U2102B Datasheet, PDF (6/19 Pages) TEMIC Semiconductors – Multifunction Timer

In the case of AC loads, it is necessary to distinguish the power supply purposes of the individ-
ual operating modes. In reverse phase control mode (see Figure 3-1 on page 5), pin 15 must be
additionally supplied with power via a dropping resistor, since no current flows in pin 16 when
the power switch is switched on. Here, the dropping resistor, R₁, is connected to the AC line and
has therefore only one mains half-wave. R₁ is then calculated as follows:
R_1max
=
0.85 ×
V_{-----N---m----i-n----–-----}V_----S-
2 × I_tot
Figure 3-2. Power Supply in Reverse Phase Control Mode for AC Loads
Sync.
16
Voltage
limitation
+V_S
15
Push
pull
Temp.
monit.
14
GND
13
R_syn
D₁
R₁
C₁
R_G
IGBT
R_sh
Load
V_mains
In two-wire systems, the additional power supply at pin 15 is not possible (see Figure 3-1 on
page 5, by omitting R₁ and diode D₁). In this case, the resistor R_sync is identical with R₁ and
should be as low as the power dissipation allows it. A sufficiently large residual phase angle
must remain in this case to guarantee the device’s supply.
The power supply is simplified if the device is operated as a static zero-voltage switch for AC
loads (see Figure 3-2). All delay times are then twice as long, since the synchronization of the
module is connected directly to the AC line.
6 U2102B
4767B–INDCO–10/05