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Microprocessor generates programmable clock sequences - 05/12/05 EDN-Design Ideas imulate radar and sonar returns with simple circuit Design by William Grill, Honeywell BRGA, Lenexa, KS Momentary Touch Activated Switch - A single 1.5v silver oxide button cell powers this complete touch activated switch circuit for 5 years. It features both a normally open and a normally closed set of solid-state switch thermals. It also has an adjustable sensitivity, which can be set for a touch capacitance change as small as 1 picofarad. . . . Hobby Circuit designed by David A. Johnson P.E.-January, 2002
Monitors Pump Motor - This circuit solves this problem in a novel way. It clips on the outside of the pump motor’s power cable and provides a transistor switch closure whenever the circuit detects current flowing to the motor. The circuit draws so little current that a small lithium cell will power the circuit for yearsCircuit Solution by Dave Johnson P.E.-November, 2004
Motion Alarm using piezo Device - An inexpensive piezoelectric device is used as a motion sensing device for this motion alarm. . . Circuit by David A. Johnson P.E.-July, 2006
Motor-controller uses fleapower - 09/25/03 EDN-Design Ideas A simple, permanent-magnet dc motor is an essential element in a variety of products, such as toys, servo mechanisms, valve actuators, robots, and automotive electronics. In many of these applications, the motor must rotate in a gi Design by Anthony Smith, Scitech, Biddenham, Bedfordshire, UK
NanoPower LC Colpitts Oscillators - Circuit Ideas for Designers App Note__ Advanced Linear Devices, Inc
New Comparators Feature Micropower Operation Under All Conditions - DN137 Design Notes__ Linear Technology/Analog Devices
New Micropower Low Dropout Regulators Ease Battery Supply Designs - DN121 Design Notes__ Linear Technology/Analog Devices
Nine-Volt Battery Eliminator - If you use 9v battery powered devices for long periods of time, you may get tired of constantly changing batteries. The circuit below can be wired into any 9v battery powered device, drawing power from an external AC to DC power adapter. I designed the circuit. . . Circuit by David Johnson P.E.-December, 2009
Nine-Volt Battery Voltage Monitor - This circuit turns on a LED whenever the voltage of a standard 9v battery connected to the circuit drops below 7.2 volts. It uses a LTC1440 comparator, which also contains a 1.18v reference diode. In standby mode, the circuit draws only 4uA. . . Circuit by Dave Johnson P.E.-July, 2006
One-Line Telephone Line Status Indicator - This circuit monitors one phone line. . . Circuit by Dave Johnson P.E.-June, 2000
Op Amp Comparator & Reference IC Provides Micropower Monitoring Capability Design Note 190 - DN190 Design Notes__ Linear Technology/Analog Devices
Optical Interrupter Draws Microamps - This circuit is great for battery-powered systems that use slotted type optical interrupters. It draws only 10uA from a 3v battery that should allow up to 5 years of operation from a lithium battery. . . Circuit by David Johnson P.E.-June, 2000
Oscillator Draws 2 Nanoamps - If you have hundreds of touch switches that need an excitation signal, then this circuit is what you need. Its 20KHz 20v peak to peak output signal can supply up to 3 watts of touch switch excitation power . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006
Over-Temperature Micro-Power Alarm - The circuit is powered for years by a single 3 volt lithium battery. It sounds an alarm when the temperature exceeds a certain point. With some minor changes the circuit could also be configured for an under temperature (freeze) alarm. The circuit uses a . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Piezoelectric Device used for Motion Alarm - An inexpensive piezo wafer is used to detect vibration and when the vibration is sufficient a switch is activated . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006
Piezoelectric Energy Harvester & 1.2V Secondary Rail - The LTC3388-1/LTC3388-3 are high efficiency step-down DC/DC converters with internal high side and synchronous power switches that draw only 720nA typical DC supply current at no load while maintaining output voltage regulation. The EN pin can be used to activate the LTC3388-1/LTC3388-3. For instance, in this circuit the __ Linear Technology/Analog Devices App Note, Jul 23, 2010
Pop Free Microphone On/Off Switch Circuit - This circuit uses a simple technique to eliminate the usual “pop” sound when an electret type microphone is switched on or off. The circuit is completely passive and will work on dynamic and electret type microphones. . . Circuit by David A. Johnson P.E.-February, 2002
Power-Miserly Voltage Reference Needs Just One Pin - 20-Aug-09 EDN-Design Ideas A capacitor holds a reference voltage so that the microcontroller pin can perform other tasks Design by Peter T Miller, Applied Inspirations LLC, Bethlehem, CT
Precision Fullwave Rectifier - I have used this handy circuit many times. It accurately converts an AC signal into pulsing DC, which can be filtered to provide an average of the input voltage. It works from millivolts to volts. The circuit shown requires a stable +5v reference if a. . . Circuit by David Johnson P.E.-February, 2002
Precision Ultra Lower Power Oscillator - This circuit works much like the classic 555 timer, but draws only about 1.5 microamps from a 3 volt battery. It is highly stable under varying temperature and supply voltages. . . Circuit by David Johnson P.E.-May, 2000
Pulse Generator uses Micropower - It is hard to design a pulse generator that produces clean logic pulses while drawing very low current. This circuit is designed to produce short 2mS pulses at a rate of one per second while drawing only 1 microamp from a 9 volt battery . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000
Pump Motor Monitor - This circuit can turn on a light or sound a beeper, whenever an AC line powered pump motor turns on. It is designed to detect the motor current using a small inductor placed on the outside of the motor’s power cable. No direct wire contact is needed. . . Circuit by Dave Johnson P.E.-November, 2004
Rectifier-Fullwave - I have used this handy circuit many times. It accurately converts an AC signal into pulsing DC, which can be filtered to provide an average of the input voltage. It works from millivolts to volts. The circuit shown requires a stable +5v reference if a . . . Hobby Circuit designed by David Johnson P.E.-February, 2002
Replace a Pushbutton Switch with this Infrared Safety Switch - Using a slotted optical sensor, this circuit can be used as a replacement for a large mushroom pushbutton safety switch . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006
Reset generator uses "fleapower" - 06/27/02 EDN-Design Ideas When a processor-controlled device must operate reliably, designers often choose to periodically reset the processor rather than rely on a watchdog configuration. In low-power systems, this periodic-reset circuit can consume a large part of the system's current budget or may fail to operate at low voltages Design by Philip Simpson, Maxim Integrated Products, Reading, UK
RFID Transponder-Low Power - This is the Grand Prize winner in the design category of the 1993 RF Design Awards Contest. This entry exhibited both innovative use of RF technology and an elegant implementation of that technology __ Designed by Raymond Page |
