25 replies to this topic

[bw1721]

I was given an old Omni controller. The guy said he used for HO racing I'd say back in the '90s. It has ten bands including full off and on, two adjusting knobs (one for brake and other like a speed when pulling trigger).

I've never had an adjustable controller but it's better than the Parma I have.

My question is will the braking vary when running 12 volts to 20 volts of track power? The track we race at has a power supply and we race Mega-G AFX at 12 and G-Jets and G-3s at 20v.

Also is there anyone that could do a update to this controller? I tried to upload a pic but had trouble. The brake pot has writing that looks to be 3 ohms, then 2.04a. The other knob has ,,026t332r101b1a49829roc stamped in it. There's six diodes in all also.

Thanks for any help.

[Ramcatlarry]

Omni with knobs? Switches are normal, some special mods for HO??

[HarV Wallbanger III]

I have this one that I'm putting on eBay soon. Does it look like this?



John modified this for me but I needed a controller for home racing and this is just too much for that. Works great, and signed by John Cukras!

[bw1721]

[Mopar Rob]

Ummmm, that's not an Omni. Looks more like a Ruddock and not the original that only had seven bands.

PM Dan Ruddock or Google to see if he has a website.

[Dan Ruddock]

Yes, that is one of mine and intended for 1/24 racing. I can re-cal and change the brake pot for HO use. Contact me for for details.

Dan

[32Deuce]

For positive gate track wiring should the indicator diode on the Omni Flex be red or green? It doesn't say in the instructions, only that the color may be "different" from a negative gate to a positive gate track. My two Omni Flex controllers show red for a positive gate track but, I have a friend who has a cheaper Omni controller that shows green on positive gate. Is this normal?

Z

[Mopar Rob]

Mike:

It's been years, and I mean years, since I had one, but if I remember correctly, Green = Positive Gate or what most tracks are wired, and Orange is Negative Gate.

[Paul5097]

On my Omni, the LED glows green when the white wire is connected to power (+) and the red wire is connected to common (-), positive gate. When I reverse the connections, red to (+) and white to (-) the led glows red/orange.

[Ramcatlarry]

It also depends on who soldered on it last. The LED is a standard Radio Shuck part and can be installed either way and is not consistent in either color... would be nice if it was. Does not matter since all Omnis will run on either (+ or -) polarity, unlike most transistor controllers.

[32Deuce]

I'm a little confused here since wiring is NOT my forte. I was mainly using the old Omni as a test unit to see how a track was wired. The track in question is a home routed track wired negative polarity (supposedly the "old" way with the red going to positive and white to negative). And both my Omnis' diodes showed green. When the track wiring was changed to positive polarity (said to be the modern way to accommodate electronic controllers, red to negative and white to positive) and
(this according to Professor motor's wiring diagrams) the diodes glowed red on both controllers.

Then I'm reading Paul Pfeiffer's "Alpha Slot Track wiring" and it says positive gate was used for 30 years prior to what is used now "Negative Gate" ... that's backwards, isn't it? very confusing.

Is the term positive "gate" the same as positive "polarity?"

Z

PS: Both my Omnis are the "Flex" versions. Maybe the diodes were put in backwards on these, verses the cheaper Omnis?

[Dan Ruddock]

Yes, positive polarity and positive gate are the same thing. It can also be referred to as negative ground (the same way your real car is wired).

This has always been the standard and don't let anyone tell you otherwise and I am not just referring to slot cars but all DC circuits.

Dan

[32Deuce]

Then if I understand this correctly, Positive Gate/Positive Polarity is what is needed for almost ALL electronic controllers and is wired as WHITE=goes to +positive on battery, BLACK=goes to right hand (+)braid, and RED=goes to -negative on battery and Left hand (-)braid?

How can Paul Pfeiffer, (according to his "Alpha Slot Track wiring" manual) have a major commercial track facility that runs negative gate?

Unless, he MEANS "negative ground."

Z

[Dan Ruddock]

Yes, you are understanding correctly how a positive gate/negative ground track is wired. Paul has some strange ideas and I would not use what he says as a standard. I too have read his ideas about track wiring and I don't agree with them and no, he is not talking about negative ground.

I think part of the problem is whoever came up with the color code we use in the USA is a moron. The power post (+) should be red and not white. The brake/ground post (-) should be black and not red. The controller output to the gated/non ground braid should be white. This makes a whole lot more sense than what we are currently using compared to the world of electronics.

Dan

[32Deuce]

Thanks, Dan, for the confirmation and for the life of me I can't understand how Alpha Raceway would accommodate electronic controllers, not to bash Paul maybe he has a way to do it, I don't know but, with that publication he's selling, preaching totally opposite what everyone else's standard is can be very confusing. I DO think though that most of the rest of the ideas in there are good ones though a lot of it is overkill for a home track.

So, my original problem of the different colored Omni diode according to track wiring type is probably just simply that the "Flex" controllers I have, have the diode soldered in the opposite way of the rest of the Omnis.

The color hookups are strange. I guess the time to change that would have been when everyone switched to positive gate. Too late now.

Thanks, all!

Z

[Dan Ruddock]

Everyone did not switch to positive. Other than alpha most tracks from the beginning were positive so he switched to negative and went against the standard.

Some tracks ended up negative from people who did not pay attention to the braid connections and when the car went backwards reversed the power supply which changed the track from positive to negative. The right way to reverse the cars direction is to reverse the braid connections but that is more work and when all we used was resistor controllers it was not an issue.

When I came out with my controller in 1993 which was when transistor controllers became popular I would guess that only about 15% on the tracks in the USA were negative.


Paul was never a fan of transistor controllers so leaving his track negative suited him.

There is no advantage of one way or the other way other than standardization.

Dan

[32Deuce]

OK, I was stumped a bit because in my area with the clubs, negative gate was what was used from the early days on up until electronic controllers came along and then the transition started. I don't know what the commercial tracks were using here in the old days but, I'm sure they were all positive as you say. I remember a couple of guys installing switches on the drivers panel on their home tracks to reverse the direction if they wanted to run a race the opposite direction. I guess now that wouldn't be possible.
Z

[HarV Wallbanger III]

"Maybe the diodes were put in backwards on these, verses the cheaper Omnis?"

Dan are not diodes all one way gates and can not flow in the opposite direction??

[Dan Ruddock]

"Maybe the diodes were put in backwards on these, verses the cheaper Omnis?"

Dan are not diodes all one way gates and can not flow in the opposite direction??

Yes diodes are one way gates but it is much easier to make diodes dual polarity than transistors. All you have to do is reverse parallel two diodes and now it will flow both ways. Dan

[Dan Ruddock]

I remember a couple of guys installing switches on the drivers panel on their home tracks to reverse the direction if they wanted to run a race the opposite direction. I guess now that wouldn't be possible.
Z

It is possible, I have done it with a double poll double throw switch on my HO track. The switch reverses the tap connection to the rail. Dan

[RomanK]

I'm pretty sure I heard that Paul at Alpha has changed his track wiring to the more conventional positive gate.

[Dan Ruddock]

I'm pretty sure I heard that Paul at Alpha has changed his track wiring to the more conventional positive gate.

That is good news if it true. Dan

[Ramcatlarry]

Track polarity was VERY inconsistent in the 1960's. I have several of the early transistor controllers that had FOUR hook-up wires....you literally had to tap to see which (3) wires to use of the four. Most Cris Dadds' tracks have been wired NEW as neg gate and Ogilvies as pos gate. Since the Ruddock/Difalco innovations years of the 1990's, most tracks have been converted to Pos gate.

LED's are diodes, so are bridge rectifiers. They just have more packed into the space. Omni controllers use bridges of 4 diodes of which only two are in use at any one time, given the polarity of the source power. The bi-colored LED is also a dual diode with a unique color for each polarity direction.

The Prof Motor diode controller also has an accessory kit of individual LED's that can be used to check polarity and power to a lane for any controller.

[32Deuce]

Good info Larry. The instructions I still have that came with my Omni Flex talk about the "Track Information" LED and states that it be used to see #1 if power is on or off, #2 whether the tracks brake circuit and brake fuse are working properly and #3 which polarity the track is wired with. They explain the obvious functions and go on to say that:
"The track polarity will determine which of the two (red or green) LED colors will light. Either color is OK."
I gathered from that and the info given here that the colors would not necessarily be "designated" and I have found that out through experimentation. If you want to check track polarity with the Omni controller you have to first know which color your particular Omni shows for negative or positive gate. As I said earlier, I have two Omni "Flex" from the old days which I think was the top of the line then at $250 retail. They both show RED for positive gate and GREEN for negative gate. Many of the cheaper Omnis show just the opposite colors so I guess the theory of them possibly being wired in backwards or maybe varying component brands could be true. Instead of using this to check polarity, is there an easy way to check it using a multi meter?
Z

[Chris Dadds]

Track polarity was VERY inconsistent in the 1960's. I have several of the early transistor controllers that had FOUR hook-up wires....you literally had to tap to see which (3) wires to use of the four. Most Cris Dadds' tracks have been wired NEW as neg gate and Ogilvies as pos gate. Since the Ruddock/Difalco innovations years of the 1990's, most tracks have been converted to Pos gate.(.......)

I remember the 90s and trying to shake out which gate was going to be the standard. As a builder it was a little frustrating trying to find out which way the buyer wanted the track wired so I'd build the wiring harnesses in a way that would let me just hook up one lane and see if it worked with the buyers controller. Except for the few where the buyer wanted to scrimp to save a couple hundred bucks, I wired them so that every wire to the drivers posts is the same length as all the others and every lead to the taps is the same as all others, and every stretch of braid was the same. Hence those sweeping section lines I used to put on them. I've noticed that when they get moved they usually get re-connected with the taps running strait across the track, and the positive attached right next to the negative, and people griping about what to do with the extra wire. If you're not going to worry about the resistance of the wire and the braid why even bother to use multiple taps? You really can't overcome resistance with capacitance. :-)

Just musing...

Enjoy!
Chris
(who ran across this this thread while looking for a circuit diagram for a controller with an adjustable response curve)