sames

sames

SA2002H

7/12

http://www.sames.co.za

Direction indication (DIRO)

Note that the DIR output is not available in the DIP-8 package

type. Figure 9 shows the behavior of DIR, when energy

reversal takes place. The time period for the DIR signal to

change state, t , is the time it takes for the internal integrator

DIR

to count (down) from its present value to zero. Thus the energy

consumption rate determines the speed of change on DIR.

DR-01283

DIR

V

I

DIR

t

t

t

t

Figure 9: Measured energy direction on DIR

Mains zero crossing indication (FMO)

Note that the FMO output is not available in the DIP-8 package

type. The square wave signal of FMO indicates the polarity of

the mains voltage. Due to comparator offsets, the FMO low to

high transition can occur within a range as shown in figure 10.

The time between successive low to high transitions will be

equal to the mains voltage period.

Figure 10: Mains zero crossings on FMO

DR-01284

FMO

MAINS

t

V

t

t