LESHAN RADIO COMPANY, LTD.

3/6

Figure 1. Inverting Comparator

with Hysteresis

Figure 2. Noninverting Comparator

with Hysteresis

R2

R2

R2 + R3

R3

R2

Rref / / R1

−

+

−

+

10k

R1

R2

R3

10 k

1.0 M

R3

R2

1.0 M

10 k

R1

10 k

10 k

Figure 3. Driving Logic

Figure 4. Squarewave Oscillator

Logic

Device

(V)

k

W

CMOS

TTL

1/4 MC14001

1/4 MC7400

+15

+5.0

100

10

R1

T1 = T2 = 0.69 RC

f

[

7.2

C(

mF)

R2 = R3 = R4

R1

[ R2 // R3 // R4

−

+

+

−

+

C

330 k

R4

330 k

R3

R1

100 k

10 k

R1

T1

T2

R2

330 k

10

Figure 5. Zero Crossing Detector

(Single Supply)

Figure 6. Zero Crossing Detector

(Split Supplies)

D1 prevents input from going negative by more than 0.6 V.

R1 + R2 = R3

R3

≤

R5

for small error in zero crossing

10 k

D1

R1

8.2 k

6.8 k

R2

15 k

R3

+15 V

*

q

10 k

Dq

q

*

)

10 M

R5

220 k

R4

220 k

+

APPLICATION CIRCUIT

LR339