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Thread: Electronic choke vs. wire choke

  1. #1
    Join Date
    Feb 2009
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    Electronic choke vs. wire choke

    Hello everybody (my first post here).

    After reading lot of threads about chokes, I'm still wondering if it's possible to compare a wire choke with an electronic one...
    OK, I try to explain better (sorry, english is not my mother language)

    I got from a friend a YayGee Linear 200 controller; it is equipped with the voltage limiter described on JayGee site (http://www.jaygeeracing.com/files/Bu...onic_Choke.pdf) but the choke pot is broken, so I have to change it.
    The pdf says you may use either 100 and 250 ohm pots and I have no idea which one to use, so I'm wondering if it's possible to roughly compare ohms with feet (i.e: 100 ohm is like about XX feet of 18 AWG wire, etc.)

    Thanks.
    Marco

  2. #2
    Join Date
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    I don't know how to put it in feet, but with the 100 ohms the maximum voltage will be reduced around 15%. With 250 ohms it will be around 32%. To put it clearer, with a 12V supply you will have a maximum of 10.1V and 8.2V approximately. Both cases with the pot set at maximum resistance.
    You will also have an initial reduction with the pot set to zero, due to the voltage drop in the transistor. That's the reason why you need the switch to eliminate the choking action.
    I've measured this is my controller and it's around .3V. I've obtained this values with the controller connected to a power supply an no motor, so it might change a little bit when you are driving a motor, but it will give you an idea.
    This works a little different than a wire choke, where the volts reduction is dependant on the amps drawn by the motor.

  3. #3
    Join Date
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    St Charles, Illinois, USA
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    2,319
    The proper ohm rating usually depends on th type of use the controller gets:
    HO high ohm
    1/32 homeset mid high ohm
    1/24 commercial mid low ohm
    1/24 commercial high power low ohm

    pick a use and a range.......Jeff from JayGee will probable clear it up.
    l.d. kelley, M.A. Ramcatlarry@aol.com

    60 year pin 1959-2019
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  4. #4
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    Guillermo,
    thank you for the explaination; so I understand that a comparison between wire & electronic chokes would make sense only for a given motor.
    For the record, I'll try first with the 100 ohm pot, as 15% voltage reduction seems enough to me.
    As I have to make major works on the controller (I'm left handed so I want to move the brake and sensitivity pots on the right side of the board) I'll install, too, a second toggle switch to turn on-off the blast relay independently from the choke.

    By the way, I fell in love with the "16 Position choke with only 4 Relays" project; I don't know if I really nead it, but IMHO the project is so elegant it deserves to be built anyway ; did somebody try to add a wire choke to the Linear 200 controller?
    I imagine I need to know where are located the tap points on the power module...

    Marco

  5. #5
    Join Date
    Jun 2002
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    Paonia, Colorado
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    Otello,

    I'm pretty sure that wire chokes are not visible to the controller regardless of which type you have. Simply clip them in between the controller white clip and the white post.

    I race a lot on flat tracks and I love my wire chokes. I've never used a voltage reduction choke, so I can't comment on them.

    Gugu feels that it is very important to be able to turn off blast relays when using a choke. I've not found this to be a problem, even in 1/32 F1 ES, but then again I'm lucky to make B-mains and he's a many time world and national champion.

    2 additional comments:

    * while chokes function the same for wing cars and for scale cars in a physics sense, I think that the use is a little different. For flat track racing, I try to run a motor that is a little too fast for the track that I'm running on, then I turn up the choke until the rear end stops breaking out hard when I get on the power a little too early. I usually also add a little bit to whatever I'm running when I'm on red or black.
    * a second use for chokes for me is to turn up the choke when a race gets very rough or I start falling out even more than usual. I find that this helps a lot, but it is rarely mentioned in discussions about chokes.

    Greg

  6. #6
    Join Date
    Apr 2007
    Location
    Mount Vernon, Indiana
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    89
    Quote Originally Posted by Otello
    As I have to make major works on the controller (I'm left handed so I want to move the brake and sensitivity pots on the right side of the board) I'll install, too, a second toggle switch to turn on-off the blast relay independently from the choke.
    Marco
    I'm left handed too and I've done that modification to mine. It's a good thing that you have the numbers on both sides of the circuit board in JayGee controller.
    If you look at the article in JayGee web site you'll see that I use a double pole switch to eliminate the blast relay at the same time you include the pot resistance.
    This helps me a lot. I initially made this choke to reduce my speed in break-out style races because my cars are faster than the break out time.
    We race crash and burn also, so when there is a track call I just flip the switch too max speed for that lap because I know I will not break out.
    Then, when I cross the lap counters, I flip the switch again to go to reduced speed below break out.

  7. #7
    Join Date
    Jan 2006
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    Model Car Race Center at Eden Mall
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    I have an HO Difalco with 100 ohm choke. Will this same setup work on 1/24 scale difalco using the same 100 ohm pot? They don't see it that way, only for HO scale. Of coarse they do custom choke work on the side.

    Just wondering.

    SCJ

  8. #8
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    Roma - Italy
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    Well, IMHO the simple fact that there are different opinion about disabling (or not) the blast relay when you insert the choke is enough to consider a separate switch.
    (Of course Guillermo approach is different as he use the voltage limiter for break-out races; on my side I didn't even know break-out races exist before reading his article...)

    Anyway, I tried first with a separate switch for blast relay placed in the third hole on the board, but I have to admit this way the board became a little too crowded, then I realized that I may use a single switch with 3 position (ON-OFF-ON); for example you may use the digi-key part number EG2458-ND in place of EG2455-ND, the cables connections are the same as in the original project, then you only need to bridge pin 4 and 6; this way I have the 3 options: Blast , Choke, Choke + Blast.

    Back to wire chokes, excuse me Greg: I'm a little confused by your comment (please understand I have no experience with wire chokes, so it's very possible my question is not so smart):
    if I place the wire choke between the controller white clip and the white post, the choke will be active regardless of the blast relay, so I miss why it's so important to disable the relay...

    Marco
    Last edited by Otello; 03-24-2009 at 09:24 AM.

  9. #9
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    Quote Originally Posted by Otello
    if I place the wire choke between the controller white clip and the white post, the choke will be active regardless of the blast relay, so I miss why it's so important to disable the relay...
    Nobody?
    Mmmmm, so I'd wonder if:

    1) nobody really knows why
    2) I tryed to discover the best kept secret in slotcar world
    3) my question is so stupid it's too difficult to reply in a polite way

    More seriously, in the meantime I tryed the electronic choke and discovered that electronic choke is nothing different from what's boldly called antispin or traction controll on some italian controller like the NSR (not the slot.it, which is a completely different animal, beeing software controlled); frankly speaking I do not like the feeling at all.

    Back to wire choke, while I'm building the "16 Position choke with only 4 Relays" for a friend racing Eurosport, I'm wondering if the wire choke concept could be adapted to less powerfull motors...
    I quote from an old post:

    Quote Originally Posted by Mr Tim

    [...]

    the more current your motor draws then the higher the voltage drop across the choke and the less voltage available to the motor. To illustrate again, dial in maximum choke. Now drive a Falcon powered car around. It feels almost exactly the same as it normally does. Why is that? It's because Falcons draw very little current so there are very few volts going MIA at the choke.

    This dependence on current draw is very very useful to us. That's because slot car motors draw a lot of current when we hit the gas coming out of a corner (or drive through glue), but much less current when running near full speed at the end of the straight. That means we get a lot less volts to the motor under hard acceleration, but nearly everything we want when the motor is running nice and free at the end of the straight.
    Now, let's imagine you want to build a wire choke tailored for a Falcon; I'd like to understand if it's just a question of size of the choke or of difference from minimum to maximum motor current drow...
    I mean:
    - first case: you may well build a wire choke with thinner and/or longer wire, it's just a matter of experimenting and finding the right size for that motor.
    - second case: you're wasting time, because the maximum drow of a Falcon is not different enought from the minimum to have a significant variation of choke effects coming out of a corner and at full trottle.

    Does it makes sense?

    Marco

  10. #10
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    You are correct, second case applies!
    Improving performance one hazardous material at a time.

  11. #11
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    Marco,

    You can also contact Jeff at JayGee. He,s a great guy, and is always there for any help or service you may need. Send him a pm or e-mail him and I,m sure he can help you with your questions. Just give him a little time to get back to you, as he has been very busy .

    Vic
    Keep your finger on the trigger ,and your eye on the slot

  12. #12
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    Vic,

    just to clarifie, I know for personal experience Jeff is a nice and helpfull guy and his opinion on the matter would be much appreciated.
    Fact is I have no problem directly related to my Jaygee controller; actually, I do NOT have a problem, just trying to better understand how chokes work.
    I'd say I learned more about controllers reading this forum than in my complete slot "career" - not too strange, if you consider you may find here the best experts on the planet - and I'd like to improve my knowledge.

    Marco

  13. #13
    Join Date
    Jun 2002
    Location
    Lake Saint Louis, MO
    Posts
    615

    Chokes

    Here's a really good thread that explains some of the differences between wire chokes and electronic voltage limiting chokes.

    http://www.slotcartalk.com/slotcarta...ad.php?t=21126

    Jeff
    JayGee Racing Controllers - 24 Bands of Bliss
    www.jaygeeracing.com

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