HowTo-Color (8) / Hacking Electronics / Simon Monk / 236-3 / Chapter 3
CHAPTER 3: Basic Hacks
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Case 2: When It’s Light When it is light, we have to consider the resistance of the LDR R1. The lighter it is, the lower the resistance of R1 and the more of the current otherwise destined for the base of the transistor will be diverted through R1, preventing the transistor from turning on. I think the time has come to build the project on breadboard. Figure 3-15 shows the breadboard layout, and Figures 3-16a and 3-16b the finished breadboard. When placing the LED on the breadboard, make sure you get it the right way around. The longer lead is the positive lead, and it should be on row 10 connected to R3. (See Figure 3-16a.) If everything is fine, you should find that when you cover the LDR, the LED should light (Figure 3-16b).
Construction Now that we have proved our circuit works, we can get on with modding the push light. Figure 3-17 shows the push light the author used. Unless you are very lucky, yours is likely to be
Figure 3-15 The light switch breadboard layout
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