MINIATURE ISOLATED AC/DC POWER SUPPLY
This circuit uses a novel approach to
produce a fully isolated and regulated 5 volts
@30ma from the 120vac power line. It uses two
tiny SCRs that alternately discharge two
capacitors through a miniature high frequency
transformer. The voltage spikes produced through
the transformer are rectified, filtered and
regulated. A very common 8 ohm audio impedance
matching transformer can be used for the
transformer.
Published in EDN, Feb. 17, 1992 |
CAPS PROVIDE VOLTAGE BOOST TO SERIES REGULATOR
This circuit adds some capacitors and diodes
to a traditional transformer type series
regulator circuit to extend the normal operating
range. It can insure regulation during low line
voltage conditions or it can squeeze a few more
watts out of a plug-in-the-wall power adapter
power supply. |
LOW POWER 12,000 VOLT POWER SUPPLY
If you need about 12,000 volts DC for an ion
generator this circuit might be the ticket. It
draws power from the 120vac power line but it
uses a small 6KV camera flash trigger coil. The
output signal is isolated from the power line.
Although the circuit can only deliver about 5uA
of current it can produce dangerous shocks, so
be careful. |
240VAC TO 5VDC
POWER SUPPLY
This is simple way to power some 5v logic from a
240vac source. If a 120vac power adapter is
used, the circuit will also work for 120vac
power lines. |
12 Volt to 9 Volt DC Converter:
Car Converter for12 Volt to 9V
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2 Watt Switching Power Supply:
from 6V to14V |
5 Volt DC From RS232 Signals:
The circuit of Figure1 produces a
semi-regulated5-Volt output from an
RS-232 port. Unlike a PC-mouse
supply or comparable that rely on
the modem-control signals DTR and
RTS, this one operates with a3-wire
port GND, Rx, and TX, and obtains
power only from the TX line. The
output current-about 8mA-is
sufficient for CMOS microcontrollers
and other low-power .
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6 to 12 Volt Converter: This
circuit can provide up to 800mA
of12V power from a 6V supply. The
circuit is simple, about 75%
efficient and quite useful.
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Circuit offers improved active
rectification: EDN-Design Ideas
/ Rectifiers convert ac signals to
dc. You can combine a diode and a
load resistor to create a half-wave
rectifier, provided that the
amplitude of the ac source is much
larger than the forward drop of the
diode (typically 0.6V).
Unfortunately, you can't use this
method to rectify signals that are
smaller than a diode drop... |
DC to DC Converter: will produce
a 85-Volt voltage from +3V, usable
for low power applications
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Fast Rectifier Circumvents Input
Level Effects: 12/22/94 EDN-Design
Ideas |
Full Wave Rectifier uses Current
Feedback Amps: 03/27/97 EDN-Design
Ideas |
Full Wave Rectifier uses Current
Feedback Amps: 07/20/95 EDN-Design
Ideas
|
High Speed Rectifier uses No Diodes:
03/30/95 EDN-Design Ideas
|
Method provides self timing for
synchronous rectifiers:
05/16/2002 EDN - Design Ideas /
Synchronous rectifiers are MOSFETs,
driven in such a way as to perform a
rectifying function. They often take
the place of diodes in the
output-rectification stage of
switching power converters, because
of their lower on-state power loss.
In power circuits, synchronous
rectifiers are often complicated to
use because of timing issues.. |
One 9 Volt Battery gives +18, +25,
+33V: This circuit is based on
MAX1044 is a charge pump converter.
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OpAmp Rectifier Signals Input State:
07/21/94 EDN-Design Ideas |
Output Adjustable Flyback Converter:
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Precision AC / DC Converters:
National Semiconductor Application
Notes,28-Jun-1996
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Precision Rectifier is Glitch Free
to 1 MHz: 05/12/94 EDN-Design
Ideas |
Precision Rectifier Reduces Ripples:
03/03/97 EDN-Design Ideas
|
Step Down Rectifier Makes a Simple
DC Power Supply:
EDN-Design
Ideas - A simple and useful
nonisolated rectifier features
voltage step-down operation,
acceptable Class A line-current
harmonics, inherent short-circuit
protection, and, optionally, a
regulated output |
Transformerless Mains Power Supply:
This power supply does not really
excel in power efficiency, but it is
the cheapest and most compact
solution for a small power supply.
Note that the low voltage output is
directly connected to the mains; it
cannot be used when the low voltage
part can be touched. With the
component values of the schematic,
the circuit can supply12V /15mA max.
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Transformerless Power Supply:
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True RMS Detector: National
Semiconductor Application
Notes,28-Jun-1996
|
Two OpAmps Make Fast Full Wave
Rectifier: 03/14/96 EDN-Design
Ideas |
Two Watt Switching Power Supply:
from 6V to14V |
Unregulated Power Supply:
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