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12 Volt DC Power Supply:
This is a simple low-cost 50W off-line
switching power supply, which can be used for home projects or to learn
operation of flyback converters. It can work over a universal AC line
input range 90-264 VAC and provides a 12VDC output at more then 4A load.
Line and load regulation is better then 0.5%. (added 11/07) |
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12 Volt to 9 Volt DC Converter: Car Converter for12 Volt to 9V (Electronic Schematic / circuit added 4/02) |
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120 VAC Lamp Dimmer (full wave SCR): (Circuit / schematic design added 6/06) |
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120 Volt AC Lamp Dimmer (Full Wave SCR): (Circuit / schematic design added 6/06) |
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12W AC-DC Flyback converter: Fully assembled and tested power supply with DC containing all design documentation Features:
Universal AC line input, 0-1A Iout @ 12V, 84% efficiency at high line, Short Circuit protection, Over Voltage protection (circuit design added 3/05) |
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2 Watt Switching Power Supply: from 6V to14V (Electronic Schematic / circuit added 4/02) |
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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. (Electronic Schematic / circuit added 4/02) |
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600 Volt Power Supply: simple 600 Volt DC power supply. Convert 230V AC to 300V and 600V DC. . (Circuit added 9/04) |
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60W AC-DC Flyback converter: Universal AC line input Fully assembled and tested power supply with DC containing all design
documentation Features: 0-4A Iout @ 15V, 87% efficiency at high line, Short Circuit protection, Over Voltage protection (circuit design added 3/05) |
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90W AC-DC Flyback converter: Fully assembled and tested power supply with DC containing all design documentation Features:
Universal AC line input, 0-6A Iout @ 15V, 83% efficiency at high line, Short Circuit protection, Over Voltage protection (circuit design added 3/05) |
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App Note 35 - PWM AC-DC Power Supply Design: Apex Microtechnology Corp - App Note - (app note 6/06) |
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Circuit Forms Constant Current SCR: 02/01/01 EDN-Design Ideas / (Circuit / schematic design added 6/06) |
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Circuit offers improved active rectification: 02/06/03 EDN-Design Ideas / (Electronic circuit added 10/03) 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... |
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DC-to-DC Converter: will produce a 85-Volt voltage from +3V, usable for low power applications (Electronic Schematic /
circuit added 4/02) |
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EPR-32: 25 W Multiple Output TOP245P Supply: This design kit is an AC-DC power supply with universal input and 4 outputs.
The design, rated for 20 W (25 W peak), is implemented using a TOP245P device from the TOPSwitch-GX IC family and an EEL25 core in a flyback topology. (circuit design added 3/05) |
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Fast Rectifier Circumvents Input Level Effects: 12/22/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) All
diode-based rectifier circuits suffer from a signal-level-dependent frequency response. This response occurs because the dynamic impedance of the diodes varies as the signal level changes. The
result is a slower frequency response and distorted rectified outputs at low signal levels compared with high levels. An alternative approach to a half-wave rectifier is to use the
input-signal polarity to control the signal channel gain. The input signal shuts down the gain for one polarity and passes the signal on for the other.... |
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Full wave rectifier operates to 200 MHz: 07/20/95 EDN-Design Ideas / (added 10/05) The circuit in Figure 1 uses
current-feedback amplifiers to implement a wideband full-wave rectifier for applications such as a control/AGC system reference or as an amplitude indicator. Putting the full-wave-rectifier
diodes in the feedback loop of an op amp works better than does using simple diode-based rectifiers. The op amp's loop gain decreases the distortion and offset voltage that the diodes
introduce. Simple diode rectifiers also require large signals and are temperature-sensitive. The op-amp technique works well for signal frequencies to about 500 kHz,... |
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High Speed Rectifier uses No Diodes: 03/03/95 EDN - Design Ideas / (added 03/03) Fig 1 shows a
high-speed, full-wave rectifier-or absolute-value circuit-that uses a high-speed clamping amplifier, IC2. This circuit is faster and performs better than rectifiers employing diodes in their
amplifiers' feedback paths. These diode-based circuits have limitations at lower signal-input levels and higher bandwidths. These limitations show themselves most clearly as crossover
distortion. This circuit cleanly corrects a 20-MHz, 600-mV p-p input sine wave (50(ohm) back-terminated). The circuit employs IC2's clamping action while IC1 and IC3 function as a buffer.... |
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Introduction to Schottky Rectifiers: MicroNote 401 from Microsem (Circuit / schematic design added 6/06) |
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LB-8: Precision AC/DC Converters: National Semiconductor - Application Note (added 2/06) |
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Method provides self timing for synchronous rectifiers: 05/16/02 EDN Design Ideas / (added 1/05)
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.... |
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MOSFET Switch Provides Efficient AC/DC Conversion: 02/17/00 EDN-Design Ideas / (Circuit / schematic design added 6/06) |
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One 9 Volt Battery gives +18 +25 +33V: This circuit is based on MAX1044 is a charge pump converter. (Electronic Schematic /
circuit added 4/02) |
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OpAmp Rectifier Signals Input State: 07/21/94 EDN-Design Ideas / (added 6/03) The op-amp rectifier in Fig 1 operates from a
single supply and provides a logic output and an LED that indicate the state of the input voltage. The input-state indications are handy for calibration. Because the circuit operates from a
single supply, the 2.5V reference determines the level around which the circuit rectifies input waveforms.... |
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Output Adjustable Flyback Converter: (added 6/03) |
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Precision AC/DC Converters: National Semiconductor Application Notes,28-Jun-1996 (app note added 4/02) |
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Precision full wave signal rectifier needs no diodes: 09/1/05 EDN -- Design Ideas / (added
11/05) Single-supply design uses two op amps. |
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Precision Rectifier is Glitch Free to 1 MHz: 05/12/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) The
manufacturer’s circuit for a precision, current-mode, full-wave rectifier (Fig 1a) converts a voltage signal to a current, eliminating errors arising from voltage drops across the rectifying
diodes. However, just like op-amp-based rectifiers, the circuit in Fig 1a requires closely matched resistors. The circuit in Fig 1b obviates the precision resistors by simply returning
the diodes to the input. For a positive signal current, D1 is on, and the current flows into the load resistor to develop an output voltage. When the input signal current is negative, D2
is on, passing current to the low-impedance.... |
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Precision Rectifier Reduces Ripples: 03/03/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) You can use a
lowpass filter to simultaneously increase a rectifier's speed and reduce or maintain the ripple voltage. The input voltage of the precision rectifier in Figure 1a is 100 mV at a frequency of
50 Hz. The output with C1 equal to 0 is a double phase-rectified voltage of R2/R1 times the top value of the input voltage. With R2=33 k(omega) and R1=22 kiliohms, the result is 150 mV. If
C1=560 nF, the amplitude has an average value of 95 mV, and the ripple is 10 mV p-p. The circuit reaches this output within 80 msec, but the ripple is fairly high. You can increase the value
of C1--to 22 µF, for example--which reduces the ripple to 0.3 mV p-p, but the circuit now takes 5 sec to reach the output. When you feed the output of the rectifier to a lowpass filter (Figure
1b) you can reduce.... |
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PWM AC-DC Power Supply Design - App Note 35: Apex Microtechnology Corp - App Note - (Circuit / schematic design added 6/06) |
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SCR Voltage Regulator: Though not as accurate as a linear or a high-frequency switching regulator, an SCR voltage regulator
wastes little power and creates no RFI. Designed by
Andrew R. Morris
(Circuit / schematic design added 6/06) |
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Silicon Controlled Rectifier Model Railroad Throttles and London Model Railroad Group SCR Throttle: The following is a
schematic drawing of a Silicon Controlled Rectifier type throttle for use on larger scale model railroads. Three versions of this throttle are shown on this page. They are not sophisticated
designs but work well and are tough and reliable. (added 2/05) |
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Step Down Rectifier Makes a Simple DC Power Supply: 04/09/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)
-- 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 |
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Supply uses ac to generate 5V Power on reset: 05/16/02 EDN Design Ideas / (Electronic circuit design added
02/05) The need often arises for a low-cost logic supply for powering microcontrollers and related circuitry in "white-goods" products, such as industrial controllers and sensors. These
applications usually include 24 or 115V ac or higher levels of ac voltage for conversion to 3.3 or 5V dc. The simplest approach to generating low-current logic-supply levels is to apply the
rectified and filtered ac in...... |
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Thermostat for 1KW Space Heater (SCR controlled): Here is a simple thermostat circuit that can be used to control a relay
and supply power to a small space heater through the relay contacts. The relay contacts should be rated above the current requirements for the heater. Temperature changes are detected by a
(1.7K @ 70F) thermistor placed in series with a 5K potentiometer which produces about 50 millivolts per degree F at the input of the LM339 voltage comparator. The two 1K resistors connected to
pin 7 set the reference voltage at half the supply voltage and the hysteresis range to about 3 degrees or 150 millivolts. The hysteresis range (temperature range where the relay engages and
disengages) can be adjusted with the 10K resistor between pins 1 and 7. A higher value will narrow the range.... (Circuit / schematic design added 6/06) |
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Transformerless DC/DC converter produces Bipolar outputs: 04/29/04 EDN Design Ideas / (added 1/05) The
conventional way to produce dual (positive and negative) outputs from a single positive input is to use a transformer. Although such designs are relatively simple, the transformer inherently
introduces the problem of size. It can be challenging to fit a transformer into an application in which it's important to minimize the circuit footprint and height.... |
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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. (Electronic Schematic / circuit added 4/02) |
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Transformerless Power Supply: (Electronic circuit added 7/03) |
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True RMS Detector: National Semiconductor Application Notes,28-Jun-1996 / (added 6/02) |
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Two OpAmps Make Fast Full Wave Rectifier: 03/14/96 EDN-Design Ideas / (added 2/06) The circuit in Figure 1 is a precision
full-wave rectifier with the following characteristics: Minimal delay time between the input and output (with only one op amp in the chain); Similar delay times for positive and negative
inputs; No need to match diodes or adjust resistors. When VIN>0V, the output of op amp IC1 is negative, so the reverse-biased diode D1 blocks the output path of IC1 to VOUT. The output
of op amp IC2 is positive, so the…. |
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Two Watt Switching Power Supply: from 6V to14V (Electronic Schematic / circuit added 4/02) |
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Unregulated Power Supply: (added 9/02) |
