Testing the Non-Inverting Amplifier

The non-inverting amplifier is an output stage the multiplies its input voltage by a factor of 247 or so. This converts the signal to either all the way on, or completely off. It turns the small sensed signals into a square wave for the coil. How do you tell if it's working?

To review the non-inverting amplifier design, go here.

See if it's Working

Are your optodetectors working yet? Good, you need touse them to exercise this stage. Assuming that everything is plugged in and working so far...

• First, leave the light beam unblocked. The voltage at this input (pin 3) should be at least a little above zero volts. Measure the output (pin 6) and it should be nearly the same as your positive power supply.
• Now block the light beam with the tip of your finger. Use just enough to block the signal detector, but not enough to block the reference detector. Measure the output here (pin 6) and it should be about the same as your negative power supply.
• If it didn't work, then make sure the chip is not backwards. And make sure that +15v is on pin 7 and -15v is on pin 4.