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Secure Bootstrap Operation under Light Load - 05/12/11 EDN Design Ideas: Additional circuit lets a capacitor charge, preventing voltage dips. A previous Design idea highlights a potential issue of a bootstrap IC under light-load or prechargedload operation (Reference 1). The circuit in Figure 1, with the additional circuit in the green box, fixes the problem of a voltage dip in the bus-voltage signal. The waveforms in Figure 2 demonstrate how this problem takes place in buck converter IC 1B when its output voltage, VBUS, dips below the regulation point at a fixed rate under no load. By inspecting the other traces in Figure 2, you can conclude that the dip of VBUS occurs Design by Chee Hua How
Self Buffered Micropower Reference - The OpAmp provides controlled bias current to a shunt reference through its supply connection. Since the OpAmp can operate with both inputs and outputs at the low-side supply potential, the buffer action works properly for sourcing output current at the same voltage as the reference itself. __ Linear Technology/Analog Devices App Note, Jun 21st 2011
Self switching Power Supply - One of the main features of the regulated power supply circuit being presented is that though fixed-voltage regulator LM7805 is used in the circuit, its output voltage is variable. This is achieved by connecting a potentiometer between common terminal of regulator IC and ground. For every 100-ohm increment in the in-circuit value of the resistance of potentiometer VR1, __
Self-modifying code extends addressing Mode - 12/17/98 EDN Design Ideas: As just about any assembly-language programmer knows, self-modifying code (SMC) is usually undesirable, unintentional, and destructive. However, the SMC routine in Listing 1 is extremely useful to extend the indexed, 16-bit offset addressing mode of the venerable HC05 µC from 8 bits, or 256 locations, to the full 13-bit (8-kbyte) memory address space that the µC’s architecture supports. This routine is very useful for error tables, text messages tables, or any array manipulation for a large number of elements. Design Paul Sofianos, Motorola Inc, Tempe, AZ
Series Regulator with Q900 - This is a series regulator with Q900 being the control element, Q901 a driver, and Q902 an error amp. ZD900 forms the emitter reference voltage source. Since the generated high voltage and other voltages are linked by means of the magnetic field of T900, any change in H. V. will be reflected back to all of the other voltages. __ Designed by Chris Candreva
Serves as milliohmmeter - 04/15/04 EDN Design Ideas: When I was recently debugging a design, I discovered that a short circuit existed from a ground plane to a power plane. I did not have access to a milliohm meter or an equivalent tester for locating this type of short circuit. So, I logged onto the internet to find an easily constructible milliohm meter Design by AM Hunt, Lancaster Hunt Systems Ltd, Shepperton, UK
Servo loop improves linear-regulator efficiency - 8-Jul-04 EDN Design Ideas: Linear regulators are easy to implement and have better noise and drift characteristics than switching approaches. Their largest disadvantage is inefficiency excess energy dissipated as heat. Several well-known techniques are available to minimize the input-to-output voltage across a linear regulator Design by Aurel Gontean, Technical University, Timisoara, Romania
Servo Pulse to Voltage Converter - A while back a Discover Circuits visitor needed a way to convert servo pulses from a radio controlled device into a voltage. The drawing below, illustrates the pulse train of the received signal. The time between pulses is a fixed 20ms while the pulse widths vary from a low of 1ms to a high of 2ms . . . Hobby Circuit designed by David Johnson P.E.-August, 2005
Shunt regulator eases power-supply-start-up woes - 10/27/05 EDN Design Ideas: Ensure regulator start-up under light output load Design by Michael O'Loughlin, Texas Instruments, Nashua, NH
Shunt regulator improves power Amplifier's current-limit accuracy - 02/02/06 EDN Design Ideas: Additions protect output transistor and downstream circuitry Design by John Guy, Maxim Integrated Products Inc, Sunnyvale, CA
Shunt regulator provides overvoltage protection - 01/15/98 EDN Design Ideas: The circuit in Figure 1 uses a typical technique for varying the output voltage of a power supply via a programmable control voltage. Although the topology and schematic details of the power supply are not critical, the protection technique is noveL. This File contains several Design ideas, please scoll to this one This design idea by ROBERT N BUONO, MAHWAH, NJ Design by ROBERT N BUONO, MAHWAH, NJ
Shunt regulator serves as inexpensive Op Amp in power supplies - 09/15/05 EDN Design Ideas: Use low-cost power-regulator IC to replacecostly op amp in power supplies Design by Michael O'Loughlin, Texas Instruments, Nashua, NH
Shunt regulator speeds power supply's start-up - 12/16/05 EDN Design Ideas: Reconfiguring the start-up shunt regulator can reduce bootstrap time Design by Michael O'Loughlin
Signal Conditioning & Power Conversion - AN75 Linear Technology This publication includes designs for data converters and signal conditioners, transducer circuits, crystal oscillators and power converters. Wideband micropower circuitry receive special attention. Tutorials on micropower design techniques and parasitic effects of test equipment are included. __ Linear Technology/Analog Devices
Simple Circuit & Efficient Sub-2W Isolated Power Supply - The non-synchronous flyback topology is widely used in isolated power supplies ranging from sub watt power levels to tens of watts. With more green-mode standards emerging around the world, improving light load efficiency and reducing no-load input standby current are more demanding than ever. Unfortunately, the traditional__ Linear Technology/Analog Devices App Note, Min Chen Senior Design Engineer-Power Products Nov 5th 2012
Simple Circuit +/-22Voltage Regulator - The following diagram is provided for anyone who would like to include a voltage regulator but who does not want to use one of the IC versions (as in the updated, regulated supply for the 1996 design). This is a very basic regulator circuit, without any additional features such as foldback current limiting, and does not have the same performance as an IC regulator. __
Simple Circuit +5V power supply - This circuit is a small +5V power supply, which is useful when experimenting with digital electronics. Small inexpensive wall tranformers with variable output voltage are available from any electronics shop and supermarket. Those transformers are easily available, but __ Designed by Tomi Engdahl
Simple Circuit 3.3 volt power supply - Among the power supplies presented here, this is a well regulated type that can deliver up to 1.5A current from a wide range of input voltage of 5V to 25V dc. See LM317 calculator if you want to know how to get the 3.3 V output. __ Designed by KB Kaminski
Simple Circuit 78xx Current Booster - Volt regulators such as the LM708, and LM317 series (and others) sometimes need to provide a little bit more current then they actually can handle. if that is the case, this little circuit can help out. A power transistor __ Designed by Izhar Fareed
Simple Circuit Adjustable Voltage Source - A simple but less efficient methode of controlling a DC voltage is to use a voltage divider and transistor emitter follower configuration. The figure below illustrates using a 1K pot to set the base voltage of a medium power NPN transistor. The collector of the NPN feeds the base of a larger PNP power transistor which supplies most of the current to the load__
Simple Circuit DC Adapter Power Supply - DC voltage "virtual earth" circuits __ Designed by Rod Elliott ESP
Simple Circuit DC/DC converter increases available power in dual voltage system - 8-Jan-04 EDN Design Ideas: The schematic in Figure 1 shows a way to increase the power available from a current-limited 5V supply by adding power from a -5V supply. The DC/DC converter generates a single 12V, 150-mA (1.8W] output from two regulated and current-limited input sources at 5V, 300 mA (1.5W] and -5V, 300 mA (1.5W] Design by David Kim, Linear Technology, Milpitas, CA
Simple Circuit High Efficiency Step-Down Switching Regulator - DN73 Design Notes__ Linear Technology/Analog Devices
Simple Circuit Negative Supply Circuit - This simple circuit consists of two LEDs and a photo diode. it generates a negative voltage with a current level of a couple milliamps. it is ideal for supplying a negative rail to low power “rail to rail” op amp circuits, which need to have a true zero volts output. Note: This circuit is not particularly efficient . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006
Simple Circuit regulated power supply with overcurrent trip - Here's a circuit for a relatively simple regulated power supply which has well controlled characteristics, including a clever over-current trip. __ Designed by Richard Torrens
Simple Circuit Regulator Has One Active Part - 03/16/95 EDN Design Ideas: The regulator of unusual simplicity (ROUS) in Fig 1 derives a low-voltage, low-current output from rectified 115 to 270V ac. Pass transistor Q1 is the regulator's only active component. Design by Kennan C Herrick, ESI Electronics Corp San Francisco, CA
Simple Circuit regulator Monitors its input voltage - 09/12/97 EDN Design Ideas: Two- and three-cell portable systems, such as medical sensors, often monitor their battery input to obtain an early warning of a loss of battery voltage. Typically, this warning is a digital signal that a comparator generates and then sends to the microcontroller. The circuit in Figure 1 presets one side of a dual linear regulator to generate 2.84V at 100 mA. The other side operates open loop, as a comparator, to generate the low-battery warning. both side as are capable of delivering 100- mA output current. Resistors R1 and R2 determine the low-battery threshold, according to Design by Larry Suppan and Luong Huynh, Maxim Integrated Products, Sunnyvale, CA
Simple Circuit regulator provides ±12V - 10/23/97 EDN Design Ideas: Simple circuit can provide ±12V from a5V input using only one switching-regulator IC and a few off-the-shelf Design by Musiri Shrivathsan, National Semiconductor Corp, Santa Clara, CA
Simple Circuit serves as milliohmmeter - 04/15/04 EDN Design Ideas: When I was recently debugging a design, I discovered that a short circuit existed from a ground plane to a power plane. I did not have access to a milliohm meter or an equivalent tester for locating this type of short circuit. So, I logged onto the internet to find an easily constructible milliohm meter Design by AM Hunt, Lancaster Hunt Systems Ltd, Shepperton, UK
Simple Circuit Switching Regulator - NOTE: Scroll down - When batteries are used to power lower voltage circuits, a switching regulator is desirable to conserve battery life. There are excellent ICs that can do the job with great efficiency and small size. An example is the Maxim (www.maximic.com) MAX639 which converts inputs from 5.5 to 11.5 volts to 5 volts at up to 225mA. The only additional parts are an inductor, schottky rectifier and a couple of capacitors. The following circuit is a discrete switcher similar in power handling capability to the MAX639. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Simple Circuit technique improves transient Dynamics - 06/24/99 EDN Design Ideas: Designing low-voltage, high-current converters with fast dynamic performance places stringent demands on a system designer. However, a simple technique reduces the peak voltage deviation and decreases the response time for a tran Design by Robert Sheehan, Linear Technology Corp, Milpitas, CA
Simple Circuit temperature regulated FAN speed Controller - This regulator uses a P-FET to change the positive supply voltage to a FAN an NTC resistor mounted on the device that needs cooling will change the fan speed, the temperature on the heat sink will therefore be constant, while the FAN speed will change, depending on power disipated The RPM output signal from most FAN types will continue to function, __
Simple Circuit Ultra-Low Dropout Regulator - DN32 Design Notes__ Linear Technology/Analog Devices
Simple Circuit Variable Voltage Source - The high current regulator below uses an additional winding or a separate transformer to supply power for the LM317 regulator so that the pass transistors can operate closer to saturation and improve efficiency. For good efficiency the voltage at the collectors of the two parallel 2N3055 pass transistors should be close to the output voltage. The LM317 requires a couple extra volts on the input side, plus the emitter/base drop of the 3055s, plus whatever is lost across the (0.1ohm) equalizing resistors (1volt at 10 amps) , so a separate transformer and rectifier/filter circuit is used that is a few volts higher than the output voltage __ Designed by Bill Bowden
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