Posted January 28, 2006 09:28 PM
Have new hardwired system, Bell telephone 6pr x 22 gu wire in shielded cable, 64 ohm res. in the start loops.
Finish hut is beside chairlift and when the chairlift is running we get a start signal when the wand is opened (good) and when it closes (bad)! AS well we get about 25 start pulses when the chair starts or "stalls". How far from the lift do the cables need to be. When the lift is closed all is well. Any suggestions? HELP

Are you using an optocoupler?

Try operating the S4 without a power supply and without the connection to the PC.

If the problem persists than the start pair will need to have an optocoupler installed.

If the problem goes away then the optocoupler needs to be installed between the S4 and the PC.

There are several types of optocouplers available for these types of issues. PST stocks them in new and demo models.

We had a problem just like that caused by the three phase lift motor going bad. It wasn't related to the start wand and timing cable however. Our false start impluses (every second) were coming in via the electrical power (480v stepped down to 120v at the shack). Going to batteries cured the problem. A new lift motor the next season got us back on the power.

As I do not know what an optocoupler is I will assue I am not using one. Yesterday (race day) I utilised 12vdc to the s4 and a (yes new, 0530am) cat 5 cable run. I did notice that the cable run we are having trouble with was no longer picking up the false signals but the 60hz humm on the headsets rebdered them unusable on original wireing. All OK on CAt 5 run down race course though. So now we need to "fix" the hardwired sys. What is an optocoupler?

Ah, Grasshopper....you have much to learn. An opto replaces the physical connection between the timing equipment & the hill with an optical relay.

Ski hill wiring is one of the best natural antennas on the planet. It picks up ungodly amounts of static and, as you've observed, EMF. It also sometime carries ground mis-match to the point where your equipment can burst into flames (I've seen it happen with my own eyes). You must use both a multi-channel opto and an RS-232 opto to isolate the timing equipment from the hill and the computers from the timing equipment.

ALGE makes a nifty device called the OC-18, which you can buy from Phoenix Sports. TAG Heuer also makes a nice one:

http://www.tagheuer-timing.com/products/otheraccessorie...7C-B291-AD2A0C42DFD5

At World Cup we use an industrial-strength monster opto called The Blinky Box. It is not available to the public, and I can't tell you any more about it .... otherwise I'd have to kill you.

small hint: if your hard wire passes too close to the electrical hill wiring you can pick up interference, specially when the electrical motor decide to go thru a stop/start cycle.

I have used the 18 channel Alge opto isolator for years on the hill side, and B&B Electronics makes a couple of different isolators for the RS232 between the timer and the PC.
http://www.bb-elec.com/product_family.asp?FamilyId=1&Trail=4&TrailType=Main

They also make or sell a bunch of other pretty handy stuff. I have used their serial to ethernet converters and also the radio modems.

Allan Coppock