8 replies to this topic

[Mark Onofri]

Here's something a lot different that you don't see everyday.

I'll post more pics shortly.

 

 

[Mark Onofri]

I'll post the instructions later.
 
Anyone ever used one of these?
 
Looks and feels like #5 of solder on the connections.
 

[Bill from NH]

I never owned one, but I think they were popular in the '90s. The one in your photos looks new. Is it yours?

[Bill Seitz]

I haven't used one, but this is basically a diode controller using bridge rectifiers. Diode controllers use a series string of diodes using the .6V voltage drop across each one to create a throttle step. Because bridge rectifiers have diodes arranged in both polarities, they enable the Omni to work in either polarity. Realize that this is a very early entry into electronic controllers noting that it's only 9 bands and was primarily competing with resistor controllers. It may have seemed like it was adjusting to all levels of motors because I'm sure it was better than the resistor controllers in this respect. However, diodes still increase voltage drop as current increases, so they aren't as effective in adjusting for different motors as a transistor controller with typical sensitivity control. The sensitivity control also lacks the resolution and variability of a transistor controller, since the sensitivity is being changed by switching additional diodes in and out of the circuit. A bridge rectifier having 2 diodes in series offers a 1.2V step. That's pretty coarse resolution. Of course, compared to a resistor controller that likely had no sensitivity control and was greatly effected by changes in load current, the Omni could be a big improvement. Today, it's far surpassed by transistor controllers. I'd relegate it to a conversation piece and historic collectible.

 

Of course, I was recently told of a wing car racer that's still using a 7-band Difalco. I didn't know Jim made a 7-band controller - missed that one.

[slotcarone]

I have a Cidex Omni. A similar but different design. They were used with a Parma Turbo controller and you converted it to the Cidex. We sold many of them and did the conversion at Westchester Raceway back in the '90's. A great design that myself and many others used for flexi and up to Group 27 classes. I used mine for many years when we first started Retro racing. I had an adjustable brake on it. Still works great.

[Mark Onofri]

The adjustable break is something that I've been hoping will be better when using the new bread of insanity powerful magnets. Having learned to negotiate(sometimes)the corners by costing into them,I've not been able to do that with these magnets.
Yes Billnh,I purchased it new but I've yet to use it. I believe that my >=.7ohm external controller that had been my favorite,with a lot of sentamental value has been stolen,so I dug this up looking for it.

[Jim Difalco]

I haven't used one, but this is basically a diode controller using bridge rectifiers. Diode controllers use a series string of diodes using the .6V voltage drop across each one to create a throttle step. Because bridge rectifiers have diodes arranged in both polarities, they enable the Omni to work in either polarity. Realize that this is a very early entry into electronic controllers noting that it's only 9 bands and was primarily competing with resistor controllers. It may have seemed like it was adjusting to all levels of motors because I'm sure it was better than the resistor controllers in this respect. However, diodes still increase voltage drop as current increases, so they aren't as effective in adjusting for different motors as a transistor controller with typical sensitivity control. The sensitivity control also lacks the resolution and variability of a transistor controller, since the sensitivity is being changed by switching additional diodes in and out of the circuit. A bridge rectifier having 2 diodes in series offers a 1.2V step. That's pretty coarse resolution. Of course, compared to a resistor controller that likely had no sensitivity control and was greatly effected by changes in load current, the Omni could be a big improvement. Today, it's far surpassed by transistor controllers. I'd relegate it to a conversation piece and historic collectible.

 

Of course, I was recently told of a wing car racer that's still using a 7-band Difalco. I didn't know Jim made a 7-band controller - missed that one.

Bill, you are cheating me out of 3 wiper bands! I made 10 band external resistor controllers. Back in the early 1990's when the Omni came out the owner asked me to build them for him while I was already building my own external resistor controllers. I told him I would consider it and he gave me one of the original units to play with. I had no intention of being his employee and I still have the unit to this day. His company lasted about 3 years or so.

[Mark Onofri]

What's your take on it Jim?

[Bill Breck]

The adjustable break is something that I've been hoping will be better when using the new bread of insanity powerful magnets. Having learned to negotiate(sometimes)the corners by costing into them,I've not been able to do that with these magnets.
Yes Billnh,I purchased it new but I've yet to use it. I believe that my >=.7ohm external controller that had been my favorite,with a lot of sentamental value has been stolen,so I dug this up looking for it.

 

Try turning the brake all the way off to get maximum coast and then adjust it upwards if you feel you need more brakes. This is what I used to do for the Wednesday night LMP race at Speedy's.