QLF Filter Assembly Procedure

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Part 2 - Speaker Driver

Ok, so you see a LED flash. Big deal. Well, this means that the 87C750 is working ok. Great. Now, lets add some sound. The 87C750 takes care of generating a tone, but we need to add a transistor to help drive a speaker. We love those beeps....
  1. Install Q1 2n2222 so the emitter (tab) connects to GND
  2. Install R8 4.7K. Connect from +5V to Q1 - base (center)
  3. Install C5 (.01) between Q1 base and GND
  4. Install R9 100 ohms (1/8W). Connect from +5V to speaker
  5. Connect the other lead of the speaker to Q1 - collector
  6. Q1 base to 87c750-6
  7. Apply Power to the circuit. The speaker should beep CW "ok" then a continuous tone