[Tassem]

Excellent work! I love it when DIY overtakes OEM. What plans next?

I've bought a pack of self blinking Red LEDS from ebay. I want to rig one up in such a way that it works only when the car is switched off. (Theft Deterrent)

Could you share some circuit ideas please?

[ZBlue]

Originally Posted by Tassem

Excellent work! I love it when DIY overtakes OEM. What plans next?

I've bought a pack of self blinking Red LEDS from ebay. I want to rig one up in such a way that it works only when the car is switched off. (Theft Deterrent)

Could you share some circuit ideas please?

You want just the LED as a visual theft deterrent ? Where do you plan to install it ?

In any case , the more elegant solution to what you plan to do would involve a relay. The relay would need to be triggered by two conditions - the doors are locked and the key is out of the ignition.

A simpler solution would be to just use a switch and manually switch the LED on/off as required. In both cases you would draw power from an always-on source in the fuse box , or directly from the battery with an appropriate fuse.

PS - This is based on my very limited knowledge of car electricals. I hope somebody more in the know will chime in

[Tassem]

The car comes with an immobiliser. I just like to see a slow flashing led, plus its a visual deterrent.

Don't want the switch method. Too crude

However, I remember using a simple circuit which works like a relay when there is no voltage detected at a particular terminal. My plan is to tap into the ignition for that signal. The power for the led being direct from the battery. ( not a hard wire, but again a tap from an always on source.) This way when the ignition is turned off, the switch detects no voltage and turns on the led.

*EDIT - It was a relay. However, contrary to the usual ones, this relay works in the absence of voltage across a particular terminal.

Does that make sense? I just wish I cud remember what it was called or how it was done.

Originally Posted by ZBlue

You want just the LED as a visual theft deterrent ? Where do you plan to install it ?

In any case , the more elegant solution to what you plan to do would involve a relay. The relay would need to be triggered by two conditions - the doors are locked and the key is out of the ignition.

A simpler solution would be to just use a switch and manually switch the LED on/off as required. In both cases you would draw power from an always-on source in the fuse box , or directly from the battery with an appropriate fuse.

PS - This is based on my very limited knowledge of car electricals. I hope somebody more in the know will chime in

[ZBlue]

Originally Posted by Tassem

The car comes with an immobiliser. I just like to see a slow flashing led, plus its a visual deterrent.

Don't want the switch method. Too crude

However, I remember using a simple circuit which works like a relay when there is no voltage detected at a particular terminal. My plan is to tap into the ignition for that signal. The power for the led being direct from the battery. ( not a hard wire, but again a tap from an always on source.) This way when the ignition is turned off, the switch detects no voltage and turns on the led.

*EDIT - It was a relay. However, contrary to the usual ones, this relay works in the absence of voltage across a particular terminal.

Does that make sense? I just wish I cud remember what it was called or how it was done.

You might find something useful here :

http://www.the12volt.com/relays/relays.asp

[Tassem]

Thanks for that. I just remembered - Its called a Normally Closed Relay! Time to get into DIY mode!

Looking forward to more of your work!

Originally Posted by ZBlue

You might find something useful here :

http://www.the12volt.com/relays/relays.asp

[ZBlue]

As the title suggests , this is a failed DIY - read ahead at you own risk

Having done the interior lights and spoiler brake lights with LED's , I decided to convert the boot lights as well , but using DIY PCB's. The DIY kit was purchased from EBay. Theoretically , the basic steps involved in etching a PCB are :

• Create the board layout using a PCB software . I used PCB Wizard. Various other software are also available e.g. ExpressPCB , Fritzing (Multi-platform)
• Transfer the layout using a laser printer to Toner Transfer Paper/Photo Paper and iron onto copper clad board
• Etch the board using Ferric Chloride or other etchant
• Remove toner using acetone

The kit available on EBay is pretty self-sufficient and includes most components you would need to make a PCB. The only other things required are a laser printer (inkjet will not work) and familiarity with a PCB design software.

The intended board was to have a simple 3x3 LED array , resistors and a voltage regulator. This is what the output looks like , printed on Toner Transfer Paper (comes with the kit).



Also featured is the 5cmx4cm copper board

Took me the better part of the afternoon to get the layout correct - component placement , printing at 100% , making sure all edges line up , trace width , hole sizes etc.. anyways , moving on

Here is the design ironed onto the board.



Red flag I failed to notice - some of the holes already looked warped. The toner probably got smudged due to too high a temperature during ironing and further smeared by incorrect rubbing. The difference from the design on paper is evident. There everything is sharp and all edges are well-defined.

After this the board was etched using a Ferric Chloride solution. The packet of etchant was wrapped in around 10 layers by the seller , and for good reason too. It stains everything it comes in contact with and should be handled carefully.

To etch the board , you can either just put it in the solution and move it around. Alternatively , you can take a sponge , dip it in the etchant and rub away lightly on the copper. i used the second method and it was surprisingly fast. Took me about the 4-5 minutes to get all the copper off. It is suggested that you leave as much copper on the board as possible. While this may consume more toner while printing , it significantly reduces the etching time. The resultant board with holes drilled with a 1mm bit and a dremel :



No go ! A pre-requisite of drilling the holes accurately is that the transfer should be fairly precise so that the holes have well-defined centers. The centers are obviously etched leaving you with a dimple surrounded by copper. The dimple acts as a guide for the drill bit. Since the holes I got were warped , the drill bit wandered all over the place and actually stripped some copper for some of the holes. On the brighter side , the component placement/sizes were spot on.

I will just call this Board Rev. V1 and take another attempt in the coming weekends !

[ZBlue]

Finally managed to get the PCB and the boot lights done . Some pictures :

[mathuranuj]

Originally Posted by ghpk

Nice D.I.Y.
Certainly Looks very Bright.
I used these Pirhana L.E.D.'s Earlier for Dome, but Moved to 1 Watt ones which need Star shaped Base which works as Heat Sink, These L.E.D. are too Bright and Just two of them Light up Santro's Front part of cabin very well.

Pic is of Un-soldered L.E.D. to its base.
Attachment 1089883

Can you please post or PM details for "brake light flasher - quick strobes followed by steady light , 15 second reactivation delay."

Hi

Can you please tell me where you bought these LEDs. I have been looking for these since ages and don't know where to find them. Also, if you can give an estimate of the cost. Thanks!

[blackwasp]

Great DIY, and a neat setup for work as well. I've been wanting to do a similar DIY since a while now. Have all the tools with me and this reminds me of my engineering days. Soldering projects late into the night with music blasting and the satisfaction of seeing it working in the morning in front of Judges/examiners.

A small query. A friend and I tried such a DIY of VW car and she started throwing up errors in mid. I currently have an abarth so what are the current and voltage levels I should stick to ?

[ghpk]

Originally Posted by mathuranuj

Hi

Can you please tell me where you bought these LEDs. I have been looking for these since ages and don't know where to find them. Also, if you can give an estimate of the cost. Thanks!

They are very easy to get in any electronics parts store.
they are like Rs.1.5 each for 1 watt L.E.D and Rs.1 for each base but this was bulk pricing for a couple of them I am sure you won't even mind paying shop keeper the double price as they are mostly kept with packs of 500 or 1000.

If I remember correctly they are working fine in car since last 2-3 years, I am using 2 of them and one resistor.

[abhi_tjet]

Originally Posted by ZBlue

Finally managed to get the PCB and the boot lights done . Some pictures :

Hi Zblue, I am planning a DIY of upgrading the central roof lights of my Linea to led. Can you please confirm its 'taking out' mechanism? Can I just pry it to pop open? There is a black rubber border surrounding the dome light. Any significance of this? Something to take care?

[ZBlue]

Originally Posted by abhi_tjet

Hi Zblue, I am planning a DIY of upgrading the central roof lights of my Linea to led. Can you please confirm its 'taking out' mechanism? Can I just pry it to pop open? There is a black rubber border surrounding the dome light. Any significance of this? Something to take care?

Yeah you can just pry it out from the sides with a flat-head screwdriver.

[abhi_tjet]

Originally Posted by ZBlue

Yeah you can just pry it out from the sides with a flat-head screwdriver.

Thanks Zblue. Can you confirm about any specific type of led's which can be put in registration lights. I tried quite a few and all of them threw the error in MID.