Sensors

6

Freescale Semiconductor

MC14568

Figure 3. MC14568 Timing Diagram for the Timer Circuit

Figure 4. MC14568 Oscillator Waves in Stand By and Smoke Conditions

Pin 12 OSC CAP

Pin 1 TIMER START

Internal Clock

Pin 4 TIMER OUT

Pin 5 LED

Check for Smoke Window

231 Clock Cycles

6 Clock Cycles

Time

Time

Time

Time

Time

Time

Time

10 ms

1.67 s

40 ms

10 ms

Check for Smoke Window

Check for Smoke Window

SMOKE

NO SMOKE