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Suggestions, Tips & Rules of Thumb for Protoype Breadboards
Last Updated:  Thursday, April 07, 2016 02:27 PM


In most of the circuits I design, very little power supply decoupling is needed. Usually one 10uf aluminum capacitor or two 0.1uf ceramic capacitors across the supply (+ to -) (one on each side of the power supply bus) is all that is needed. If specific supply decoupling around ICs is needed it will be shown on the schematic.
Unless it is called out on the schematic, it is assumed that standard 1/4 resistors and 1N4148 diode are used. Larger sizes or other types will be called out on the schematic.
Remember, when the schematic calls for two components to be wired in series, such as a fixed resistor and a pot, or a capacitor and a resistor, you can always interchange the sequence of the components with no change in operation.
Use 0.5" spacing between vector pin centers for standard 1/4 watt resistors and 0.4" for the diodes. If necessary, you can go as close as 0.4" for the resistors and 0.3" for the diodes if space is a concern. In some designs you may have to stand up the resistors and diodes. That is OK. If standard resistors or diodes do have to be mounted on their ends install the Vector pins with 0.2" spacing so they face each other. Larger parts, like big capacitors, should not use vector pins, but be directly soldered to the circuit.
You will find it easier to load the vector pins in first, then solder the bottom of the circuit, before you actually load the pins with components. That way, you have a relatively flat surface to push against as you solder. If you do load the pins with components, always solder in the components with the lowest profile first.
Use a vector pin when a hookup wire has to be soldered to the circuit board as an input or output. Don't solder an external wire connection on the bottom of the board or through a hole. If connections have to be made to heavy 18ga wires, drill out one of the perf board holes and use the large size (0.062") Vector pins. For the 0.062" Vector pins, a 1/16" drill bit will be needed.
Use a quality soldering iron with a long pointed tip. The tip should be rated for 800 degrees. Believe it or not, less heat is applied to the components with a quick hot smoky flash than an long warm sizzle. Also, be sure to use good solder. In my book, there is none better than Alpha 60/40 in a 0.032" size.
I usually do not show power and ground pin connections on the usual logic ICs or op amps, since they are almost always configured in the same way (upper right hand corner being power and lower left hand corner being ground). I also often do not indicate IC pin numbers on multiple logic gates and devices. I leave off the pin numbers until the complete printed circuit board artwork has been mapped out. If I did select the pin numbers, they may not be the best for the final circuit arrangement. I will provide copies of the IC data sheets and expect the circuit board builder to decide which pins to use in the circuit.
Remember, when using C-Mos ICs, all unused inputs must be connected to either supply or ground.
When soldering certain 1% resistors and some capacitors and diodes, try to solder them so their values can be seen.
It is OK to not to use vector pins on some larger components like big capacitors or resistors. However, keep in mind that a part soldered without a vector pin may be difficult to remove later if required.
Use quality wire when wiring up test fixtures or circuits inside enclosures. Low current paths can use 24ga wire while those wires that may carry higher currents should use 22ga. Try to use color coding schemes when possible. Red is usually reserved for the positive voltage and either black or green is used for ground. It those designs that use a positive and negative power supply (+-15v) green should be used for the ground connections and black used for the negative voltage.
I find it easier to connect all the parts needed for a particular circuit without concerns about power and ground connections. After I have connected the parts I then find the nearest power and ground to complete the circuit.
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