Readme fixes

README.md

@@ -1,17 +1,20 @@
 # Op-Amp AC amplifier with highpass and lowpass filters
-* For use with [MCP6001](https://ww1.microchip.com/downloads/en/DeviceDoc/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf) or similar amplifier
+* For use with [MCP6001](https://ww1.microchip.com/downloads/en/DeviceDoc/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf) or similar amplifier.
 * Works with mV inputs centered around GND
 * Few components, 0603 passives for easy soldering
+* Schematic drawn on the PCB, so you don't need any stupid documentation
+* Designed at ELAB, the PCB can be found [here](https://elab.kth.se/parts?q=opamp&p=2048)
+* MCP6001 and "equivalent" amps can be found [here](https://elab.kth.se/parts?q=mcp&p=1630)
 
 ![Image](images/pcb.png)
 
 # Basic configuration
 
 ![Basic configuration](images/basic.png)
-## Behaviour:
+## Behaviour of the example configuration:
 * 11x gain
 * Bandpass 20Hz - 15kHz (approx, not textbook perfect!)
-* Vcc 3-5V
+* Supply voltage 3-5V
 * Makes 10mV signal centered around GND into a 110mV signal centered around 2.5V
 * Output centered arround VCC/2
 * To directly drive headphones you must add a DC blocking capacitor! (between OUT and your headphones, 100uF should be fine)
@@ -19,7 +22,7 @@
 ## Easy adjustments for people in a hurry:
 * More gain? -> Increase R2 with respect to R1
 * Pass higher frequencies? -> Reduce Clp or Rout (or both)
-* Pass lower frequencies? -> Increase both Rb+ and Rb- (same value!)
+* Pass lower frequencies? -> Increase both Rb+ and Rb- (both should be same)
 * Lower center voltage of output? -> Increase Rb+ relative to Rb-
 * Achive the opposite of any of the above? -> Do the opposite of any of the above
 
@@ -31,7 +34,7 @@ Note! The MCP6001 has a GBW of 1MHz. This means, if the gain is set to 100x, the
 * Since the op-amp does not have a negative voltage rail, the signal can not be less than GND
 * Therefore, the input must be biased - pulled towards some positive voltage
 * If Rb+ = Rb-, then the bias will be VCC/2 - the signal will be centered around VCC/2
-* Adjusting them relative to eachother allows you to pick a different center voltage
+* Adjusting them relative to each other allows you to pick a different center voltage
 * The parallel resistance of Rb+ and Rb-, together with C1 forms a HIGHPASS FILTER
 * Increasing the resistance lowers the pass frequency
 
@@ -41,9 +44,9 @@ Note! The MCP6001 has a GBW of 1MHz. This means, if the gain is set to 100x, the
 * MCP6001 has a GBW of 1MHz, so max frequency = 1MHz / gain (3db loss at that frequency)
 * If you need higher frequencies / more gain, you can use a different op-amp, like an LMV721
 
-## C2 makes the output centered around the biasing frequency
+## C2 makes the output centered arround the biasing frequency
 * Whatever voltage Rb+ and Rb- form, will be the center frequency of the output
-* In essance, the gain for DC is 0 (since the gain resistors R1 and R2 have not DC path to GND)
+* In essence, the gain for DC is 0 (since the gain resistors R1 and R2 have not DC path to GND)
 * C2 just needs to be big enough, when it is big enough it does not affect filtering
 
 ## Rout and Clp can be used for an output lowpass
@@ -61,7 +64,7 @@ Note! The MCP6001 has a GBW of 1MHz. This means, if the gain is set to 100x, the
 # Soldering tips
 
 ![Soldered board](images/soldered.jpg)
-* Solder under the stereo optical microscope
+* Solder under the stereo optical microscope, look into the eyepiece, not the LCD display
 * Start with the Op-amp
 * Then the resistors and capacitors
 * Last the pin header