MC14040B

http://onsemi.com

5

Figure 3. Timing Diagram

CLOCK

RESET

Q1

Q2

Q3

Q4

Q5

Q6

Q7

Q8

Q9

Q10

Q11

Q12

1

2

4

8

16

32

64

128

256

512

1024

2048

4096

APPLICATIONS INFORMATION

TIME−BASE GENERATOR

A 60 Hz sinewave obtained through a 1.0 Megohm

resistor connected directly to a standard 120 Vac power line

is applied to the clock input of the MC14040B. By selecting

outputs Q5, Q10, Q11, and Q12 division by 3600 is

accomplished. The MC14012B decodes the counter

outputs, produces a single output pulse, and resets the binary

counter. The resulting output frequency is 1.0 pulse/minute.

MC14040B

Figure 4. Time−Base Generator

Clock

Q5

Q10

Q11

Q12

13

12

10

9

1

2

4

5

8

1/2

14012B

6

1/6 of HC14A

≥20pF

1.0M

1.0 Pulse/Minute

Output

120Vac

60Hz

NOTE:

Ground MUST be isolated

by a transformer or

opto−isolator for safety

reasons.

1/2

14012B