DIY Schematics
- 1). Sketch out the signal chain. The order in which you place the circuit-mounted components, such as resistors, capacitors and transformers dictates the function of the circuit. The term "signal chain" refers to the collective components in linear order. Put the first component --- typically a power transformer --- on the extreme left. Each subsequent component goes to the right. For example, if you are building a guitar distortion pedal, the power supply is the first component and the output jack is last component.
- 2). Draw a large rectangle on a separate piece of paper. Make the rectangle as large as possible. Although a rectangle makes a neat frame for a circuit diagram, it also indicates that the diagram inside is that of an integrate circuit.
- 3). Draw the symbol for the first component at the top left of the rectangle. For example, if the first component is a battery, draw a 40 mm horizontal line joined to a 20 mm horizontal line. Draw a 10 mm horizontal line 10 mm to the right of the first. Join a 40 mm horizontal line to the second vertical line.
- 4). Cross-reference your signal chain diagram with a symbol schematic reference to accurately plot each component symbol in the circuit. Your symbols should be clear and unambiguous.
- 5). Write the component values next to each circuit-mounted part. Each component has a function and a value. The values are measured differently according to the function. Batteries have polarity, resistors have resistance and capacitors have capacitance. For example, if the first resistor has a value of 12,000 ohms, write 12k and sketch the ohm symbol. The ohm symbol is similar to a horseshoe shape, with two horizontal lines joined to each end.
- 6). Illustrate connection methods, where applicable. Some components need to be connected to others to operate properly. For example, if a power transformer is not connected to a capacitor, it has nowhere to discharge its current. Other parts may not be connected. Draw a heavy black dot over connected wires. Illustrate wires that cross but are not connected with a horizontal line.
- 7
The key should be clear and easy to read.Jupiterimages/Photos.com/Getty Images
Draw a key on a separate piece of paper, or on the back of the schematic. Draw the symbol for each component in the circuit, starting with the most common component in your particular circuit. Write the name of the component next to the illustration. Write the product serial number, where necessary. For example, if your circuit calls for a high-specification diode, include the serial number.
