   I will make up a permanent arrangement later with fuses etc.

I now have another problem to chase up - the camera power feed has failed.  I dfidn't want to stay out too long today as I still have the virus and cough and I decided to leave fault finding for another day.  It's just a matter of checking with a DMM but I'd had enough for today.

[Tinker1947]

I think a bit of extra smoothing to the power supply might help.........

[Physopto]

Connected a car battery into the power supply to the mount at the pier end and the mount behaved pretty well   There was still a small error in parking position in one case but another was as near to perfect as I could tell.  I saved the park position to EQMOD ASCOM after setting it for each park position.  The mount showed no sign of failing with numerous movements, both slewing and parking.  So this seems to be this problem solved.  I can blame the Maplin PSU   I will make up a permanent arrangement later with fuses etc.

I now have another problem to chase up - the camera power feed has failed.  I dfidn't want to stay out too long today as I still have the virus and cough and I decided to leave fault finding for another day.  It's just a matter of checking with a DMM but I'd had enough for today.

Hi Gina,

Glad that you are getting somewhere.

I have had several problems with power supplies. Even using a battery as a float. It is very frustrating. One of the things that has come to light for me, is that if too many items are run from the same supply they can affect each other. Sudden load coming on can reduce the voltage at the equipment if the power line from the supply is too long. Even when using relatively large cable CSA.  A large current draw, say to the dew heaters will cause a drop in seen voltage at say the camera.  My QSI has been suffering from this. So now I am setting up two independent supplies. One for the CCD and A.O. unit and mount the other for the dew heaters. 

 I checked up with the manufacturers instructions and the QSI works between 11 and 14 volts. The EQ8 mount between 11 to 16 volts . The dew heater controller between 11.6 and 13.7. Kendrick do not state the upper limit in their literature. The QSI alarms and can shut down above 14 volts. This requires a full reboot of the camera.

Wouldn't it be sensible if all these manufacturers could get together and agree a voltage range for all so called 12 volt equipment!!!

Using a battery charger  fitted permanently in circuit can cause problems as the charging voltage raises to 14.4/14.6 volts. This is enough to cause permanent damage to some equipment.

If the battery voltage falls below 11.6 or 11 volts dependant upon equipment can also do the same.

 My way of combatting this is to fit 12 DC  volt  power bricks that output 12.2 volts DC and up to 5 amps at any input between 12 - 30 volts from the supply and battery. If the input voltage goes out of this range the supply shuts down. The ones I have are advertised at between 11 and 30 volts, but for some reason it is printed on the cases at 11-30 volts.

These voltage supplies are originally designed for TV's used in caravan/motorhomes as these devices  (12 volt) are not supposed to be run on anything over 12.6 volts.

I'm just hoping it all works, as I am still rewiring it all. Time will tell.

Regards,

 Derek

[Gina]

I've read in several articles that a 13.8v PSU makes a good continuous charger for a nominal 12v lead acid battery - particularly sealed ones since at that voltage no gassing is produced.  When the battery is charged the current drops to zero.  If you connect a partly discharged battery the current is limited by the battery internal resistance and also by that of the connecting wires.

13.8v seems to be well in the voltage range of all astro equipment I have come across that are described as 12v.

[Paul M]

I've read in several articles that a 13.8v PSU makes a good continuous charger for a nominal 12v lead acid battery - particularly sealed ones since at that voltage no gassing is produced.  When the battery is charged the current drops to zero.  If you connect a partly discharged battery the current is limited by the battery internal resistance and also by that of the connecting wires.

13.8v seems to be well in the voltage range of all astro equipment I have come across that are described as 12v.

I always understood that the very origin of 13.8v power supplies is that it is the optimal charging voltage for lead acid batteries, I.E. car batteries.

That's why car alternators are regulated at 13.8v.

Because of that, lots of portable equipment is rated for 13.8v too as a healthy car battery will rise to near that whilst the engine is running.

13.8v became an "industry standard" for a lot of portable equipment. We just call it 12v, but if there is a chance it will be plugged into a car accessory socket then it needs to be good for the full alternator output, if not optimised for it.

Why do I get the feeling you already know all this Gina?

[Gina]

Some of it but not all of it - thank you for the confirmation and extra info

[Physopto]

I always understood that the very origin of 13.8v power supplies is that it is the optimal charging voltage for lead acid batteries, I.E. car batteries.

That's why car alternators are regulated at 13.8v.

Because of that, lots of portable equipment is rated for 13.8v too as a healthy car battery will rise to near that whilst the engine is running.

13.8v became an "industry standard" for a lot of portable equipment. We just call it 12v, but if there is a chance it will be plugged into a car accessory socket then it needs to be good for the full alternator output, if not optimised for it.

Why do I get the feeling you already know all this Gina?

Hi Paul,

Sorry but this is incorrect. All car alternators once on load will rise to a 14.4 volts charging voltage. On first starting a car the alternator is not on load. It takes a few seconds to switch in, usually a blip on the throttle will bring it on load. A so called standard 12 volt lead acid battery should be charged up to 14.4 volts for it to be fully charged. A 12 volt battery consists of 6 cells at 2.4 volts each when charged. When fully charged, the charging voltage can be reduced to a maintenance charge of about 13.6 volts. This is to ensure that the battery is no longer outgassing and not being overcharged. A battery left on that full charge voltage will be damaged if left too long.

Caravan battery chargers are normally set at 13.6 volts so that the battery does not produce hydrogen gas. It would be unsafe for them to produce it especially in windless conditions near the caravan heaters etc.,( risk of explosion).  A battery that is under charged to 13.6 volts all the time will become damaged over a short period and eventually fail at an earlier time. This is put up with in the caravan industry  for safety reasons. I cannot remember the exact figures but a battery charged at 13.6 volts will be reduced to about 80% of a full charge.

Smart chargers that are used these days will check the battery voltage first to test the battery then will start charging at full current (called bulk charge). As the  battery voltage rises they will reduce the charge current slowly until the full battery voltage of 14.4 volts is reached. At that point they will usually reduce the charge voltage to a maintenance  13.6 volts. Under load if the voltage falls to below the required set voltage the charger again starts the bulk charge process and so on. These smart chargers can be left on continuously. Here in lies the problem for us out in the field. If we leave the smart charger charging the battery and the voltage falls below its set point it will start the bulk charge again and the voltage will rise possibly above our equipment Safe level. Please see the CTEK  website for more information on smart chargers.

A fully charged lead acid battery is 14.4 volts under charging conditions. Once the charger is out of circuit , e.g., disconnected from the battery, the battery voltage will slowly fall.  This will reduce to 12.8 volts, roughly over a 24 hour period. At 12.8 volts it is still fully charged, but the so called "surface charge" has dissipated. When at 12.4 volts it is only half charged. At 10.6 volts approximately it is fully discharged. There are one or two exceptions because of different manufacturing methods but the voltages vary by only a small amount.

 LiFePo4  batteries are a totally different kettle of fish! These batteries require a specialized charger and over temperature monitoring. Their voltages, over the battery discharge cycle vary very little until almost fully discharged, when the voltage suddenly falls sharply.

Gina is correct in that the 13.6 volts is an ideal voltage to leave on the lead acid battery, but only if fully charged in the beginning. This is, if you want to extend the battery to as long a life as possible.

I hope this helps.

Batteries are too  expensive to wreck needlessly.

Regards,

Derek

[Paul M]

Hi Paul,

Sorry but this is incorrect. All car alternators once on load will rise to a 14.4 volts charging voltage. On first starting a car the alternator is not on load. It takes a few seconds to switch in, usually a blip on the throttle will bring it on load. A so called standard 12 volt lead acid battery should be charged up to 14.4 volts for it to be fully charged. A 12 volt battery consists of 6 cells at 2.4 volts each when charged. When fully charged, the charging voltage can be reduced to a maintenance charge of about 13.6 volts. This is to ensure that the battery is no longer outgassing and not being overcharged. A battery left on that full charge voltage will be damaged if left too long.

Caravan battery chargers are normally set at 13.6 volts so that the battery does not produce hydrogen gas. It would be unsafe for them to produce it especially in windless conditions near the caravan heaters etc.,( risk of explosion).  A battery that is under charged to 13.6 volts all the time will become damaged over a short period and eventually fail at an earlier time. This is put up with in the caravan industry  for safety reasons. I cannot remember the exact figures but a battery charged at 13.6 volts will be reduced to about 80% of a full charge.

Smart chargers that are used these days will check the battery voltage first to test the battery then will start charging at full current (called bulk charge). As the  battery voltage rises they will reduce the charge current slowly until the full battery voltage of 14.4 volts is reached. At that point they will usually reduce the charge voltage to a maintenance  13.6 volts. Under load if the voltage falls to below the required set voltage the charger again starts the bulk charge process and so on. These smart chargers can be left on continuously. Here in lies the problem for us out in the field. If we leave the smart charger charging the battery and the voltage falls below its set point it will start the bulk charge again and the voltage will rise possibly above our equipment Safe level. Please see the CTEK  website for more information on smart chargers.

A fully charged lead acid battery is 14.4 volts under charging conditions. Once the charger is out of circuit , e.g., disconnected from the battery, the battery voltage will slowly fall.  This will reduce to 12.8 volts, roughly over a 24 hour period. At 12.8 volts it is still fully charged, but the so called "surface charge" has dissipated. When at 12.4 volts it is only half charged. At 10.6 volts approximately it is fully discharged. There are one or two exceptions because of different manufacturing methods but the voltages vary by only a small amount.

 LiFePo4  batteries are a totally different kettle of fish! These batteries require a specialized charger and over temperature monitoring. Their voltages, over the battery discharge cycle vary very little until almost fully discharged, when the voltage suddenly falls sharply.

Gina is correct in that the 13.6 volts is an ideal voltage to leave on the lead acid battery, but only if fully charged in the beginning. This is, if you want to extend the battery to as long a life as possible.

I hope this helps.

Batteries are too  expensive to wreck needlessly.

Regards,

Derek

Hi, thanks for the update!

At least my Googling just now would seem to agree with the historical origin of the 13.8 supply.

I'll be honest and say I've never measured a car battery at much more than 14v while under normal charge. But I rarely (read "never") tinker these days.

It would appear that while 13.8 is an acceptable output for an alternator it's on the lower end of the scale by modern standards. 

Perhaps the biggest downside to using a 13,8 bench PSU is finding one that's got the guts to charge a big battery that's fully discharged. Well, it probably won't happen at any reasonable cost.

I built a constant current charger to charge the big old car battery I used to use for out door stuff. Just have to watch the output voltage as the battery charges. That'll be where the intelligent chargers come in!

[Physopto]

Hi, thanks for the update!

At least my Googling just now would seem to agree with the historical origin of the 13.8 supply.

I'll be honest and say I've never measured a car battery at much more than 14v while under normal charge. But I rarely (read "never") tinker these days.

It would appear that while 13.8 is an acceptable output for an alternator it's on the lower end of the scale by modern standards. 

Perhaps the biggest downside to using a 13,8 bench PSU is finding one that's got the guts to charge a big battery that's fully discharged. Well, it probably won't happen at any reasonable cost.

I built a constant current charger to charge the big old car battery I used to use for out door stuff. Just have to watch the output voltage as the battery charges. That'll be where the intelligent chargers come in!

Hi Paul,

Yes you are correct about 13.6/8 volts, it varies. But all car alternators will charge up to 14.4 volts it's an industry standard. If the battery is well discharged to begin with it takes time for the voltage to rise up to 14.4 volts. So if the battery is at 10.6 volts you may only see about 11 volts at the start of charge. It depends upon the charger output amperage rating. The alternators are matched to the car/lorry battery size at manufacture. At sea we used all types of batteries some alkaline and some lead acid, but in large banks. We had 24 volt 12 volt depending upon the usage. Alkaline were normally used for the emergency radio and radio shack. We had to check them all for electrolyte levels each week as part of our maintenance schedule. The only alternators there were for the emergency generators. All work on the same ideas though. 13.8 is a safe charge voltage mostly but will never extend the battery life to its maximum. A 100 Ah will then only hold about 75/80% of its charge. Worse still as it is a lead acid you will only expect to get about 50% of that in useful power from it before the voltage has fallen to a level where it will cause problems. i.e. below 12.4 or 12.0 volts. With any external wiring introducing a further voltage drop due to resistance. If you measure a voltage at the end of a 50 foot wire when not using any current, by a millimetre it will show whatever is at the battery terminals. But under say 5 amp load the voltage is greatly reduced, dependant on the cable CSA, and whether it consists of aluminium, copper conductors. So you may only see 11.0 volts or a lot lower if the current is higher.

Still worse is the effect of low temperatures, this reduces the battery capacity even more. So we are all in the you know what, when out in the dark cold perfect conditions we all want.

Life is just a sod at times!

I'm going with voltage regulated 12 volt t DC to 12 volt DC regulated convertors in an attempt to sort it out. I need a long cable run of about 20 feet, (40 foot round trip). I'm using 2.5mm csa cable and at 10 amps will loose just under 1 volt in total as I have doubled up some of the wire to reduce resistance even further. For my equipment to get above 12.6 volts that means about 14 volts at the battery. But when current consumption is low the seen voltage at the telescope and ccd could be nearly 13 volts. When under a normal charger it could be even higher. The DC/DC voltage supplies will regulate this to safe levels as these are at the scope end. Even if the battery voltage at the scope end  falls to 11 volts they will supply 12.2 volts at up to 5 amps to my equipment.

I just believe in being very careful. Some of these DC/DC convertors are expensive £40 each but I found a supplier that does them at about £14 each. I haven't tried it yet as am still wiring up the system. In theory should stop problems that I have experienced and several  lost imaging runs. It also stops/isolates transient spikes from propagating between mount, scope and ccd.

It is my attempt at sorting out these problems anyway. It may even save the EQMOD USB signal cables from getting goosed who knows.

Regards,

Derek