Experimental Alternator Controller - Here is the schematic for the automatic charger I have been using for my kids' battery cars. The charger is a small molded unit that probably doesn't supply more than an amp and this circuit would have trouble with much more. No current limit is provided by this circuit - It relies on the charger for that. The circuit could be modified to provide more current by scroll down to find this one __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Finesse Regulator Noise - System designers often find themselves battling power supply hum, noise, transients, and various perturbations wreaking havoc with low noise amplifiers, oscillators, and other sensitive devices. Many voltage regulators have excessive levels of output noise including voltage spikes from switching circuits and high flicker noise levels from unfiltered references __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Floating Supply for LCD Panel Meter - NOTE: Scroll down - Did you ever install one of those low-cost LCD panel meters in a project only to discover that it requires a floating power supply? I just did! The meter cannot share a DC ground with the voltage to be measured. The above circuit came to the rescue. it draws about 4 or 5 mA from the 9 volt supply and can supply up to 2 mA at 9 volts to the LCD meter or other load but the two capacitors isolate the grounds. Works like a champ! __ Contact: Charles Wenzel of Wenzel Associates, Inc.
High Current LM317 Regulated Power Supply - 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. __
High Current Regulated Supply By LM317 - 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__
High Voltage Breakdown Tester - (Not for beginners!) The following circuit is used to determine the breakdown voltage of electronic components without causing permanent damage. The circuit quickly ramps the high voltage up from zero and stops when the leakage current reaches a preset amount up to 100 uA. When power is applied the two-transistor flasher circuit drives the complimentary-symmetry output stage with a square pulse at about 3 or 4 kHz(set by the 0.02 uF capacitor). The output stage is connected to the speaker winding of an audio transformer from an old tube radio and the transformer steps the voltage up to about 250 VRMS . __ Contact: Charles Wenzel of Wenzel Associates, Inc.
High Voltage Generator for Low Current Applications - Scroll to this one -- Here is a simple circuit for generating over 100 volts from a 12 volt source for powering low current devices and experiments. The two transistors may be 2N4401 and 2N4403 or similar for lower power applications or higher power devices for heavier loads. if more power is desired then lower the two 10 ohm emitter resistors to 3.3 ohms. When driving power transistors, more drive may be achieved by adding two more gates and resistors in parallel with the two output gates shown. Notice that the two driver gates are simply in parallel with 220 ohm current limit resistors in series with their outputs. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Homemade "B" Battery - i recently purchased a couple of old battery-powered tube radios on eBay with the idea of using their cases to house a transistor radio project. But these radios were so nice that I couldn't bring myself __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Hot Swap & Buffer I2C Buses - DN263 Design Notes__ Linear Technology/Analog Devices
Hot Swap Meets Infiniband Specification - DN265 Design Notes__ Linear Technology/Analog Devices
Hot Swapping the PCI Bus - DN155 Design Notes__ Linear Technology/Analog Devices
Hot-Swap Allows Two Computers to Monitor an RS-232 Channel - 05/29/08 EDN Design Ideas: A hot-swap serial-interface circuit allows two computers to monitor all the traffic on an RS-232 port __ Circuit Design by Jeff Patterson, All Weather Inc, Sacramento, CA
Hot-Swap Controller Handles Dual Polarity - 12/11/03 EDN Design Ideas: Some applications require a hot-swap controller, a circuit-breaker function, or both for dual-polarity, dc-input power-supply rails. in some hot-swap cases, the requirement is based only on inrush-current considerations. Control of __ Circuit Design by Dan Meeks, Texas Instruments, Manchester, NH
Hot-swap structure offers improved redundancy - 01/09/03 EDN Design Ideas: For redundancy purposes, a number of power supplies, using ORing diodes, can work into the same load. During maintenance, when you can remove any power supply, the minimum possible power perturbation at the load is desirable. To compensate for the voltage drop across the ORing diodes, you must connect the power-supply feedback lines after the diodes, at the load __ Circuit Design by Samuel Kerem, Corvus Corp, Columbia, MD
Increasing Regulator Current - An outboard pass transistor used to increase the current output of a voltage regulator IC . __ Designed by Andy Collison
Line Power Supply - This circuit provides a regulated output without a power transformer. it is similar to common circuits, except that a zener diode is replaced with an SCR. This is far more robust against line voltages surges than a zener diode version, plus there is no h __ Designed by Andrew R. Morris
LM317 Regulator with Pass Transistor - The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the 317 input and a resistor placed in series with the emitter of the pass transistor. in the figure below, the pass transistor will start conducting when the LM317 current reaches about 1 amp, due to the voltage drop across the 0.7 ohm resistor __ Designed by Bill Bowden
Low Voltage Hot Swap Controller Ignores Backplane Noise & Surges - DN319 Design Notes__ Linear Technology/Analog Devices
LT1120A-Micropower Regulator with Comparator & Shutdown - Switching Regulator__ Linear Technology/Analog Devices
LT3465-1.2MHz White LED Step-Up Converters with Built-In Schottky in ThinSOT - LT3465 Switching Regulator__ Linear Technology/Analog Devices
LT3465A-2.4MHz White LED Step-Up Converters with Built-In Schottky in ThinSOT - Switching Regulator__ Linear Technology/Analog Devices
LTC1645 Dual Channel Hot Swap Controller/Power Sequencer - DN217 Design Notes__ Linear Technology/Analog Devices
LTC1646: Power Supply Isolation Controller Simplifies Hot Swapping the CompactPCI Bus for 5V-/3.3V-Only Applications - DN253 Design Notes__ Linear Technology/Analog Devices
Micropower Regulator with Comparator & Shutdown - Switching Regulator__ Linear Technology/Analog Devices
Misc. Regulator Circuits - NOTE: Scroll down - This simple regulator provides excellent performance when the input voltage is several volts above the output voltage. The output voltage is set by the zener and is approximately 0.6 volts above the zener's rating. __ Contact: Charles Wenzel of Wenzel Associates, Inc.