Analog Circuit Troubleshooting Notes:

Week #1:

One of my biggest issues this week was figuring out how to effectively use the photocell. Instead of ordering the connections resistor, to photocell to LED, I connected the resistor to the LED, and the photocell separately connected to the LED without passing through the resistor. The charge from the battery that flows through the circuit takes the path of least resistance, so in order to make the photocell work correctly, it has to be on this path of least resistance, which involves directly connecting the resistor to the photocell. If it is separately connected to the LED the charge will not flow to the photocell, because it is on a path of higher resistance than the path through the resistor. In short, always remember the path of least resistance!
Always remember to finish connecting the LED to ground!
When reading schematics, pay attention to what’s connected to the center, and be sure to replicate this in the actual circuit.
Make sure to have a clear path from the power to the resistor to the LED. Without a resistor, the LED will burn out!

Make sure that the multimeter is set to the right setting, especially when attempting to measure both Ohms and Volts in one session.
When using the multimeter to measure voltage, connect the black test lead to ground using a black probe on the ground rail, that way, it will be able to measure the difference between 0V (ground) and the voltage of the point measured.
When measuring a resistor, be sure that it is not connected to itself (both legs are in the same row), otherwise it will yield a value of zero, which can provide misleading information.
Be sure to complete calculations as you’re measuring, that way you can check both your calculations and your measurements at the same time!
Always properly define V2 and V1 to avoid any confusion with the Vout formula.
Use the correct formulas for defining resistors in parallel and resistors in series.
Honestly, I’m not too sure why some of my calculations and measurements don’t match, and I hope to find out more over the next few classes!

Don’t be afraid of using a good amount of solder in trying to solder two things together!
Be careful to calculate the correct amount of resistance required for your battery, otherwise you will short circuit your battery and drain it!
Make sure to use the multimeter as the “wire” in measuring current.
Make sure you set the multimeter to the appropriate measurement: voltage, resistance, current etc. and be aware of what setting the multimeter is at when working.
It’s easy to check current measurements by adding them up to see if they equal the total current! Checking them with calculations is also useful.
Be mindful of the fact that your battery may not be exactly 9V! Measure to before to ensure accuracy in the calculations.

Make sure you set the input modes to DC, not ground, if you want to see them!
I burnt myself on the soldering iron! Nothing too devastating, just hurts my pride. Be careful!
When soldering the battery snaps, make sure you strip enough wire from the snap and the wire you are attaching, as this will make it easier to hook together.

Be careful when reading schematics! There’s only one right answer.
Take a video of the oscilloscope to see both channel 1 and channel 2, instead of a picture.
Pay close attention to the labels on the Op Amp; they will tell you where to plug everything in!
Use the correct equations for inverting and non-inverting amplifiers.

Be careful not to plug the potentiometer into ground directly! Use a black wire!
You can make the circuit look a lot cleaner and clearer by moving the leg of the potentiometer that you’re not using.
Be mindful of the amount of wires you’re using to connect the various components of the circuit. Some of them might be unnecessary!
Instead of guessing and checking the amount of capacitance that you need, some simple algebra can go a long way! (Low Pass: plug in highest frequency (20,000 Hz.), and lowest resistance value; High Pass: plug in lowest frequency (20 Hz.) and highest resistance value)
Make sure you’re plugged into the the right part of the audio jack, otherwise, you won’t get any sound!