signal converter FROM SINE TO SQUARE WAVE

Use a comparator or high gain amplifier ( squarer ). You need to provide more info if you want more detailed advice.

Graham

if the voltage is high enough ... 5V or more ...but less than 15 ...you could use a 40106 (schmitt trigger).

It is a magnetic sensor which in rightt next to the flywheel maybe 5mm away. Sensor does not require power, it just outputs a signal. That signal is a sinewave. The voltage that I am using is 12V car battery. For my controller to read that signal it needs to be a square wave 0 -

Thank you

Eeyore wrote:

KISS = Keep It Simple, Stupid. A single transistor on the 5V rail with the sensor connected to it by a protective arrangement of resistors and diodes ( the voltages produced are varying by the speed of magnetic field changes, and may be way off the transistor limits). You can use any 'inverter' or NAND gate for this function but if you gooffed the multiple chip says "bye, bye!" (read the opening line;^))

Have fun

Stanislaw Slack user from Ulladulla

I believe the LM2917 would be helpful. You can get both a square wave and DC proportional to the RPM out of it, and it will run on 12V.

W.J. Lentz

Please bottom-post, it's the convention here.

You still haven't said what voltage is coming from this sensor - it makes a significant difference in what kind of circuit you use.

Thanks, Rich

I did this from a brake sensor in the rear wheel of a car. The problem to solve was: a: safety. Solved by picking the signal off with a 10Mohm resistor,so whatever you do to the other end,it will not change the sensor voltage. b: From low speed to high speed the signal varied between zero and 300 volts. Solved by putting a capacitor to ground, differentiating to get rid of the speed dependency. It turned out to give a signal of 4 volt peek to peek, flat from almost no speed to top speed. Applied that to a CMOS smittrigger,where the protection diodes of the gate lifted the signal to between 0 and 4 volts,and a nice square output from .3 miles per second to 150 MPS. Used that to trigger the interrupt bit of printer port on my computer, and presto, had a nice speed readout. The interrupt speed turned out to high, took care of that with a 4 bit counter to reduce frequency. Your signal should behave somewhat the same way, but you might need different components, so you have to do some experimenting.

The voltage coming out of the sensor varies with speed of flywheel it goes between

Rich Grise wrote:

more

Are you saying that your firt sending a signal through a resistor than grounding it with capacitor than through a schmitt trigger, and than you used a 4 bit counter to lower the frequency.

Sjouke Burry wrote:

Yep.

...

The speeds you mention are fairly high (.3 miles per second is 1080 miles per hour, and if MPS is meters per second, that's around 335 miles per hour, or if you again mean miles per second, 540000 miles per hour) so it's perfectly understandable about the interrupt speed running high.

-jiw

Ha. mph you jester.(I am used to km/uur)