home made Timing light

[georgesgiralt]

Hello !
Some time ago we discussed timing lights for our beloved engines.
I own one (see http://www.aliexpress.com/item/DIGITAL-DISPLAY-GOOD-QUALITY-PROFESSIONAL-TIMING-LIGHT-TOOLS-INDUCTION-DIGITAL-DISPLAY-TIMING-LIGHT-TESTING-TOOLSWT04823/688720439.html?spm=2114.01010208.3.25.t5DxRz&ws_ab_test=searchweb201556_0,searchweb201602_3_10037_10017_405_404_407_406_10032_10040,searchweb201603_2&btsid=a927d011-94f0-4554-8011-181110d02997  )
which includes a micro-processor to alter the timing advance and measure the RPM. Alas, the high voltage power converter is fried. All my attempts to make it work were useless. So I searched for an alternative to the Xenon light and found this : http://a110a.free.fr/SPIP172/article.php3?id_article=145
It is a design using an Arduino board and a bright white LED to make a timing light.
As my micro controler part is still working, I'll use it instead of buying a mini duino board or using my Arduino board.
I'll also re-use the pick-up coil and some optocoupler to avoid putting high spikes on the micro controller board.

I'll try to power the timing light from a 3.7 Li ion  battery I own instead of the R65 12 V battery to make the device more usable. If this work, I'll have to make 5V from the 3.7V and add the charging and protection circuitry for the battery.
And I intent to reuse the red Chinese case for the whole because the case is always the difficult part.  

As some of you may be interested, I would like to know if you will intent to build one ? And if yes with what kind of specifications ?

If there is some interest I'll document my progress and show you how get the parts along the route. Otherwise, I'll do it my way in my garage and keep my findings for me ;-)
What do you think ?

[skippyc]

I love home made items and am in the process of looking for a timing light.
Just  to add I looked at a timing light with taco and it said not for use on 2 strokes, so I realized a BMW ignition is technically a 2 stroke

[georgesgiralt]

Well, it actually can. Nothing tells the timing light to what engine it is connected.
The limitation comes from :
what is the max RPM the light can synchronize with
is the RPM indicated accurate

The RPM calculation will be off by a factor of 2 because the BMW fire once per revolution as a traditional 4 stroke only fire once per TWO revolution... You do the math ;-)

The most annoying is the maximal RPM for the light. If you can't have a spot when the engine is at 3500 RPM to check for maximal advance the stuff is of a lesser use. (in the software the advance calculation is done based on one strobe per TWO revolutions but you won't see this your eyes are not fast enough)

The advantage of a software timing light is that you can change the software to suit you big two stroke ;-)

For now it will be an assembly job because I've found the needed components :
Turning the 3.7V into 5V for the whole :
http://www.aliexpress.com/item/0-9V-5V-to-5V-DC-DC-Voltage-Converter-Step-Up-Booster-Module/32332755373.html?spm=2114.10010108.1000023.2.s4dh9I
Keeping care of the Li-Ion battery and charging it :
http://www.aliexpress.com/item/1pcs-5V-1A-Micro-USB-18650-Lithium-Battery-Charging-Board-Charger-Module-Protection-Dual-Functions/32469933999.html?spm=2114.01010208.3.51.qBfErl&ws_ab_test=searchweb201556_0,searchweb201602_3_10037_10017_405_404_407_406_10032_10040,searchweb201603_2&btsid=41bb9ca9-6508-4f76-9548-e6ea30d4acd8
then we need a high power LED with embedded commanding transistor :
http://www.ebay.com/itm/3W-High-Power-KEYES-LED-Module-with-PCB-Chassis-for-Arduino-STM32-AVR-/311422238536?rmvSB=true

[Tony Smith]

I love home made items and am in the process of looking for a timing light.
Just  to add I looked at a timing light with taco and it said not for use on 2 strokes, so I realized a BMW ignition is technically a 2 stroke

Not Really :-)

But it does fire a waste spark, an endeavor it is hardly alone in. Most Japanese 4cyl bikes have only two coils and all sixes I've looked at have only three. A waste spark is inherent in them.