Dimming headcode lighting with Loksound V4

[young37215]

Apologies if this has been asked before but I cannot find a thread. I want to dim the intensity of the headcode lights on my diesel fleet using the V4 decoder. Looking in the rather challenging Loksound manual for guidance, on P45 I think it references CV262 with a range of 0 -31.  

 

I have a Guagemaster Prodigy 2 to make CV changes but I am inexperienced in changing CV's. Before I make a complete horlicks of my expensive sound chip, please can someone advise/guide me on the following:

 

is CV262 the correct to CV to change for headcode lighting? If no, what is the correct CV?

what is the typical/factory default setting for headcode light intensity?

what CV setting would result in a more prototypical level of light?

Is the headcode lighting CV any different for a V3.5 decoder?

 

All guidance gratefully received

 

Rob

 

 

[wiggy1]

Apologies if this has been asked before but I cannot find a thread. I want to dim the intensity of the headcode lights on my diesel fleet using the V4 decoder. Looking in the rather challenging Loksound manual for guidance, on P45 I think it references CV262 with a range of 0 -31.  

 

I have a Guagemaster Prodigy 2 to make CV changes but I am inexperienced in changing CV's. Before I make a complete horlicks of my expensive sound chip, please can someone advise/guide me on the following:

 

is CV262 the correct to CV to change for headcode lighting? If no, what is the correct CV?

what is the typical/factory default setting for headcode light intensity?

what CV setting would result in a more prototypical level of light?

Is the headcode lighting CV any different for a V3.5 decoder?

 

All guidance gratefully received

 

Rob

 

Hi Rob,

Yes you need CV 31=16, CV 32=0 before you change the lights.

CV 262 1-31 will change the brightness but unless the head code box lights are on a separate function button which I think are not it will change the brightness of the side lights as well and maybe the head light if fitted.

Not sure of the factory default without putting it on a programmer and down loading the settings.

Set the brightness to your liking, no set figure.

Not sure on the 3.5 decoder but they mostly have the same settings but would have to check.

Any problems just sent me a PM.

Wiggy.

[tractor_37260]

 

Is the headcode lighting CV any different for a V3.5 decoder?

 

All guidance gratefully received

 

Rob

 

 

Yes - and provided the wiring has been altered to make the marker/headlights separate from the tail lights using the Aux 1 & 2 function outputs, it's then possible to dim all 4 lighting circuits independently, using 4 CV's.

[young37215]

Hi Rob,

Yes you need CV 31=16, CV 32=0 before you change the lights.

CV 262 1-31 will change the brightness but unless the head code box lights are on a separate function button which I think are not it will change the brightness of the side lights as well and maybe the head light if fitted.

Not sure of the factory default without putting it on a programmer and down loading the settings.

Set the brightness to your liking, no set figure.

Not sure on the 3.5 decoder but they mostly have the same settings but would have to check.

Any problems just sent me a PM.

Wiggy.

Hi Wiggy

 

Most helpful, thank you. Without the guidance on CV's 31 and 32 my efforts would have come to nought, with your guidance I have now managed to reduce the intensity of the headcode lights in my V4 chipped locos. 

 

However, the proverbial 'but', this does not work on V3.5 chipped locos with Bachmann factory fitted sound. I do not have a manual for V3.5 and have not yet managed to find anything from ESU http://www.esu.eu/en/downloads/instruction-manuals/former-products/ ; can you or anyone else advise the CV adjustments required to vary the headcode lights? 

 

regards Rob

[leopardml2341]

(How) Does that work for LED lamps please?

[young37215]

Page 92 of the ESU manual http://www.esu.eu/en/downloads/instruction-manuals/former-products/

refers to CV113 for Headlight configuration. Last entry shows a range of 0 (dark) to 15 (bright) for the headlight which implies that if I adjust the setting downwards against CV113 I should achieve my aim. please can someone confirm my rationale or correct my misunderstanding

 

Thanks

 

Rob

[wiggy1]

(How) Does that work for LED lamps please?

 

It should work the same as as far as I know all you are doing is reducing the voltage.

Try it and see you can't brake anything.

Wiggy.

[wiggy1]

Page 92 of the ESU manual http://www.esu.eu/en/downloads/instruction-manuals/former-products/

refers to CV113 for Headlight configuration. Last entry shows a range of 0 (dark) to 15 (bright) for the headlight which implies that if I adjust the setting downwards against CV113 I should achieve my aim. please can someone confirm my rationale or correct my misunderstanding

 

Thanks

 

Rob

Yes according to the programmer for 3.5 CV113=1-15 is front light brightness.

Wiggy.

[young37215]

Yes according to the programmer for 3.5 CV113=1-15 is front light brightness.

Wiggy.

Despite what the manual says, changing cv113 has no effect on the headcode lights brightness. Frustrating, I wonder if there are other CV settings that I should have adjusted such as CV31 and 32 with the V4 chip.

 

As ever all counsel gratefully received

 

Rob

[leopardml2341]

Despite what the manual says, changing cv113 has no effect on the headcode lights brightness. Frustrating, I wonder if there are other CV settings that I should have adjusted such as CV31 and 32 with the V4 chip.

 

As ever all counsel gratefully received

 

Rob

Are the lights in question LEDs?

[young37215]

Are the lights in question LEDs?

Good question, I need to take the loco body off to check. The loco is ex 37254, one of the first factory fitted Bachmann sound locos output in banger blue. I am no electrician but if CV 113 reduces voltage, would it not reduce the brightness of the light?   

[leopardml2341]

Good question, I need to take the loco body off to check. The loco is ex 37254, one of the first factory fitted Bachmann sound locos output in banger blue. I am no electrician but if CV 113 reduces voltage, would it not reduce the brightness of the light?

 

No not really.

 

LEDs have a cascade voltage at which they 'switch on' at almost full brightness, there is a small variation in output over the next volt or so but nothing really noticeable. With the body off, you may see some variation for different CV entries, but I'm not hopeful.

 

From the loco you say you're using it is highly likely to be LEDs; some if not most, Heljan locos use small filament bulbs, you might see a noticeable effect on them to prove the theory.

[wiggy1]

Despite what the manual says, changing cv113 has no effect on the headcode lights brightness. Frustrating, I wonder if there are other CV settings that I should have adjusted such as CV31 and 32 with the V4 chip.

 

As ever all counsel gratefully received

 

Rob

 

Not as far as I know 

I don't think the 3.5 is that advanced to be using that many CV's

Try turing the brightness to the lowest setting and see what you get.

Wiggy.

[tractor_37260]

Good question, I need to take the loco body off to check. The loco is ex 37254, one of the first factory fitted Bachmann sound locos output in banger blue. I am no electrician but if CV 113 reduces voltage, would it not reduce the brightness of the light?   

 

Blue 37 254 has LED lighting, and it only has marker and tail lights - no headlights are fitted.

 

Worth bearing in mind on a standard factory Lok V3.5 sound fitted loco, CV 113 controls BOTH the markers at "one" end, and the tail lights at the opposite end together.  CV114 does the reverse.

 

As supplied these CV's are normally set to full brightness = 15 the range being (0-15) Try setting both of them to 0 -  all lights should now be noticeably dimmer, although they can be set anywhere in between 0-15 that suits.

 

Unless you alter the standard wiring circuits, it's not possible to dim the marker lights without dimming the tail lights also at the opposite end.

 

Index CV's 31 and 32 are NOT used on the V3.5 decoder.

 

HTH

 

Ken

 

 

 

.

[leopardml2341]

I really would be interested to know if the brightness of the LEDs can be dimmed - physics says not, but I don't have one to try myself - feedback welcomed.

Rgds

[wiggy1]

I really would be interested to know if the brightness of the LEDs can be dimmed - physics says not, but I don't have one to try myself - feedback welcomed.

Rgds

 

I've just set the dimming on my cab lights from 32-1 and made no difference.

They are LED's factory fitted.

Wiggy.

[young37215]

I've just set the dimming on my cab lights from 32-1 and made no difference.

They are LED's factory fitted.

Wiggy.

I have also tried adjusting CV113 to 0 with no effect. Seems like I am stuck with bright lights on this loco which is not a big deal but would have been nice to sort out.

 

 

Thanks to all for their input and counsel

 

regards Rob

[leopardml2341]

Have you tried physical dimming, e.g. by a piece of thin paper or frosted tape?

[Nigelcliffe]

I really would be interested to know if the brightness of the LEDs can be dimmed - physics says not, but I don't have one to try myself - feedback welcomed.

Rgds

 

All decoders use PWM, so "dimming" doesn't actually reduce the voltage, it reduces the "on time" of a PWM wave.  At low values, the output is mostly off, at high values, fully on.  

 

So, the LED is flickering at high speed, and thus appears dimmer if that flickering has periods of "off" (so long as its not so slow that the flicker is visible).  Use of carefully chosen small capacitors to smooth the flicker can also be used - several RTR model makers do this in their loco wiring.  

 

So, within reasonable limits the decoder outputs can alter the brightness of the LED.  But, more severe changes require the series resistor to the LED to be changed to alter the current available to the LED.

 

Hope that helps explain how dimming if LED lamps works.

 

- Nigel.

[34theletterbetweenB&D]

Theatre lighting gels, coloured sweet wrappers, Pentel felt pens are also excellent, to supplement Andy Sharpe's #18. Enable differential outputs between lights on a common circuit too, and all digitally applied.

[leopardml2341]

All decoders use PWM, so "dimming" doesn't actually reduce the voltage, it reduces the "on time" of a PWM wave.  At low values, the output is mostly off, at high values, fully on.  

 

So, the LED is flickering at high speed, and thus appears dimmer if that flickering has periods of "off" (so long as its not so slow that the flicker is visible).  Use of carefully chosen small capacitors to smooth the flicker can also be used - several RTR model makers do this in their loco wiring.  

 

So, within reasonable limits the decoder outputs can alter the brightness of the LED.  But, more severe changes require the series resistor to the LED to be changed to alter the current available to the LED.

 

Hope that helps explain how dimming if LED lamps works.

 

- Nigel.

 

Thanks Nigel - VERY familiar with PWM as a control mechanism.

 

I didn't know that was how decoders did it on lighting circuits as in this topic (until now) only adjusting 'voltage' (sic) by use of CVs had been mentioned; hence my statement with regard to LEDs and ​voltage. 

[tractor_37260]

 

 

 

I have also tried adjusting CV113 to 0 with no effect. Seems like I am stuck with bright lights on this loco which is not a big deal but would have been nice to sort out.

 

IMG_3104.JPG

 

Thanks to all for their input and counsel

 

regards Rob

 

I've just dimmed all the lights, including cab lights on my own Blue 37 254 with Lok V3.5 using POM - you can visually notice the lighting going dimmer as you reduce the setting down from 15 - most noticeable at 0

 

Although the adjustment can be done on a programming track, using POM instantly shows the changes.

 

Adjusting CV113 will change the brightness at No1 Fan end markers and No2 end tail lights - perhaps your looking for the changes at the wrong end !

 

Like all locos fitted with Lok V3.5's  - all lighting circuits can be dimmed from standard - 37 254 included.

 

 

@ wiggy1 - "I've just set the dimming on my cab lights from 32-1 and made no difference".   

 

Assume this was on a Lok 4 fitted loco ? which CV did you use for that ?  

[Nigelcliffe]

Thanks Nigel - VERY familiar with PWM as a control mechanism.

 

I didn't know that was how decoders did it on lighting circuits as in this topic (until now) only adjusting 'voltage' (sic) by use of CVs had been mentioned; hence my statement with regard to LEDs and ​voltage.

 

There is a lot of loose terminology in model railway control.  Often introduced to explain concepts to people who didn't study electronics and electrical engineering, and whose background knowledge is "variable DC controllers".  So people, including decoder maker instruction sheets, regularly talk of adjusting voltage (be it function output brightness or motor starting level in CV2, etc..), when they are really adjusting the PWM "on time".   

 

If looking at decoders from an electronics engineering perspective, then assume any output - motor or function - is PWM and you'll be right 99% of the time.  Typical at 15kHz-30kHz.

 

 

- Nigel

[young37215]

I've just dimmed all the lights, including cab lights on my own Blue 37 254 with Lok V3.5 using POM - you can visually notice the lighting going dimmer as you reduce the setting down from 15 - most noticeable at 0

 

Although the adjustment can be done on a programming track, using POM instantly shows the changes.

 

Adjusting CV113 will change the brightness at No1 Fan end markers and No2 end tail lights - perhaps your looking for the changes at the wrong end !

 

Like all locos fitted with Lok V3.5's  - all lighting circuits can be dimmed from standard - 37 254 included.

 

 

@ wiggy1 - "I've just set the dimming on my cab lights from 32-1 and made no difference".   

 

Assume this was on a Lok 4 fitted loco ? which CV did you use for that ?  

 

I am delighted to report that having changed CV's 113 & 114 to 0, headcode lights are significantly reduced in brightness. End tail lights are perfectly acceptable at lower levels of brightness meaning 37 191 (ex 254) now blends in with the rest of the fleet which is exactly what I wanted to achieve. I shall post some pictures of 37191 on my Blog when I next get round to an operating session!

 

Thanks to everyone who has contributed for their input.

 

regards Rob

[leopardml2341]

There is a lot of loose terminology in model railway control. Often introduced to explain concepts to people who didn't study electronics and electrical engineering, and whose background knowledge is "variable DC controllers". So people, including decoder maker instruction sheets, regularly talk of adjusting voltage (be it function output brightness or motor starting level in CV2, etc..), when they are really adjusting the PWM "on time".

 

If looking at decoders from an electronics engineering perspective, then assume any output - motor or function - is PWM and you'll be right 99% of the time. Typical at 15kHz-30kHz.

 

 

- Nigel

 

 

I don't have easy access to a 'scope these days; is the modulated fundamental wave, for both motor and aux control, a square or sine? In similarly loose terms, people talk of DCC as being an AC track supply, but of what waveform?