Breadboard Module

Before the days of ICs, experimenters often wired discrete components by mounting them temporarily on a wooden board of the type used for slicing a loaf of bread. (Those good old days are clearly remembered by the author, who built his first crystal set — and thought of improvement modifications — in 1938. At that time, bread was usually purchased in the form of a whole loaf and then sliced at home. The author borrowed his mother s wooden breadboard for radio experiments and was punished for getting it dirty and full of nail holes.) 

The plastic breadboard module we will use has wires buried inside. Small spring-loaded sockets are also inside, wherever the square holes are visible. In Fig. 23.5, a long row of horizontal holes is all connected together, to one long bus wire. The bottom one can be used for ground connections (really just 

A short row of five holes (four vertical dashes in the figure shown here) is all connected to a buried vertical wire. Each other row is similarly connected to its 

A jumper wire of the right length can be taken from a kit of different sizes, or it can be made by cutting a piece of thin solid 22-gauge copper wire. Leadwires on resistors are bent to a U-shape, so each end can be poked into the breadboard holes. Thus the input wire and the 2.2K are connected together via a vertical row of holes. The other end of that 2.2K, and the lOK, and a wire going to pin 3 are all connected together via another row of holes. Input and output wires can be attached to clip leads. 

The lower the resistance between pin 1 and ground, the higher the amplification factor ( gain ). We want a moderate amount, so 2.2K is appropriate for this application. If too low a resistance is used, the gain is so great that stray noise starts oscillations, and the loudspeaker will spontaneously howl. If this happens even with 2.2K, a larger resistor should be tried. 

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Figure 4.76 Breadboard modulation gain Bode plot.

The modulation gain of the test circuit was also measured. The modulation gain is the gain from the output of the opto-coupler to the output of the STR-F6524 average mode model. The breadboard results are shown in Fig. 4.76, and the IsSpice results are shown in Fig. 4.77. 

Our first step was the construction and testing of a breadboard model of the system, as shown in Figure 2. In this configuration, a conventional automotive turbocharger (in the foreground) was coupled to the scroll compressor portion of the First Generation Compressor/Expander Module (in the... 

The 386 is in the form of a "dual in-line package (DIP)." The black material is injection-molded epoxy polymer, with carbon black added to prevent random light from putting stray voltages on the PN junctions of the IC. Two lines of leadwires stick out of the bottom, like the legs on a centipede insect. It is difficult to attach clip leads to these, so a "breadboard" socket module will be used. This will provide useful experience for the experimenter, since these modules can be helpful in future circuit building. 

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