scalextric c7042 advanced 6 car power base

I think perhaps there is a good moment to take a step backwards from the conversation so far and look again at the question...

2 x C993's (equivalent to a UK C990 12v 1amp Unit) so in theory there are 12v and 1 amp to each track...

2 x C7024 (or equivalents) will output 15v and 4amps to each track...

in general speak.... OOOMMMPPH comes from the amps... Speed comes from the volts... I dont think the power input side is the issue here...

Firstly the APB is eating some power but as the PSU are regulated that doesn't steal any real voltage... So i don;t think its that either...

Jamie G Pointed out a similar thing when he switched from running analogue to digital after sending his C7030 away for modification so it may not be entirely APB related...

Enough waffle... Heres the point... a 30 Ohm resistor is low... It means that the amount of voltage regulation applied to the current is "less" than the standard "60 Ohm" scaley units...

As i Understand it the idea of using a 30 ohm resistor in a throttle is to make the car feel more "spritely" by giving more speed for less controller movement at the start of the trigger movement and finer control at high speeds.... reaching almost full speed at maybe 80% of the throttle maximum.... and the controllers often have a very light spring in them for finer adjustment.

This is way different to how a digital throttle works which is purely proportional.... a straight line response.... as you squeeze the throttle the more power is applied... Not reaching full power until the trigger is fully depressed (as long as they have been calibrated properly)....

So There will be a difference in feel... A car may have felt faster at say 60% of trigger movement witrh a 30 Ohm analogue throttle where it may have been gioving as much as 80% of the available power at that trigger position...

The scaley throttles are cheap... Lubricating the resistor with switch lube will help... Fitting better springs will help... but they are all a bit esoteric things to do...Just like with analogue spending £40 or so on a better throttle than the scalex originals will give better results (Truspeed two button digital a good place to start)... A £100 Slot-it SCP-01 will give you full dialability of throttle settings... and give you back the feel you are used to... But its a big cost!...

So practical things you MUST do if you havn't done already....

FIRSTLY: Make sure you have calibrated the throttles to the powerbase... and set the "trigger start point" to a setting you like... All software options in the APB (and explained in the manual)... This will give you the best from each throttle you have got... and make sure you keep them plugged into the same sockets as the APB will remeber the settings!!!!

SECONDLY: remeber the new throttles are linear and dont expect full power until you fully squeeze the throttle... SSDC allows throttle mapping to tune the throttles to your own tastes (i'm assuming is still in V5.... as i have not installed it yet)

ENSCA digital club upgraded to the Truspeed digitals recently and it helped shave 1.5 seconds of the best lap times over the first few weeks after they were introduced... In my experience I think you are chasing the "feel" of the throttles you are used to by looking for explanations in the "Volts and Amps" but i think its a red herring... The truspeeds don't have 64 individual connectors in the movement and seem to "read" the output based on a throttle curve of their own design instead of linear... they also have softer springs.... the outcome... all cars feel more responsive... No extra Volts, No extra Amps... just changes the "feel"... Digital guys used to the way the scaley ones work find it a tough transition (ME) but to the analogue guys the feel more normal!

hope that offers a different insight into a problem which has poppped up a few times recently... "feel" is a very personal thing.

QUOTE (MrFlippant @ 6 May 2011, 16:17) <{POST_SNAPBACK}>Ooh ooh! I think I know this one.. PWM!

The biggest difference between original analog and analog through the digital base is that the digital base is sending PWM (pulse wave modulated) DC. I think a dirty track will have more impact on a PWM signal from the digital base.

OK... I thought we were way beyond dirty rails.... But yeah PWM may well be the answer...

With analogue the power is "on the rails" all the time as a varied voltage...

Believe it or not PWM works by putting 12v to the rails in very fast pulses (100's (if not 1000's) of times a second) because of the architecture and some great experimentation from MR Flippant and some deep thought it is believed that the PWM signal is pulsed between lanes alternately not simultaneouosly... but what has that got to do with dirty rails?????

Well it probably goes like this... carbon build up caused by "arcing" leaves a deposit on the rails which interrupts current flow... With analogue Power every time there is good contact the full voltage at the rails all the power gets through... With a PWM signal if the time of good contact there is an "off" pulse then no current will pass as well as the times when there is no contact due to dirt.

There is no substitute to clean rails with digital... and that applies to analogue users of the APB... For digital users its about the transmission of data packets... For Analogue users its about recieving all PWM pulses.

Anyway onto the nicer feeling truspeed controllers... Here is the Link... They come with a choice of "wiper board" they come with the type one board as standard. You can change the throttle response by changing the wiper boards as you would the "resistor" in an analogue throttle... They come in Linear (as scalextric designed them), Type one which gives a more analogue feel... and type 2 which is an even bigger curve better suited to hot motors....

Hope that helps...

Good controllers though will not overcome poor conductivity on dirty rails... ENSCA also used INOX!

QUOTE (scalextricv8supercars.com @ 6 May 2011, 20:50) <{POST_SNAPBACK}>as i have a few parma economy contollers, as a cheaper option what do u think of the tru-speed digital kit sold by Pendleslotracing.co.uk....

Yeah thats a good question... I know nothing about these but looking at the picture from what i can see there is a multi point contact strip with each one "rated" by its own resistor...

The "track voltage" doesn't ever travel through a digital throttle... It just provides a 64 step resistance signal that is read by the APB... The "feel" you will get by fitting one of these will be much more parma like as you have the same spring and trigger travel... As to whether it is a linear resistance or a "modified" throttle curve i just can't say by looking at a picture... There is no detail on the truspeed website or on pendles either.

My advice... Buy one... Try it... at £16.50 its not a lot for what could be a great controller... If you don't like it well nothing ventured etc etc. If you have the "power" back by cleaning the rails then getting back to the parma's case and trigger will help things feel more familiar... Guess you won't use the Lane change/brake buttons being died in the wool analogue boy so may not be such a loss.... unless you get tempted by running more than 2 cars...

Oh to pick up on the variable PSU...... As long as you ensure that the "plugs" are wired correctly (reversing the polarity of the power input to an APB is very bad) should be no problem...

With analogue if you vary the voltage you can "adjust" how cars drive.... With the APB turn up the Volts and the APB bleeds the extra current off as heat.... turn the volts down and the "computer" will brownout becuase its getting the wrong voltage... PWM means only a 12V signal will ever reach the rails... chopped into "bits" to emulate the voltage the analogue car needs... No fun to be had twiddling power nobs!!! 2x C7042's will give 4 amps per lane... more than enough for most plastic cars... unless of course you have some 30K's to play with.... then maybe a big PSU may come into its own for big amp fun... oh no it wont... if the cars pull more than 8amps at the rails and the APB will shut down into safe mode!!!

The APB makes having a bench big PSU pointless...