Sensor circuit op amp issue

Thread Starter

BabySpinach

Joined Nov 11, 2016
2
Hello everyone,

I'm trying to interface a sensor driver circuit for a speed sensor on my Jeep automatic transmission.

The sensor is a standard variable reluctance sensor.

Here is the design diagram that I've built it off of: http://myplace.frontier.com/~chris83803/AW4_Sensor_Converter.pdf

Please note, I'm using an arduino as the microcontroller, instead of the chip in the schematic. As you can see, there is no issue with that and I had it working just fine on the breadboard.

I was able to get the sensor working successfully on my breadboard, but when I soldered it to a protoboard, it's outputting around 8.66 Volts constant. The VR does nothing, no pulses, and the pot changes about 0.8v.

I've triple checked the layout and tried rebuilding the grounds. Is there something stupid I'm doing differently here that I wouldn't do on a breadboard?

Here are pics of my (sloppy) protoboard module:
Front: http://i.imgur.com/luBtLOA.jpg
Back: http://i.imgur.com/zs3xoxB.jpg


I've detailed out some of the voltage readings I was able to take:
Here are the labeled voltages: http://i.imgur.com/kjdBkIz.jpg
Here is the top side for reference: http://i.imgur.com/1MdLmsA.jpg?1

The diodes tested good with a multi.

Thanks for any assistance!
 
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