Dim Dash Instruments
Discussion
Mr Cerbera said:
Jabbah, any chance of detailing what you did to include a fader for a numpty like me ??
When I bought it the LEDs that were in the standard bulb positions were wired in separately as they weren't the right type. I haven't checked but I expect they are just patched into the same wires that go to the lights for the oil pressure / water temp / clock / fuel gauges. All I did was add in a 1K pot to the +12v source for the two LED strips and used a couple of cable ties to secure it behind the cowling that holds the clock and fuel gauge. I connected the +12v to one of the outside terminals and the middle one to the LEDs.Used this one:
http://www.maplin.co.uk/p/omeg-1k-andohm-linear-si...
Jabbah said:
When I bought it the LEDs that were in the standard bulb positions were wired in separately as they weren't the right type. I haven't checked but I expect they are just patched into the same wires that go to the lights for the oil pressure / water temp / clock / fuel gauges. All I did was add in a 1K pot to the +12v source for the two LED strips and used a couple of cable ties to secure it behind the cowling that holds the clock and fuel gauge. I connected the +12v to one of the outside terminals and the middle one to the LEDs.
Used this one:
http://www.maplin.co.uk/p/omeg-1k-andohm-linear-si...
You are a Star !Used this one:
http://www.maplin.co.uk/p/omeg-1k-andohm-linear-si...
What did you use for a knob ?? (Titter)
Boba F.
Very nice - my Cerb dials are lit with glow worms so its great to see what can be done inside the dials. Likewise this job is now on the to-do list. Many thanks.
All a bit dependent on exactly how you've implemented it but having an electronic background and wanting to do this now I had thoughts:
If you want a dimmer you could use a LM317 voltage regulator which even though its a sledge hammer to crack a nut has three advantages.
(A) if the battery voltage goes up and down the dash lighting is steady as a rock.
(B) if there is a short circuit in the dials the regulator will shut down when it gets too hot - so if your LED strip blows it won't melt the dash or blow the fuse, hopefully. Also put an electronically resettable fuse in line.
This one is 500mA - select according to your normal current draw plus a bit
http://www.rapidonline.com/electrical-power/rayche...
(C) the voltage (dimmer) control on the regulator is low current.
It's a bit easy to overheat low value potentiometers if your passing a highish current through them because while they may say they are 1W this is 1W spread across the track rather than 1W over the last 5% of the track. If it gets damp it may be an unhappy bunny. Whereas something like http://www.rapidonline.com/electronic-components/s... coupled with a regulator will be nice and reliable... I hope.
This LM317 flavour is 1.5A so at the current probably won't need a heat-sink unless you really like your dashboard like Blackpool.
http://www.rapidonline.com/electronic-components/s...
As a daft aside I was wondering about http://www.rapidonline.com/electronic-components/l... plus a transistor, opamp and other guff so it is controlled by the ambient light but perhaps on reflection that's overkill or in fact unwanted.
I found LED strips at Rapid too http://www.rapidonline.com/electronic-components/t... I would presume that inside the dials IP65 grade waterproofing was not needed. Anyone please advise me if you know different.
Anyhow all that said - very nice job, I shall be copying you shortly.
Wurgle
All a bit dependent on exactly how you've implemented it but having an electronic background and wanting to do this now I had thoughts:
If you want a dimmer you could use a LM317 voltage regulator which even though its a sledge hammer to crack a nut has three advantages.
(A) if the battery voltage goes up and down the dash lighting is steady as a rock.
(B) if there is a short circuit in the dials the regulator will shut down when it gets too hot - so if your LED strip blows it won't melt the dash or blow the fuse, hopefully. Also put an electronically resettable fuse in line.
This one is 500mA - select according to your normal current draw plus a bit
http://www.rapidonline.com/electrical-power/rayche...
(C) the voltage (dimmer) control on the regulator is low current.
It's a bit easy to overheat low value potentiometers if your passing a highish current through them because while they may say they are 1W this is 1W spread across the track rather than 1W over the last 5% of the track. If it gets damp it may be an unhappy bunny. Whereas something like http://www.rapidonline.com/electronic-components/s... coupled with a regulator will be nice and reliable... I hope.
This LM317 flavour is 1.5A so at the current probably won't need a heat-sink unless you really like your dashboard like Blackpool.
http://www.rapidonline.com/electronic-components/s...
As a daft aside I was wondering about http://www.rapidonline.com/electronic-components/l... plus a transistor, opamp and other guff so it is controlled by the ambient light but perhaps on reflection that's overkill or in fact unwanted.
I found LED strips at Rapid too http://www.rapidonline.com/electronic-components/t... I would presume that inside the dials IP65 grade waterproofing was not needed. Anyone please advise me if you know different.
Anyhow all that said - very nice job, I shall be copying you shortly.
Wurgle
Think personally I would go pulse width, more complexity but its the best way to drive LEDs, eliminates wavelength shift and well designed is efficient on heat!
I'm currently (See what I did there?) building a tri colour dashboard using PWM so you could have any colour you want, little way off as theres a gazillion other things I need to do, but watch this space!
Funny you should mention rapid, as they are my local electronics shop!
I'm currently (See what I did there?) building a tri colour dashboard using PWM so you could have any colour you want, little way off as theres a gazillion other things I need to do, but watch this space!
Funny you should mention rapid, as they are my local electronics shop!
Interesting... I thought LM317 because its easy to make and the power is lowish so the waste heat is not too bad. My only worry if you feed the LEDs with an unfiltered PWM switching waveform is radiated interference from the long LED wires (read antenna). How about PWM using an Arduino Nano and 3 logic level FETs for R-G-B. You could have all sorts of stuff using other inputs e.g. dash goes red shift light. You name it. The code would be dead easy.
https://www.arduino.cc/en/Main/ArduinoBoardNano
http://uk.farnell.com/vishay-semiconductor/irld024...
Being such an old f**t I was thinking of warm white LEDs as they are quite easy on the eyes. A soft orange-amber as used for many aircraft at night as this part of the spectrum causes the eyes to react to light levels less so if you look at the instruments you can see them OK but then when you look back at the road you can still see it, not a bunch of spots. Its bad on unlit country lanes the white electroluminescent display of my family car gets dimmed right down.
Perhaps this calls for an RGB experiment with an old bedside clock stuck to my dashboard.
BTW – are you also replacing the LEDs that light the indicators, MIL, main beam etc.? On mine the indicator is almost invisible if the sun is shining from behind.
https://www.arduino.cc/en/Main/ArduinoBoardNano
http://uk.farnell.com/vishay-semiconductor/irld024...
Being such an old f**t I was thinking of warm white LEDs as they are quite easy on the eyes. A soft orange-amber as used for many aircraft at night as this part of the spectrum causes the eyes to react to light levels less so if you look at the instruments you can see them OK but then when you look back at the road you can still see it, not a bunch of spots. Its bad on unlit country lanes the white electroluminescent display of my family car gets dimmed right down.
Perhaps this calls for an RGB experiment with an old bedside clock stuck to my dashboard.
BTW – are you also replacing the LEDs that light the indicators, MIL, main beam etc.? On mine the indicator is almost invisible if the sun is shining from behind.
Thats actually a good idea.
In fact I think I might work on that, I like the idea of having a progressive change in the latter rev ranges for gear change, or perhaps have them start blinking flashing alternately or anything really.
I also tend to agree with the colour, blue and/or bright white can be very in your face especially at night, but going RGB woudl mean you could have Blue daytime running, then amber for night. Possibilities are endless.
Hmm, like it....
In fact I think I might work on that, I like the idea of having a progressive change in the latter rev ranges for gear change, or perhaps have them start blinking flashing alternately or anything really.
I also tend to agree with the colour, blue and/or bright white can be very in your face especially at night, but going RGB woudl mean you could have Blue daytime running, then amber for night. Possibilities are endless.
Hmm, like it....
Edited by tofts on Sunday 21st February 11:46
Gassing Station | Cerbera | Top of Page | What's New | My Stuff