The three groups of series resistors on the PC board in Figure 4–84 are connected in series with each other to form a single series circuit by connecting pin 2 to pin 4 and pin 3 to pin 5. A voltage source is connected across pins 1 and 6 and an ammeter is placed in series. As you increase the source voltage, you observe the corresponding increase in current. Suddenly, the current drops to zero and you smell smoke. All resistors are 1/2 W.

Data in Figure 4–84 

(a) What has happened? 

(b) Specifically, what must you do to fix the problem? 

(c) At what voltage did the failure occur?

Transcribed Image Text:

R10 R₁ R₂ R6 12 R₁ R11 FIGURE 4-84 R3 R₁ R12 Rg 3 4 5 6 Top R5 Rg O DI 6 5 4 3 Bottom 21