Thomson-Saginaw Ball Screw Reed?

[RT-Cat]

My Thomson-Saginaw worked without any problems moving the BUD with a G-Box to exactly where it should move to. Not having that much luck with the ASC-1. Over runs and under runs have been the problem. No slop in the actuator or fittings. It has been stated the ASC-1 is missing counts from the actuator.
So, can/could this be the reed switch and magnet? What about the wires to the actuator? What about....????
A search for over an hour found only Skyvision sold the switch but you had to wait for who knows how long. May be on a slow boat from China.
Any thoughts on why it did work and now it does not? Does the ASC-1 need more "powerful" pulses?
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Picture shows what I have out there.

 

[FaT Air]

Over run - missing pulses - switch or lossy/noisy line.
Under run - bouncing switch producing what appears as extra pulses
Optical would be the most reliable switch type, but?????

Should be a braid over the sensor wires if using a ribbon cable. Ground it on one end only. Place a .001 to .01uf cap across the sensor. another couple from each sensor lead to GND could also be tried(in conjunction?).
Digikey magnetic reed switch Mouser Thomson

 

[. Raine]

Over run - missing pulses - switch or lossy/noisy line.
Under run - bouncing switch producing what appears as extra pulses
Optical would be the most reliable switch type, but?????

Should be a braid over the sensor wires if using a ribbon cable. Ground it on one end only. Place a .001 to .01uf cap across the sensor. another couple from each sensor lead to GND could also be tried(in conjunction?).
Digikey magnetic reed switch Mouser Thomson

This is what Primestar31 and Brian suggested I try to do with mine, but I haven't been able to get the time to do it yet.

 

[FaT Air]

Should also mention. If it's motor noise causing problems, sometimes, a healthy cap across the motor leads. But would have to be a non polarized variety. 100uf at minimum. Bigger is better. But grounding the braid should attenuate this sufficiently. If not clean/replace brushes and clean armature.

 

[Magic Static]

Brian's recommendation is a .01uf capacitor across the motor leads, not the sensor.
http://www.satelliteguys.us/threads/330862-ASC1-and-AJAK/page5

 

[FaT Air]

If it's a bouncing switch. a cap across the sensor may 'fix' it.
http://www.ikalogic.com/de-bouncing-circuits/

 

[KE4EST]

RT, use shielded cable if you are not already and try the suggestions that Brian, mentioned before and see what happens. Quickest thing to try is grab you some caps and have a go with those.

 

[RT-Cat]

Over run - missing pulses - switch or lossy/noisy line.
Under run - bouncing switch producing what appears as extra pulses
Optical would be the most reliable switch type, but?????

Should be a braid over the sensor wires if using a ribbon cable. Ground it on one end only. Place a .001 to .01uf cap across the sensor......

Uhmmmmm, electrolytic or disc?

 

[FaT Air]

disc - Who know, does the local RS still carry them? I don't know, I usually order from digikey, sometime even 'pick up' at the office.

 

[KE4EST]

Some Radio Shacks do some don't. Most aren't hanging on the walls anymore though. They are in drawers in the back.

 

[turbosat]

rt-if the sensor is that thing under the magnet-wheel, that says "super sensor" on it, I may have one of those here. Brand new. Let me know if you think it would help, I'll try to locate it and make a picture for you.

 

[richyrich]

The sensor is very sensitive to overvoltages; including accidently connecting it for even a second to 12vdc instead of the 5vdc; or static from the rug/body when the wire is being touched during connect/disconnect. The sw in the picture can be taken apart and any 5vdc glass tube type w/leads from can be used and glued into the housing. The glass tube is found for around 2 dollars; usually at security parts suppliers (they use them for trip sw's on doors, windows, etc).

 

[Magic Static]

The sensor is very sensitive to overvoltages; including accidently connecting it for even a second to 12vdc instead of the 5vdc; or static from the rug/body when the wire is being touched during connect/disconnect. The sw in the picture can be taken apart and any 5vdc glass tube type w/leads from can be used and glued into the housing. The glass tube is found for around 2 dollars; usually at security parts suppliers (they use them for trip sw's on doors, windows, etc).

MMMM not really. The sensor circuit is 12V DC @ about 5 milliamp . The glass magnetic reed switches I use are rated at 200v 3~10 watts. I would recommend a Flex-14 (Hamlin brand switch) from Digi-Key PN HE556-ND. about $.65 This is a very versatile switch and fits well in many applications. However replacing the glass switch in these sensors can be a challenge. And the glass is easily broken by bending the rigid leads. Hence the "FLEX" 14 has bendable leads.

 

[Bongu]

Summit source also sells the super sensors.

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[RT-Cat]

disc - Who know, does the local RS still carry them? I don't know, I usually order from digikey, sometime even 'pick up' at the office.

Not a problem finding one. Just went to the electronics stuff(junk) box and pulled one out. Yesterday it was 58 degrees outside. Warmest since very early November. But being Michigan, it is 32 today. Next "warm" day I will try and see what happens. Maybe late June........
.
Turbosat,
I will let you know when I use cap and see what happens.
Thanks

 

[y2k2000]

Use common door/window alarm switch. Mod sensor holder to hold door/window alarm switch and use glue gun to glue it in place.
PROBLEM SOLVED. I have same actuator with ASC1 and had similar problems. Also check censor wiring end to end for broken wire.

 

[richyrich]

MMMM not really. The sensor circuit is 12V DC @ about 5 milliamp . The glass magnetic reed switches I use are rated at 200v 3~10 watts. I would recommend a Flex-14 (Hamlin brand switch) from Digi-Key PN HE556-ND. about $.65 This is a very versatile switch and fits well in many applications. However replacing the glass switch in these sensors can be a challenge. And the glass is easily broken by bending the rigid leads. Hence the "FLEX" 14 has bendable leads.

you are magic-static so I dont flame anyway. wheeling is your profession then you can call me wrong; but if you put your meter on it; it will tell u what it is doing. Another solution is to slow the count down by changing the magnet wheel at the arm to slow the pulses down, thereby halfing the counts (or thereabouts); which you must read the magnet by seeing how many it is trying to put out (this require. magnet wheel reader card (cannot help u there either). 12 vdc is required for most optical switches; plus a pulser/gnd setup. It is why the 12vdc blows up a read switcher which relys on pulser/gnd only. But only because static can go upwards of 10kv. Receivers are rated at 200v and 10 watts. I do wish you well however u can; U R right to debounce with electrolytic cap aim at gnd too.

 

[Magic Static]

Yes I know what I'm talking about and I have designed and built several position sensors for mine and others C-Band dishes. Magnet wheels and reed switches. I can show you scope patterns as well as voltage readings on these in operation. You could take your own advice and put a meter on it

 

[Titanium]

A new ASC1 test firmware file is available for anyone wanting to test a new sensor sampling routine for minimizing the "bouncing switch syndrome". Drop me a PM with your email address if you wish to test and provide feedback.

Also, lightning season reminded me of a problem from the good ole days of C-band service calls.... voltage spikes from near-by lightning or even static discharges would mess with the positioner counts as these voltage spikes are interpreted as an actuator movement. Added a routine to the ASC1 test firmware file that disables the sensor circuit if the actuator is not in use. The actuator sensor circuit is immediately activated when the ASC1 front panel, remote control or connected STB initiates a command then times out after the movement is completed.

Let me know if these updates improve your life or ???