SR036(2002) Ver la hoja de datos (PDF) - Supertex Inc
Número de pieza
componentes Descripción
Fabricante
SR036 Datasheet PDF : 7 Pages
| |||
Applications Information, continued
SR036/SR037
120VAC
or
240VAC
Fuse
VN2460N8
Unregulated Voltage
220µF
1N4001
Gate
Source
HVIN SR036 VOUT3.3V
GND
1µF
Logic
Control
Circuit
12V Coil
Relay
VN2110K1
Figure 4: Driving 12V Relay Coils
The circuit shown in Figure 4 uses the SR036 to supply a
regulated 3.3V for the logic control circuitry while the unregu-
lated voltage is used to drive a 12V relay coil. The operating
voltage for a 12V relay coil is typically very wide and can
therefore operate directly from the unregulated line.
Fuse
VN2460N8
Unregulated Voltage
120VAC
or
240VAC
220µF
1N4001
Gate
Source
HVIN
VOUT 5.0V
SR037
GND
1µF
Logic
Control
Circuit
1KΩ
5V Coil
Relay
2N3904
100Ω
Figure 5: Driving 5V Relay Coils
The circuit shown in Figure 5 uses the SR037 to supply a
regulated 5.0V for the logic control circuitry while the unregu-
lated voltage is used to drive a 5.0V coil relay. To overcome the
voltage variation of the unregulated line, a bipolar transistor is
used to drive the coil with a constant current. The resistor value
from the emitter to ground sets the desired coil current. For an
arbitrary coil current of 40mA, the resistor value can be calcu-
lated as:
R=
5.0V -
40mA
β
1KΩ - Vbe
40mA
,
where
Vbe
=
0.6V
and
β
= 100
= 100Ω
6
Share Link: 