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Re: Pin Identification of Digital Drive hand controller


Feb 14 6:11 PM

 


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#53871 Feb 14 6:11 PM

Hi,

Would anyone happen to be able to identify the six pins of the hand controller port of the Digital Drive? Which pin is common/ground?

Best regards,

John



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#53872 Feb 14 6:26 PM

John,



The HC/CCD port is wired from left to right No Contact, Common, -X, -Y, +Y, +X



Don

----- Original Message -----

From: jnassr2010@...>

To: Losmandy_users@yahoogroups.com>

Sent: Friday, February 14, 2014 9:11 PM

Subject: [Losmandy_users] Pin Identification of Digital Drive hand controller





> Hi,

>

> Would anyone happen to be able to identify the six pins of the hand controller port of the Digital

> Drive? Which pin is common/ground?

>

> Best regards,

>

> John

>



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#53874 Feb 14 7:15 PM

Don,

Okidoki, thank you!

John

On Saturday, February 15, 2014 10:26 AM, Don Degidio djd521@...> wrote:

��John,



The HC/CCD port is wired from left to right No Contact, Common, -X, -Y, +Y, +X



Don

----- Original Message -----

From: jnassr2010@...>

To: Losmandy_users@yahoogroups.com>

Sent: Friday, February 14, 2014 9:11 PM

Subject: [Losmandy_users] Pin Identification of Digital Drive hand controller



> Hi,

>

> Would anyone happen to be able to identify the six pins of the hand controller port of the Digital

> Drive? Which pin is common/ground?

>

> Best regards,

>

> John

>



----------------------------

#53876 Feb 15 12:04 PM

Maybe a nit but��� ��Actually, pin 1 is the power (pulse width modulated) to drive the LED in the hand controller. Pushing theBrightness button on the Digital Drive changes the intensity�� of it along with all the other LEDs. ��For guiders it is indeed No Connection (NC). The numbering is looking into the female (to be pre-PC about it)connector, contacts on the bottom. ��Mark C.



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#53877 Feb 16 9:06 AM

One last nit: The common pin (#2) is NOT power ground. It is the common signalreturn for the other four pins (#3-#6) of the guider interface. This is why a fewcameras (not many) need relays or external optoisolators to work properly. Cameraswith internal relays or optos, that float the signal return do not have a problem, whilethose for which the camera designer rashly assumed that the signal return was powerground got into trouble. ��And, by the way, the other four pins have a 33% duty cycle, 168HZ, square wave onthem, not DC as I recently discovered with an oscilloscope! Apparently the (quite old design)processor timeshares the pins with other functions: There are about 34 I/Os on the processorand there are all those pesky LEDs to drive (including the VTC/backlash compensation status)on the panel. The square wave was confirmed by the engineers at Losmandy. I searched theweb and the file section and nobody seems to have commented on this before but then thesearch capabilities of the Yahoogroups is not the best. ��That is why, when you put a normal DC multi-meter across pin #2 and any of the guiderinputs you see a 1.65V (approximate) voltage: It is a 33% sample of 5V averaged. Other mountsshow a nice DC signal at their guider outputs, at least the two that I have access to check. ��The osilly-scope also shows a ground bounce in the pulse waveform, by the way, until aslight (1-10K ohms seems like enough) resistive load is put across #2 and each of the others.Relay contacts won���t care but depending on the characteristics of the conduction transistorin the opto you might or might not see a problem with the spikes driving the bounce.Depending on the optos selected by the camera/interface designer the on-resistance ofthe transistor can vary a lot. And the ground bounce is very different depending on the DCpower source feeding the mount. Batteries produce a reasonable waveform (but you canstill see the spikes), while some AC adapters (esp. linear supplies, even ones rated for6AMPS with nice big capacitors) seem to ring in response to the spikes. ��Nothing is every simple it seems. Between sessions of shoveling snow and other projects I havebeen preparing a note on this topic, in case anybody is interested. ��Mark Christensen



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