Home made positioner

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My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#1
So far I have been 'positioning' my dish with a 12volt battery and a signal meter. I'd like to change this for something connected to the parallel port of my PC. It's an ACME actuator I bought about 10 years ago, with 4 wires - two are for the motor, which have to be reversed depending on direction, and another two probably for the positioning pulses??? Can anyone point me to any circuits that can be used for this? I don't really want to take the actuator apart and I've long since lost the documentation, but I imagine they work the same way.

thanks for any help,
-biff.
 
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#2
Can I just ask why don't you just buy a V-box?
it cost around £60, has a remote, does not need your pc to be runing and most probably your reciever can control it.
Regards B
 

T_G

The Consumate Dreamer
Staff member
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6,641
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212
My Satellite Setup
1 GigaBlue Quad plus, 1 Dreambox 5620, MOTECK SG2100A DISEqC Motor, 120 cm noname offset dish, Humax 95 cm offset dish and a few UK digiboxes.
My Location
Somewhere where the Sauer is Kraut and the Wurst is Brat
#3
I don't know what receiver you got, but an sg1200 motor costs about 60 Euro new, and works with Diseqc. If you got a skystar PC card it works very well.
 

Orthoclipse

Regular Member
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My Satellite Setup
Various
#4
h**p://ventoso.org/luca/vdr/index.html
h**p://www.holman.cz/hg/index.htm
h**p://www.viara.cn/diseqc/
 
Messages
18
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0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#5
Borsalino said:
Can I just ask why don't you just buy a V-box?
it cost around £60, has a remote, does not need your pc to be runing and most probably your reciever can control it.
Regards B
I don't have £60 to spend on something I can make for a tenner! Also, is a V-box programmable from Python??? :-).
-biff.
 
Messages
18
Likes
0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#6
Orthoclipse said:
h**p://ventoso.org/luca/vdr/index.html
h**p://www.holman.cz/hg/index.htm
h**p://www.viara.cn/diseqc/
Brilliant... The first link is the best. I should have it working by the w/e, hopefully.
cheers,
-biff.
 

T_G

The Consumate Dreamer
Staff member
Messages
6,641
Likes
212
My Satellite Setup
1 GigaBlue Quad plus, 1 Dreambox 5620, MOTECK SG2100A DISEqC Motor, 120 cm noname offset dish, Humax 95 cm offset dish and a few UK digiboxes.
My Location
Somewhere where the Sauer is Kraut and the Wurst is Brat
#7
bifferos said:
I don't have £60 to spend on something I can make for a tenner! Also, is a V-box programmable from Python??? :-).
-biff.
First of all, I said 60 Euro. That is about 40 quid.
But if you can get a reliable working motor for a tenner, that's ok even though I think it will be more than that in the end. But let us know how you get on with this project, I would be very interested in seeing some pictures and details.
 

frund

Specialist Contributor
Messages
279
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0
My Satellite Setup
triax 1.1 tm 1500ci+ dm patch. Moteck 2100. Intel 4300 based pc . LG7500. 32" lcd
My Location
Wales. UK.
#8
With the advice from this site I got a 2100 for £40 inc del great. Eb** Well pleased. Had to go abroad for it.
 

mhku

Super Moderator
Staff member
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4,712
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My Satellite Setup
TM Nano ~ sg2100
My Location
Midlands
#9
That's where I got mine from...
 

steffo78

Regular Member
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71
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0
My Satellite Setup
28E 19E on 120cm Gibertini homemade sidemount with Gibertini feedhorn, Inverto C120. 5E 1W on 85cm triax. Digiality VC-CI 204 and Triax dvb-65s receivers. Matrix-cam not working. Swedish Canaldigital "local", Norwegian Viasat.
My Location
Sweden/Norway,Telemark
#10
Very nice thread:) When I get a pm for my dish maybe this is an option to consider. Although the digital parts is not my strong side.It is not often you can save money by building it yourself.
And I totally understand why, it is nice to use equipment that you have made.
Also when using 36volts and budget-system you only have the option with v-box or manual.
Biff! pictures would be nice when you get it working!!
 
Messages
18
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0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#11
T_G said:
First of all, I said 60 Euro. That is about 40 quid.
But if you can get a reliable working motor for a tenner, that's ok even though I think it will be more than that in the end. But let us know how you get on with this project, I would be very interested in seeing some pictures and details.
OK, I stand corrected, 40 quid then. However, since the rest of the system is also homebrew, I need to be able to programmatically control the dish position, and I'm not sure what the possibilities are with off-the-shelf systems (even if the cost sounds reasonable).

So far I've started on the first link, which is about a plug-in for VDR h**p://ventoso.org/luca/vdr/index.html. I looked at VDR but it seems it's not for me. I have a headless PC in the garage, so all my watching will be done over the ethernet. Currently I'm using dvbstream to send an RTP stream to mplayer on my laptop and that's working pretty well, unfortunately it's not particularly usable and it doesn't record, so I'll hack together some basic software to do that as well.

Some more details about the circuit (in case anyone is interested)
I already had a cheap dual-channel relay board off ebay, so I'll be using that for the driving part. The circuit is much the same as the one at ventoso.org, except it uses PNP transistors (Grrr... I hate PNP logic). Unfortunately it's also 6 volts, and I wasted a certain amount of time getting 6 volts from the PC power supply. Never mind.
I've wired up the pulse sensing circuit, and it seems to be reading the pulses from the actuator fine (putting 12 volts across the reed relay). I used a 40106BE (CMOS logic IC I had from >10 years ago) for the schmitt trigger, and an MOC3020 for the opto-isolator, which actually has triac output (overkill) but whatever. Otherwise, that circuit does seem to work. I'm surprised how slow the pulses are - I guess it doesn't have to be that accurate because wind blowing the dish introduces error anyhow. One thing I did add to the circuit was an LED to show the reed relay status, so I can clearly see when the dish is moving (the LED flashes with the pulses).

Next step will be to connect this pile of electronics to the parallel port and try to program it. The actuator draws about 2.5 amps, so I'm not sure right now whether I can get away with running off the PC supply or I'll have to have something else. Suspect I'll need some supply decoupling at the very least.

-biff

PS: I'll post a pic somewhere once I'm sure it works!
 

T_G

The Consumate Dreamer
Staff member
Messages
6,641
Likes
212
My Satellite Setup
1 GigaBlue Quad plus, 1 Dreambox 5620, MOTECK SG2100A DISEqC Motor, 120 cm noname offset dish, Humax 95 cm offset dish and a few UK digiboxes.
My Location
Somewhere where the Sauer is Kraut and the Wurst is Brat
#12
wow, very technical and interesting. Keep us informed how you get on, and we sure would like to see some pictures of all the parts!
 
Messages
18
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0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#13
Right-hand pic:

This is the whole thing. There's a board glued to the top of an ATX PSU (don't ask - from another project:D). The relay board (top-right) was bought as a kit off ebay. Bottom-left goes to the PC serial port, bottom right to the dish.


Left-hand pic:


This is the bit that does the business. I didn't really need the LED, but thought it might be useful to see the pulses from the actuator. The big fat resistor at the back is to stabilise the PC power supply (ATX PSUs don't like being run not connected to a PC!). The bits you can't do without are the two opto-isolators, two diodes (betwen the two optos) and three resistors.

You can make a very similar circuit to interface to the parallel port. I went for serial, because my PC has two serial ports and only one parallel (an extra chance in case I blew it up:-ohmy). One other reason is that serial ports have current-limiting resistors built in, so slightly more protection than a parallel port offers.


laters,

-biff.
 

Attachments

Llew

cerca trova...
Staff member
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My Satellite Setup
Triple Dragon, Dreambox 8000, Echostar AD3000ip, TBS6522,6925,6983 PCie cards.
Gibertini 1.25m motorised dish driven by the AD3000, with either Inverto BU Quad or Norsat / XMW Ka LNBs . SMW 1.05m + 3 other dishes. Speccy: Promax HD Ranger+
My Location
The Flatlands of East Anglia
#14
The big question - is it working OK? 12V enough to run the motor?

I'm assuming you have the software up and running.

(Best to just attach the thumbnails, saves us having to scroll right)

Llew
 
Messages
18
Likes
0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#15
Llew said:
The big question - is it working OK? 12V enough to run the motor?

I'm assuming you have the software up and running.

(Best to just attach the thumbnails, saves us having to scroll right)

Llew
Answers:
-Yes,
-yes,
-yes,
-(Sorry - my first post to a forum involving pictures)
 

Llew

cerca trova...
Staff member
Messages
14,466
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My Satellite Setup
Triple Dragon, Dreambox 8000, Echostar AD3000ip, TBS6522,6925,6983 PCie cards.
Gibertini 1.25m motorised dish driven by the AD3000, with either Inverto BU Quad or Norsat / XMW Ka LNBs . SMW 1.05m + 3 other dishes. Speccy: Promax HD Ranger+
My Location
The Flatlands of East Anglia
#16
A suggestion - Why not build a beefier power supply, a linear one would be simple to construct for your purpose:

1x toroidal xfmr 18x18V 80VA (Maplins £15)

1x Bridge rectifier

Er... that's about it. No smoothing electrolytic necessary - I remember a Pace positioner I had didn't have much else in the power supply, apart from another secondary winding for the control circuitry.

Llew
 
Messages
18
Likes
0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#17
Llew said:
A suggestion - Why not build a beefier power supply, a linear one would be simple to construct for your purpose:

1x toroidal xfmr 18x18V 80VA (Maplins £15)

1x Bridge rectifier

Er... that's about it. No smoothing electrolytic necessary - I remember a Pace positioner I had didn't have much else in the power supply, apart from another secondary winding for the control circuitry.

Llew
You've forgotten one important component - the box!! This is mains :-).

Interesting to know what it looks like inside a real postioner, but since it's working at 12v, and I don't mind the speed it moves at think I'll stick with what I've got.

Just done a search on Ebay and found an AT PSU with <1 min going out for 99p. Mine was for free from a dead PC, so even less!

I'm certainly interested to know what an actuator draws from a 36v supply. At 12volts, mine is drawing 2.5 amps. I've seen 12volt, 1 amp switching 'brick' supplies, I think that's the highest you can get off-the-shelf. You could also put three of them together to make 36 volts, thereby avoiding messing with mains, needing a proper box etc..., although it might be slightly more costly.

-biff.
 

Llew

cerca trova...
Staff member
Messages
14,466
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My Satellite Setup
Triple Dragon, Dreambox 8000, Echostar AD3000ip, TBS6522,6925,6983 PCie cards.
Gibertini 1.25m motorised dish driven by the AD3000, with either Inverto BU Quad or Norsat / XMW Ka LNBs . SMW 1.05m + 3 other dishes. Speccy: Promax HD Ranger+
My Location
The Flatlands of East Anglia
#18
LOL, I'm sure with your undoubted skills you wouldn't construct it on a breadboard :-doh! Just assumed you'd have something suitable to hand.

My actuator draws less than an amp in running, perhaps a little more at startup.
 
Messages
18
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0
My Satellite Setup
1.2 Metre Dish, Channel Master H-H mount, ACME Actuator, Skystar2, PIII-600MHz
My Location
UK
#19
Llew said:
LOL, I'm sure with your undoubted skills you wouldn't construct it on a breadboard :-doh! Just assumed you'd have something suitable to hand.

My actuator draws less than an amp in running, perhaps a little more at startup.
Hmm... Something suitable to hand that clamps the mains cable incase the box gets knocked on the floor, a grommet for the place the cable goes in, so it doesn't get bent out of shape, something to mount the toroid on inside the box, something to keep its leads from coming together, then the same again for the low voltage side, then maybe think about a fuse?

Take it from me - it's really not that simple, which is why a lot of modern equipment comes with wall-warts. They mass-produce the high voltage side to the relevant safety standards, then the device itself doesn't need such careful design WRT heat, isolation etc..

This is why an AT(X) PSU is so attractive. There's no way I could legally do business selling the positioner I've built, but at least there is some notion of safety, because I haven't messed with anything inside the box as shipped from the factory, and it has been subjected to inspection.

It's not that I won't touch mains - it's just that it's a *lot* of extra work if you want it to be properly safe.

-biff
 

T_G

The Consumate Dreamer
Staff member
Messages
6,641
Likes
212
My Satellite Setup
1 GigaBlue Quad plus, 1 Dreambox 5620, MOTECK SG2100A DISEqC Motor, 120 cm noname offset dish, Humax 95 cm offset dish and a few UK digiboxes.
My Location
Somewhere where the Sauer is Kraut and the Wurst is Brat
#20
Wow I cannot but marvel at your knowledge in these electrical matters...very interesting! Keep informing us how you get on!
 
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