Author Topic: How do I modify this strobe light circuit to light when I want it to?  (Read 1671 times)

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Offline ticktock3tTopic starter

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I'm currently working on a project at my university where we are trying to observe the movement droplets. It is a centrifugal microfluidic device that has been glued to a CD and placed on a motor which spins the disc. Unfortunately, it's a cheap motor which doesn't have a steady rpm and it shifts around a lot. To view the droplets we used a standard off the shelf xenon strobe light but because of the unreliable RPM we can't actually see the formation of the droplets. To get around this we took apart the strobe light circuit and are trying to come up with a way to flash the xenon light source every time the disc complete a full rotation. We were thinking about having a metal rod stick out and two brushed wires,connected to the strobe light circuit, lie over the disc and when the rod touches both wires it completes the circuit and trips with xenon light. I'm not exactly sure where to place the wires to do this as the POT controls the speed of the strobe light. I am following this strobe light schematic and trying to compare it to the circuit board I am working with: http://www.xenonflashtubes.com/schematics/

My Strobe Light Circuit Board: http://imgur.com/a/Zrwrn
-The main(large) capacitor is 47uF


 

Offline Seekonk

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Re: How do I modify this strobe light circuit to light when I want it to?
« Reply #1 on: November 29, 2015, 06:56:17 am »
How large is the disk?   I had a machine with a 15 inch metal disk that I drilled a hole in and placed a 1/16 inch neo magnet in that balanced ok.  Pickup was a hall sensor that worked fine at 2,000rpm.  That could also be done with reflective tape and LED pickup.    Then just drive a transistor.  Wire pickup wouldn't  be reliable.
 

Offline oldway

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Re: How do I modify this strobe light circuit to light when I want it to?
« Reply #2 on: November 29, 2015, 08:36:39 am »
I think it would be easier to stabilize the RPM of the motor than to modify the strobe circuit.
Feeding the DC motor with a regulated voltage should help.
I recomand to use a resistor (calculated to have the same current as the motor at full load) in parallel with the motor to obtain better regulation. (act as a 2 quadrants power supply)
 

Online Zero999

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Re: How do I modify this strobe light circuit to light when I want it to?
« Reply #3 on: November 29, 2015, 11:26:59 am »
It's very difficult to stabilise the motor speed without some kind of feedback from the strobe.

It's probably best to buy a strobe with an external trigger. For safety sake there needs to be some form of electrical isolation between the trigger circuit and the strobe.
 


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