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 |
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 . |
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. |
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 |
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. |
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
|
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. |
Transformerless Power Supply:
|
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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