[Ratracer]

Hi all I have several controllers with variuos controlls ie brakes, sensitivity, traction control etc but would like to add a choke switch preferably on the wire cables so that I can quickly change the max voltage for a technical section of track. Ideally also with a dial to dial in the desired voltage for the switch to use (ie 9 or 10 volts).

Are there any parts that I should consider that I could get from the local electorinics shop.

Regards

Ray
Team Thunderbird

 

[pfj]

Hi, you could use a 1 pole 12 position rotary switch with diode.s wired into the power lead from transformer to controller dependent on motor's used for diode rating amp wise eg. 1/3/6amp. phil.

 

[DR STICKY]

hi ray
each diode you add on phils rotary switch would give you a voltage drop of 0.6 of a volt
if you are in England/ uk try maplins for your bits
you need a
1 pole 12 way rotary switch order code FF73Q
and
diodes try 1N4002 1 amp 50v (don't worry about the voltage that's what it could handle) sorry have no code for these but maplins should be able to supply them or similar

hope this helps
Robbo

 

[mtucker666]

I have just completed this purchasing all the necessary bits from www.bitsbox.co.uk (very reasonable). I have added diodes running on both directions so that it works whatever the polarity of the track (thanks to Mick Kerr for that advice). Works a treat.

The only diff between this and a choke is the choke will provide you max voltage at full throttle whereas the diode will reduce the voltage at all times.
Matt

 

[300SLR]

Adding "Choke" normally means adding resistance not a fixed voltage drop.
If you want a voltage drop, diodes are a good answer.
The two feel slightly different when driving a car, either is good for taming overpowered cars.

1 amp diodes (1N4002, 1N4003, 1N4004 etc.) are good for standard home set type motors and a bit above. For motors taking substantially higher current you need higher current diodes.

QUOTE (mtucker666 @ 6 Dec 2011, 08:34) <{POST_SNAPBACK}>The only diff between this and a choke is the choke will provide you max voltage at full throttle whereas the diode will reduce the voltage at all times.
Matt
That's not quite right. There are two ways a Choke or diode can be wired.
1 So it reduces power all the time.
2 So it only reduces power on part throttle but still has full power when the trigger is fully down.
Both are widely used, either can be useful. It all depends on what you want to change about the way a car goes.

 

[scaleslotcars]

QUOTE 1 So it reduces power all the time.
2 So it only reduces power on part throttle but still has full power when the trigger is fully down.
Both are widely used, either can be useful. It all depends on what you want to change about the way a car goes.

You can easily put a switch in so you have a choice

 

[Ratracer]

Hi all thanks for the comments I will have a look at the components at the local electronics shop and see how difficult it is. I am in Australia so it is likely to be Jaycar Electronics. A christmas holiday job.

I run mainly NSR NINCO and ScaleAuto motors upto 30k but am currently looking at some of the Plafit 1/23 and 1/24 cars.

Regards

Ray

 

[Chicane Raceway]

Hi just to clarify, as im looking to make one as well, on Maplins, is it the glass diodes or silicon? excuse the stupid question im learning!!!

Kris

 

[300SLR]

Hi Kris
When using diodes to make a choke, all the motor current goes through the diode.
Diodes designed for milliamps (like most glass diodes) are not up to the job.
Rectifier diodes are designed to take amps rather than milliamps - so rectifier diodes are what you need.

For basic home set cars 1n4001, 1n4002 etc are suitable
For slightly quicker motors 1n5401, 1n5402 etc (3 amp) are better
If you are using even quicker motors the 6 amp P600 series are suitable.

You can get them from Maplin - or check our Rapid Electronics for better prices (by mail order)

 

[Chicane Raceway]

Many thanks, Christmas project me thinks!!

Talking of which, Merry Christmas everyone!

 

[Chicane Raceway]

Just finished putting by brake adjuster together, all looks good, would like to warn people that the 3a diodes are a little bigger than the 1a so they take a bit more work to keep tidy, something im not sure I've managed but im happy with it, cant wait to get to a track to test it now!!!

Also, this now leads me to the next bit, what is the best way of having adjustable sensitivity?

Any help is appreciated or a poke in the right direction!

Thanks

Kris

 

[pfj]

Hi, don't want to put a dampner on thing's but the diode's that have been suggested earlier are for reduceing your track voltage at about 0.7v these being rectifier diode's, for adjustable brake's it's better with Schottky rectifier diode's these have a drop around 0.3v giving a closer spaceing per step, for motor's up to boxer/nsr IN5817 are what's used but you say your useing 3amp are you useing alot hotter motor's as for adjustable sensitivity while useing resistor controller's as with parma eco's or plus the same rotary switch can be used but with 3watt wirewound resistor's these work fine with motor's mentioned you can get 7 or 10 watt if needed they are soldered seperatly as opposed to the chain of diode's and are wired to be in parallel with existing resistor I use a 35ohm value's starting at 180ohm down to 15ohm in nine step's with this set-up your reduceing the ohm's of the controller resistor your useing. phil.

 

[RichD]

The best way to change the sensitivity of a resistor controller is to change the resistor. If you wire another resistor, either fixed or variable, in parallel with the original resistor you can alter the sensitivity, but the controller will no longer have a linear response, it will tend to have a slower response the more you pull the trigger.

 

[Chicane Raceway]

QUOTE (pfj @ 31 Dec 2011, 21:16) <{POST_SNAPBACK}>Hi, don't want to put a dampner on thing's but the diode's that have been suggested earlier are for reduceing your track voltage at about 0.7v these being rectifier diode's, for adjustable brake's it's better with Schottky rectifier diode's these have a drop around 0.3v giving a closer spaceing per step, for motor's up to boxer/nsr IN5817 are what's used but you say your useing 3amp are you useing alot hotter motor's as for adjustable sensitivity while useing resistor controller's as with parma eco's or plus the same rotary switch can be used but with 3watt wirewound resistor's these work fine with motor's mentioned you can get 7 or 10 watt if needed they are soldered seperatly as opposed to the chain of diode's and are wired to be in parallel with existing resistor I use a 35ohm value's starting at 180ohm down to 15ohm in nine step's with this set-up your reduceing the ohm's of the controller resistor your useing. phil.

ahhh, so I might have "off-half-none" over the first three clicks?? LOL oops. I am using anything from scaley standard to flat 6/scaleauto 21k

 

[pfj]

Hi, if you go too low on resistor value it does go non-linear I started useing wire-wound pot's to give a stepless change but with pot's if you get a short you can burn out part's of the track plus there's nothing to stop it being turned to far down that's why it's best useing resistor's 15ohm is my lowest at present which give's a overall value of around 16ohm from the controller but you still have the feel that original resistor give's you it's hard to explain untill youv'e tried one.Some people have built them and not got on with them other's the reverse iv'e made 5 at our club and 3 other racer's making their own as a simple,basic,fairly cheap £18 minus controller you can reduce the number of resistor's to make it cheaper I think there a great first introduction to what adjustability provide's. phil.

 

[pfj]

forgot to say price include's adjustable brake's, cable, and plastic box it's contained in. phil.

 

[stoner]

would it be any trouble to put up a wiring diagram 12 pole with 6amp diodes for a completely clueless electrical moron. i dont even know where you,d wire it in. thanks john.

 

[Chicane Raceway]

Gotta say a massive thanks to all that have contributed in this topic, i now have a finished piece, cant wait to test it early Feb at East Devon.

Thanks people

 

[pfj]

Hi, not able to put on any diagram sorry but presuming your wanting voltage reduction ( but brake diodes are connected to the switch in the same way ) with useing 6amp only problem is the size of the diode and it's wire with 1 to 2amp diodes you can easily connect two of the wire's per loop of the switch contact, iv'e used 3amp's before but wire thickness only allows one to be soldered thru the loop the other being soldered either to the out side of the contact or the other diodes wire, hope it's not getting to confuseing so far normally the diodes wires are cut at around 5mm and soldered fairly close to the contact's but with the larger dimension's I would suggest working with the full length of wires at first to see how they sit round the switch. Right first you want to bend outwards the switch's contact's 3 to 4mm from vertical to end up with what I call a crowned look this will make gap between contact's slightly wider giving a bit more space to play with, next you want to bend the diodes wires at a rightangle to the body of the diode to make the look of a elongated U ( with diode at base ) do this to all the diodes your useing they should have a silver coating at one end this show's which way the voltage is flowing, they say a picture speak's a thousand word's probbably close by time finished anyway looking at the back of the switch it's numbered 1 to 12 you want to start at 1 placeing the first diode's wire thru the contact loop with the silver end of diode to the right so that the other wire silver end is going to go thru loop 2.You can push the two wires thru the loops to see how far they will go then place another of the diodes in same orientation as before above the contacts 2 and 3 to see if there's going to be enougth space if not pull the previous diode out a bit at a time untill you feel there's a suitable gap you can bend the diode's up or down onece there all soldered anyway to give space between them if your ok with position then solder the first diode in loop 1 remembering to have silver end to the right leaving the diode's other wire un-attached place wire of second diode same way round in contact 2 leaving it's other wire as the first continue this with the number of diode's your useing with the last diode it's other wire can be soldered thru the next contact loop then solder the remaining loose wire's to their position's second wire first diode to 2 second wire diode two to 3 third to 4 and so on sorry but will have to continue at later date not my computer and need to exit the building will try to finish tomorrow phil.

 

[stoner]

thanks phil, i had to read it about 7 times to let it sink in [i,m that bad with electronics] soldering chassis, turning wheels ect i,m not bad at. but anything more than hooking up a motor brings me out in a cold sweat. cheers john.