Remote Control for the Samsung SDC-435/SCB-2000
By Tom Hering
Discovery:
After I got my SDC-435 and started to play with it both inside and out at the telescope, I discovered rather quickly that it was lacking in a very important way…that is it was very difficult to adjust the On Screen Display (‘OSD’) without upsetting the telescope. Also, it was very hard to adjust by hand, feeling the push buttons while trying to watch the monitor, which more than likely is in an entirely different direction. This camera did a very nice job for a little bit of money, but it was no ‘M-Cam’ or ‘S-Cam’ because it did not have a remote control to adjust the camera with. A remote that would allow the user to tweak the frequent and touchy settings of the 435 without shaking the image all over the place and perhaps be up to 300 feet (maybe?) away from the telescope while doing so. I want to run my telescope and camera remotely from my little Dell Netbook computer located some distance from the observing site. A solution was needed!
Now I should tell you, that I am an experienced electronics technician. So I set to work disassembling my camera so as to evaluate the situation. I pulled the Infra-red filter while I was at it. (Why do we do that, anyway?) Removing the IR filter messes up the preset white balance setting of the camera so you will have to readjust the white balance manually. After I got the camera apart, I located the circuit card of interest; that being the ‘Back’ card assembly, the one on the back of the camera with the power connections and the BNC video out jack. I studied it for a while and decided all that was necessary was to use some small flexible multi conductor cable and solder the necessary number of wires (6) to the switch solder pads on the card assembly. This cable could then be connected to the hand control box I was going to build. The box would have 5 momentary switches to mimic the 5 switches on the camera and one wire extra for chassis ground. The camera switches simply make contact or ground the wires going to a logic circuit in the camera, which performs the selected OSD function. I must say, I would much rather have a software controlled camera remote setup, but this simple solution is all I could come up with in a short time. I think as an afterthought, one of the IP compatible cameras would make a better camera choice, I don’t know.
Getting Started:
I went online and ordered the following hardware items for my project. You decide what length cables you need. They may be available at a local Radio Shack store. Make a list and find what you need first.
1(ea)…25’ MD6 Cable M-F (six conductor ‘mini din’ pre made cable)
1(ea)…3’ MD6 Cable M-F (cut in half to make camera/hand box pigtails)
1(ea)…Project box plastic/aluminum u-pick size
5(ea)…Pushbutton switches to fit in box
1(ea)…Grommet
4(ea)…Rubber stick on feet
You will want on hand the following items:
Soldering Station/Iron/solder
Good lighting/work bench
Reading glasses
Wire cutters/dykes
A good set of small magnetic screw drivers
A drill motor and drill bits
Disassemble the camera:
Remove Top Cover and rear cover
Remove screws from back assembly
Circuit card removed from back chassis. Hold CCA securely in vise or other device.
Be very careful with the circuit card.
Wire It!
‘Close-up’ of the card…note solder pads next to pressure switches. The black marks indicate where each switch wire can be soldered…there are two pads available for each switch but pick one to solder the wire to. The other two pads on each switch are at ground potential.
You can solder wires to board while still in the back chassis if you want…route cable out as shown. Use the shorter cable cut in half to make this pigtail with a female connector. When you establish the location for exiting cable notch, mark it on the back chassis remove the circuit card and wiring, and cut out unwanted wedge of metal. You can use a drill bit to start the hole. Then finish with your hand tools, filing the rough edge when you are through. Carefully remount the card.
You don’t have to install the original plastic button assembly unless you want to maintain the original on camera OSD control function. I put mine back together so it will work the camera also. Just be sure if you do put the plastic buttons back in the camera that you leave space between your new wires for the three plastic feet to contact the three holes in the circuit card. Cut a slot in side of back chassis as shown to route wires from the camera. Reassemble the camera and test the function of the camera…hopefully it will still work. If not you have some trouble shooting to do inside.
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Shown above is my completed camera showing the gray remote pigtail with a female mini-din connector and the black power cable. The 25’ cable I ordered will connect to this pigtail with a male connector and attach to another pigtail at the remote control box. So on to building the hand box.
The Hand Box
You will start by gathering all of the parts necessary to build the remote. They will be a small project box, and five momentary switches along with cable grommet and the rubber feet if you want them. Take the front panel off the project box and drill the panel with the correct size holes to mount the switches. The hole pattern should be in the same configuration as the switches on the back of the camera to allow intuitive tactile control of the camera…that is up down and left right, etc. They might be anywhere from ¼” to ½” holes depending on the switches you bought. Mount the switches and secure with the hardware provided. Now drill a hole to hold the grommet, which will allow entry for the pigtail cable. Install the switches to the front panel and the grommet with the pigtail to the box chassis.
Now you have to figure out which wire is which and wiring to the switches. The best way is to connect the camera pigtail you already built, to the hand box pigtail. Power up the camera with you power connector and check the monitor or pc for the display. By touching the exposed colored wires to the ground/shield wire of the pigtail, you can see what each wire does on the display. Mark down the result telling which color wire does what.
The first wiring you need to do is run a small bare copper wire through just one connector of each switch, it doesn’t matter which one you select so long as you wire just on of each. This will be the ground return wire for the remote.
Then solder all the ground wires to the switch tabs putting the correct color wire on the proper switch. I used 1brn, 2red, 3org, 4yel, 5grn, black is unused but can be used to provide 12vdc to power lighted switches if so desired.
Here is my completed hand control. Identify the switch/functions however you like.
Have fun with this, and clear skies!!!
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