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Test Bench. Most of the tests were ran with the drill spinning 450 rpm, and all were tested on a 22r vacuum advance distributor.
This is the signal that i need to mimic.
If you take mode A1 and A2 unmodified from the datasheet, they will return a nice signal for use with higher tooth count trigger wheels. Mode A will almost perfectly space each tooth passing High and Low.
When hooked up in mode B, with Zero_en to 5v and Int_Thresh to Ground, and with Ext disconnected, you get this. It doesn't really matter what voltage you feed bias, it will mostly look like the lower image.
Using the same setup as before, except using a 1000ohm, 20000ohm resistor voltage divider, you get a slightly longer pulse, and also need a slightly larger capacitor between the 2 vr sensor leads. I found that a larger cap is needed as interference (Even from your fingers) can make the readings wander. I still need to find the right size cap to use. I think this setup will work for me, assuming I can find a reliable capacitor size.
If you forget to attach the bias lead to 5v, the graph looks almost identical, except with the output voltage at .5v.
Feel free to add your findings about this chip and it's siblings. I'll update if i keep playing around with it.
Test Bench. Most of the tests were ran with the drill spinning 450 rpm, and all were tested on a 22r vacuum advance distributor.
This is the signal that i need to mimic.
If you take mode A1 and A2 unmodified from the datasheet, they will return a nice signal for use with higher tooth count trigger wheels. Mode A will almost perfectly space each tooth passing High and Low.
When hooked up in mode B, with Zero_en to 5v and Int_Thresh to Ground, and with Ext disconnected, you get this. It doesn't really matter what voltage you feed bias, it will mostly look like the lower image.
Using the same setup as before, except using a 1000ohm, 20000ohm resistor voltage divider, you get a slightly longer pulse, and also need a slightly larger capacitor between the 2 vr sensor leads. I found that a larger cap is needed as interference (Even from your fingers) can make the readings wander. I still need to find the right size cap to use. I think this setup will work for me, assuming I can find a reliable capacitor size.
If you forget to attach the bias lead to 5v, the graph looks almost identical, except with the output voltage at .5v.
Feel free to add your findings about this chip and it's siblings. I'll update if i keep playing around with it.
