12 vdc Inductive ignition timing light bulb weak flash?

PackratKing

Joined Jul 13, 2008
847
An inductive timing light, draws its high energy by clamping onto #1 spark-plug cable... There are 2 varieties of timing light,,, one has a neon bulb [ useless ] the other a Xenon flashtube.
In a photographic strobe, the flashtube is ionized by the trigger circuit, when the shutter contacts close...

The trigger circuit dumps its capacitor through the trigger coil, which ionizes the xenon gas, and in turn dumps the main capacitor through the flashtube...

Xenon timing lights do not have to be as bright as Photoflash, so their firing off the spark-plug high voltage is adequate...
Over time, if you use it a lot... the flashtube may have lost its xenon, so would not be as bright.
 

Thread Starter

sdowney717

Joined Jul 18, 2012
711
Thanks.
Since it has clamps to hook to the battery, and an inductive clamp to go around the spark wire, wont it use the spark wire just as a signal to fire the bulb? Meaning it is not using the spark energy like a neon bulb to flash, this is a xeon bulb. So is it using the 12vdc boosted up to fire the bulb?
 

Thread Starter

sdowney717

Joined Jul 18, 2012
711
It got very little usage.
I have had it for 20 years and I used it at most 20 times.
I suppose I will take it apart and see how it was made.
I was thinking to time the boat engine easily, but go to use it and it is hard.
So I will time the engine statically. Engine has a pertronix ignitor.
So line up the timing marks and rotor to #1 cylinder and twist distributor till it sparks is basically what you do. Or you could put a meter or 12vdc bulb on the distributor to coil wires, positive on 12vdc+, negative on distributor to coil wire.
Since ignition coil fires with collapsing mag field, when ground turns off after ground turns on, coil fires.
 
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shortbus

Joined Sep 30, 2009
10,045
I've also had mine about that time and used it even less. Can't even see a spark plug on my present car to see if the strobe still works :D.
If the car is newer than ~2000 model the timing light wouldn't help any way. All of the timing is done in the ECU. Cam and crank sensors set the timing now.
 

debe

Joined Sep 21, 2010
1,389
This is a capacitance pickup one that's at least 30 yrs old & still works fine. The operating principals will be the same. There has to be an inverter to convert the 12V to HV, & a trigger circuit. The dump capacitor on this one stores a bout 650V dc, this is what I would check first.TIMING LIGHT.1.JPG TIMING LIGHT.2.JPG TIMING LIGHT.9.JPG TIMING LIGHT.11.JPG
 
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Thread Starter

sdowney717

Joined Jul 18, 2012
711
Here is mine, how are you checking the volts?
Hook up to battery and measure across the yellow capacitor?
Mine has no numbers on it. What values should it have for capacitance and volts?
 

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ian field

Joined Oct 27, 2012
6,536
Here is mine, how are you checking the volts?
Hook up to battery and measure across the yellow capacitor?
Mine has no numbers on it. What values should it have for capacitance and volts?
The inverter voltage should be present across the yellow capacitor whenever the xenon isn't triggered.

The components frequently have no markings - the circuit isn't hard to copy, and those already selling them don't want more people making them.

The value marked on the photo posted earlier are pretty much typical.
 

Thread Starter

sdowney717

Joined Jul 18, 2012
711
Thanks, what is 2.0K in mfd??
I understand the voltage number.

I connected to a 12v battery charger.When I pull the trigger, voltage across the yellow capacitor is 254volts, which is too low compared to 653 volts?.
Why would it be low? Is it too low?
 
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Thread Starter

sdowney717

Joined Jul 18, 2012
711
http://comingsoon.radioshack.com/products/findInStore/2721145?zipcode=23608
How about this for a replacement?
I have seen polarized +- on some bulbs, would hooking it backwards destroy it?
Think my bulb is marked?

"Because the cathode is more emissive than the anode, the flashtube is polarized, and connecting the lamp to the power source incorrectly will quickly ruin it. "
So I suppose so!
https://en.wikipedia.org/wiki/Flashtube

How can I determine what is + and what is -

Well, examining the current bulb with a lens shows distinctly different internal end appearance, a collar of metal on one end. So maybe matching the bulb construction will work.
 
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bertus

Joined Apr 5, 2008
22,270
Hello,

Is the multimeter still in working order?
I see the battery low indicator in the left corner of the LCD.

Bertus
 

Thread Starter

sdowney717

Joined Jul 18, 2012
711
I pulled off the little wire plugs that attach to the circuit board and reattached them.
Flash seems a little better, so next step is test it again on the motor.
 
I pulled off the little wire plugs that attach to the circuit board and reattached them.
Flash seems a little better, so next step is test it again on the motor.
I have a Sears Inductive timing light as well. Just reverse engineered it as I thought it stopped working but then it hadn't. One component in it I couldn't identify. Let me know if you want it or if it should be displayed.
 

MisterBill2

Joined Jan 23, 2018
18,167
I would examine all of the connections because in portable equipment, especially in seldom used items, the connections deteriorate and develop a higher resistance. In fact, that is so simple to do and fixes enough of the problems that I always do it. Also, check the connections to the flash lamp, because the instant current is quite high, so any resistance will cause a big voltage drop.
 

MisterBill2

Joined Jan 23, 2018
18,167
I have been given a couple of those neon timing lights and I have been wondering if there is some way to flash those tubes, which are much bigger than the xenon flash tubes. And while car ignition systems are no longer easily adjustable, mower engines and leaf blower, and string trimmer engines still can be tweeked a bit. So the timing lights can still be useful.
 
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