Lab 4

Forward Engineering. Using one of the schematics listed below, design a printed-circuit board to build a working copy of the circuit. Assignment:

1. Look up the referenced Application Note and read the description of the circuit
2. Compile a bill of materials and find sources for all the parts (including stock numbers and cost)
3. Enter the schematic into the layout tool
4. Produce the necessary PCB layout files for fabrication
5. (Optional) Simulate the circuit in LTSpice (there are fewer weird ICs here)

The following circuits were all designed by Jim Williams, and the schematics appeared in application notes published by Linear Technology.

• Tachless motor speed controller (App Note 11, page 8)
• Fast response V/F converter (App Note 14, page 4)
• Single-cell V/F converter (App Note 15, page 1)
• Low-distortion sine-wave oscillator (App Note 43, page 33)
• Complete AM radio station (App Note 47, page 52)
• High-speed avalanche pulse generator (App Note 47, page 93)
• Triggered pulse generator (App Note 61, page 21)
• Stabilized sine-wave generator (App Note 98, page 3)
• Output-leveled noise generator (App Note 106, page 11)

In choosing a circuit, be sure that you can find all of the necessary components.  Some parts my be substitutable, some may not.  If you have any questions about part substitutions, please ask. 

For a more complicated project, the following circuits provide additional challenges.

• King Kong V/F converter (App Note 14, page 2).  The output frequency goes up to 100 MHz, and this circuit leverages fast components and requires careful high-speed layout.
• Op amp with 120-volt output stage (App Note 18, page 7). With lethal voltages present, this circuit requires careful layout and construction to prevent circuit damage and engineer injury.  If you choose this circuit, power the circuit from a lower voltage (like plus/minus 48V) for initial testing.
• Son-of-Godzilla amplifier (App Note 21, page 8). This amplifier has a bandwidth over 100 MHz and a tendency to destroy itself. Read the adjustment procedure carefully.
• The Zoo Circuit, a micropower V/F converter (App Note 23, page 11).  The development of this low-power circuit is also described in one of his books.
• 28VDC-to-110VAC sine-wave power converter (App Note 35, page 15). Again, with lethal voltages present, this circuit requires careful layout and construction to prevent circuit damage and engineer injury.  If you choose this circuit, power the circuit from a lower voltage (like plus/minus 48V) for initial testing.

Substitutions:

• Substitute 2N3904 transistor for 2N2369 (for now, try other substitutions later)
• Substitute 1N5711 Schottky diode for HP5082-2810