SR036/SR037
Applications Information, continued
VN2460N8
Unregulated Voltage
Fuse
Vz
5.1V
220µF
120VAC
or
240VAC
5V Coil
Relay
Gate
HVIN
Source
VOUT
Logic
Control
Circuit
5.0V
SR037
GND
1µF
Figure 6: Driving 5V Relay Coils with Zener Diode Clamp
The circuit shown in Figure 6 uses the SR037 to supply a
regulated 5.0V for the logic control circuitry. A 5.1V Zener diode
is used in parallel with the 5.0V relay coil to ensure that the relay
coil’s maximum operating voltage is not exceeded. The Zener
diodealsoactsasthecatchdiodewhenthecoilisswitchedtothe
off state. An external series resistor is used to limit the amount
of Zener current.
TN2425N8
Unregulated Voltage
Fuse
220µF
120VAC
Gate
Source
VOUT
HVIN
SR036 or
SR037
VREG
GND
1µF
330Ω
330Ω
Figure 7: Driving LEDs from 120VAC
The circuit shown in Figure 7 uses the SR036 or SR037 to drive
12 high efficient red LEDs from a 120VAC line.The average LED
current is approximately 20mA.
06/13/02rev.12
1235 Bordeaux Drive, Sunnyvale, CA 94089
TEL: (408) 744-0100 • FAX: (408) 222-4895
www.supertex.com
©2002 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited.
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