Appropriate switch for a 555 LED strobe?

[eester B]

I would like it to activate a strobe light in unison with the speed of my bicycle: 10 flashes per rotation of my 26" bicycle tire. This will be ~30 Hz at full speed.

My circuit uses a one-shot 555 timer and 2x 1W LEDs (3.5V each, 350 mA), runs on 12V. Now I need a switch. My intention is to attach 10 magnets/emitters to the outer rim of the wheel, and the sensor to the front fork.

I have fiddled with a couple reed switches I found in the store but there is no way that they will be able to detect up to 30 shots per second, I also understand they are sensitive to vibration?
I'm not sure about optosensors as there is nowhere I can buy them where I live, and I need explanations the likes of which mouser and the like cannot provide.

What switch or sensor can I use for this application?

Thank you *so* much for any help,

EB

 

[mister_rf]

You may use a Hall-Effect Digital Position Sensor, Mouser code:

785-SR13C-A1

**broken link removed**

 

[eester B]

You may use a Hall-Effect Digital Position Sensor, Mouser code:

785-SR13C-A1

https://sensing.honeywell.com/product page?pr_id=36384

Thanks!

I am unclear how to make the hall effect sensor trigger the 555 timer now.
Output of the sensor goes low when triggered, but the 555 trigger wants high?
So, do I connect the output of the sensor to the base of a PNP transistor (and transistor collector to (-) and emitter to 555)? Which transistor/how do I know which transistor?

I previously faked it somehow by connecting the sensor output to the 555 trigger pin, as well as to (+) through a 500K resistor. It worked for a bit but I think it fried either the sensor or the timer.

Thanks for any help you can give.

EB