PopRivet

Well-Known Member
Today, I did something about the car’s clock. It was a bone-of-contention because although it worked well enough to show the time the back-light proved to be very poor. The story of what I did to improve it follows. Oh, the soldering isn’t my best, but the quality of solder I have is not very good. I’ll need to get some more before I try soldering again. Ebay as per usual.

I checked out the bulb, which was working perfectly, but its wattage was questionable. The bulb was moulded into a plastic holder and not one of the types where a replacement could be fitted into. I was met with a quandary. I could refit it and put up with an almost none-existent back-light… or rip into it to modify. I ripped into it! I love a challenge.
DSCF0300.JPG

To cut a long story short, I initially tried a 5mm & 10mm RED Led - separately, but with a GREEN lens between the LED light & display they were singularly no good.


I then fitted a 10mm WHITE LED, and it proved to be very good. However, an LED light doesn'tDSCF0308.JPG spread as well as a conventional filament-bulb, so the illumination tended to be centralised.

That’s when I fitted two 5mm WHITE LED’s as well, one on each side of the 10mm.
DSCF0311.JPG
I should have taken more photos, but here's a clock on Ebay, showing just how dim they can be.
Clock - dim on Ebay.jpg

That did the trick.

So my recipe for getting a brighter CLOCKFACE is, one 10mm LED & two 5mm LED’s - all white. Each LED required a 520 Ω, ¼ watt resistor. I guess a single ½ watt would suffice, with all LED’s fitted in parallel.
DSCF0313.JPG

I used my soldering iron to cut/melt the holes as required, with some existing internal burr creating some shade. I’ll break into the clock another day to finish that off. However, I’m pleased with the result and the back-light still dims when the headlights are switched on too.
 
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Today, I did something about the car’s clock. It was a bone-of-contention because although it worked well enough to show the time the back-light proved to be very poor. The story of what I did to improve it follows. Oh, the soldering isn’t my best, but the quality of solder I have is not very good. I’ll need to get some more before I try soldering again. Ebay as per usual.

I checked out the bulb, which was working perfectly, but its wattage was questionable. The bulb was moulded into a plastic holder and not one of the types where a replacement could be fitted into. I was met with a quandary. I could refit it and put up with an almost none-existent back-light… or rip into it to modify. I ripped into it! I love a challenge.
View attachment 135760

To cut a long story short, I initially tried a 5mm & 10mm RED Led - separately, but with a GREEN lens between the LED light & display they were singularly no good.


I then fitted a 10mm WHITE LED, and it proved to be very good. However, an LED light doesn'tView attachment 135761 spread as well as a conventional filament-bulb, so the illumination tended to be centralised.

That’s when I fitted two 5mm WHITE LED’s as well, one on each side of the 10mm.
View attachment 135762
I should have taken more photos, but here's a clock on Ebay, showing just how dim they can be.
View attachment 135768

That did the trick.

So my recipe for getting a brighter CLOCKFACE is, one 10mm LED & two 5mm LED’s - all white. Each LED required a 520 Ω, ¼ watt resistor. I guess a single ½ watt would suffice, with all LED’s fitted in parallel.
View attachment 135763

I used my soldering iron to cut/melt the holes as required, with some existing internal burr creating some shade. I’ll break into the clock another day to finish that off. However, I’m pleased with the result and the back-light still dims when the headlights are switched on too.
Nice one Pop, the replacement bulbs are 5 or 6 quid so a few pence on led's and a bit of time makes sense to me.
 
Nice one Pop, the replacement bulbs are 5 or 6 quid so a few pence on led's and a bit of time makes sense to me.
It's such an easy thing to do, if you are okay with electronics. If anyone needs any advice I'm only too happy to help. And the best thing is, as Alibro knows, LED's are cheap, efficient, and extremely long-lasting. The things I could do to a car! Wanted... Machine guns. Lol.
 
Today, I did something about the car’s clock. It was a bone-of-contention because although it worked well enough to show the time the back-light proved to be very poor. The story of what I did to improve it follows. Oh, the soldering isn’t my best, but the quality of solder I have is not very good. I’ll need to get some more before I try soldering again. Ebay as per usual.

I checked out the bulb, which was working perfectly, but its wattage was questionable. The bulb was moulded into a plastic holder and not one of the types where a replacement could be fitted into. I was met with a quandary. I could refit it and put up with an almost none-existent back-light… or rip into it to modify. I ripped into it! I love a challenge.
View attachment 135760

To cut a long story short, I initially tried a 5mm & 10mm RED Led - separately, but with a GREEN lens between the LED light & display they were singularly no good.


I then fitted a 10mm WHITE LED, and it proved to be very good. However, an LED light doesn'tView attachment 135761 spread as well as a conventional filament-bulb, so the illumination tended to be centralised.

That’s when I fitted two 5mm WHITE LED’s as well, one on each side of the 10mm.
View attachment 135762
I should have taken more photos, but here's a clock on Ebay, showing just how dim they can be.
View attachment 135768

That did the trick.

So my recipe for getting a brighter CLOCKFACE is, one 10mm LED & two 5mm LED’s - all white. Each LED required a 520 Ω, ¼ watt resistor. I guess a single ½ watt would suffice, with all LED’s fitted in parallel.
View attachment 135763

I used my soldering iron to cut/melt the holes as required, with some existing internal burr creating some shade. I’ll break into the clock another day to finish that off. However, I’m pleased with the result and the back-light still dims when the headlights are switched on too.

Your LEDs are currently being driven at at just over 20 mA, which is split between the 3 if there wired in parallel with just one resistor. If each LED has its own resistor, the each LED is running at 20mA , which is over 100% of its maximum rating. Most standard package white LEDs are designed to run at max of 20mA max, if life is expected to be long. Reducing LED current to 50%, ie 10mA will increase life massively and won't adversely affect light output.
To reduce LED current to under 15mA, run all the LEDs in parallel from 2 series connected 470 Ohm 1/4 watt resistors. I would use the 2 470 Ohm 1/4 watt resistors to spread the dissipation, which is over 200mW in this circuit.
There's little point in using LEDs and resistors, if life is little different to the normal bulb that's fitted. ;)
 
Your LEDs are currently being driven at at just over 20 mA, which is split between the 3 if there wired in parallel with just one resistor. If each LED has its own resistor, the each LED is running at 20mA , which is over 100% of its maximum rating. Most standard package white LEDs are designed to run at max of 20mA max, if life is expected to be long. Reducing LED current to 50%, ie 10mA will increase life massively and won't adversely affect light output.
To reduce LED current to under 15mA, run all the LEDs in parallel from 2 series connected 470 Ohm 1/4 watt resistors. I would use the 2 470 Ohm 1/4 watt resistors to spread the dissipation, which is over 200mW in this circuit.
There's little point in using LEDs and resistors, if life is little different to the normal bulb that's fitted. ;)
Because, Nodge, the illumination of the clock was rubbish, to the point where neither my wife or I could read it during the day - especially when the sun was shining, which is quite common here in Spain. And now we can see it clearly. And if any or all of the LED's or resistors fail it's an easy procedure to replace them. LED's are more efficient, cheaper and I prefer them. In point of fact, LED's are taking over from the old-fashioned, heat generating filament bulbs... and for good reason.
We're just back from a shopping trip and my wife thinks my mod is brillaint. So smarty points for me there. lol
 
Because, Nodge, the illumination of the clock was rubbish, to the point where neither my wife or I could read it during the day - especially when the sun was shining, which is quite common here in Spain. And now we can see it clearly. And if any or all of the LED's or resistors fail it's an easy procedure to replace them. LED's are more efficient, cheaper and I prefer them. In point of fact, LED's are taking over from the old-fashioned, heat generating filament bulbs... and for good reason.
We're just back from a shopping trip and my wife thinks my mod is brillaint. So smarty points for me there. lol
I love the idea and agree with both of you. I agree with Nodge that the components may not last long but it is a simple matter to change the resistors for higher value if it pops.

Pun intended. :p

Edit I just found this but as the voltage will be approx 13.4V with the engine running then a 1k resistor would be better.

How to Calculate Resistor Value for LED Lighting
August 19, 2012 George 0 Comment


Following these steps will give us the resistor value for LEDs powered by 12V, DC:

  1. Determine the voltage and current needed for your LED.
  2. We’ll use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current.
  3. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/.010=860 ohms.
  4. To use several LEDs in parallel, sum the current values. From the example above, if we use 5 white LEDs the current requirement is 10mA x 5 = 50mA. So (12-3.4)/.050=172 ohms.
 
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Whilst I appreciate the effort that you have gone to here poprivet - and your brighter clock does look good, I have to say that I have never had an issue with the clock illumination on mine, even on the brightest of sunny days.
 
Whilst I appreciate the effort that you have gone to here poprivet - and your brighter clock does look good, I have to say that I have never had an issue with the clock illumination on mine, even on the brightest of sunny days.

I've never had a problem reading mine either. Being that it's actually an backlit LCD, it's perfectly visible in bright daylight. Actually lighting a backlit LCD very strongly from behind, will tend to "washout" the display. Being an LCD, it's also visible when the ignition is off, when the backlight would be off.
 
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