|
Cat Detector for a Cat Flap on a door. - This circuit uses one tuned
coil for on the door and just a single wire loop on the animals collar. When
the two coils come close together, it produces a signal that can cause a an
LED to light and also trips a solenoid to unlock the door so it can open.
Since all these doors are somewhat different, I leave ….(Circuit design
added 3/08) |
|
Ceiling Fanspeed Control - Ceiling Fan Speed Control - For one of
those 3 or 4 blade decorative fans…. [Reverse engineered schematic by Stepan
Novotill] |
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CFL Ballast for 26w/ Sprial Lamp 220Vac Input - The IRPLCFL5E
reference design is an electronic ballast for driving 26W compact fluorescent
lamps from 220VAC. The circuit provides all of necessary functions for
preheat, ignition and ...(added 3/05) |
[ad-smSQ.htm] |
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Charge Coupled Bi-Directional Power Mosfet Relay - The circuit uses
an inexpensive C-MOS inverter package and a few small capacitors to drive two
power MOS transistors from a 12v to 15v supply. Since the coupling capacitor
values used to drive the FETs are small, the leakage current from the power
line into the control circuit is a tiny 4uA. Only about 1.5mA of DC is needed
to turn on and off 400 watts of AC or DC power to a load. Published in
Electronic Design, Nov. 8, 1990. …. [Designed by David A. Johnson] |
|
Church Bell Controller (Antonis Pontikakis) - This circuit is a
church bell controller. Basic component is an ATmega32 microcontroller. At the
circuit 2 24LC32 eeprom memories is being used, the 1st for internal standard
melodies and the 2nd one is for user's compositions. ….(Circuit design added
08/08) |
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Circuit Automates Switch over between Battery & Source - 12/18/97
EDN-Design Ideas he use of a logic supply or an ac wall adapter can
extend battery life in a small portable system by offloading the battery.
However, managing the switch-over between battery and external power can be
messy. For high-cell-count batteries,.... [Design Idea by Len Sherman, Maxim
Integrated Products, Sunnyvale, CA] |
|
Circuit controls brightness of multiple displays - 30-May-02 Issue
of EDN I recently needed to control nine seven-segment displays for a
microcontroller's serial port. The complication I faced was the need to
provide a continuous brightness adjustment for all the digits—from completely
dark to fully bright. I couldn't easily use the obvious solution of a string
of 74HC595 serial-to-parallel converters driving the segments through series
resistors, because I wou.... [Design Idea by Stephan Goldstein, Analog
Devices, Wilmington, MA] |
|
Circuit controls intensity of reflex optical sights - 21-Feb-02
Issue of EDN A popular category of aiming/pointing aids is the reflex,
or "red-dot," sight. This system finds use in such diverse applications
as astronomy, archery, and shooting. In the reflex sight, light from an
internal source-typically a high-intensity red LED-reflects from a curved,
transparent optical (reflex] element through which you view the target....
[Design Idea by Stephen Woodward, University of North Carolina, Chapel Hill,
NC] |
|
Circuit Controls Isolated 12 Volt Stepper Motor - 09/26/96 EDN-Design
Ideas: Allows full direction and step control of a12V, four-phase
stepper motor from a5V, TTL/CMOS-compatible logic controller.… [Design Idea by
Martin O'Hara, Newport Components Ltd, Milton Keynes, UK] |
|
Circuit controls microneedle etching - 27-Nov-03 Issue of EDN
At its invention roughly two decades ago, STM (scanning tunneling microscopy]
created a sensation because it was the first technology to make
atomic-scale-resolution imaging a routine procedure. An essential requirement
for the practical application of STM is some means for the reproducible
fabrication of supersharp, atomic-scale needle tips.... [Design Idea by
Stephen Woodward, Marine Sciences, Chapel Hill, NC] |
|
Circuit Controls Multiple Thermoelectric Coolers - 08/19/99 EDN-Design
Ideas Optoelectronic and other components sometimes use a thermoelectric
cooler and a thermistor for temperature control. A typical thermoelectric
cooler....EDN is migrating links. This link is not verified. Search the
"title" EDN for new link. |
|
Circuit controls ratiometric or simultaneous power-up of multiple rails -
13-May-04 Issue of EDN Many applications use FPGAs, ASICs, or DSP chips,
which usually require multiple voltage rails, typically two the core
voltage and the I/O voltage. The core voltage is usually lower than the I/O
voltage. Guidelines for determining how to power up two orvoltage rails depend
on the part and the manufacturer you use.... [Design Idea by Dirk Gehrke,
Texas Instruments, Freising, Germany] |
|
Circuit Controls Slew for Stepper Drive - 03/14/97 EDN-Design Ideas
The circuit in Figure 1 provides slewing control for stepper motors that you
use in sophisticated applications, such as monochromator movements in optical
experiments. The LM331 VFC plays a vital role in this circuit. The constant
10V dc from the IC9596 voltage reference routes to the VFC through the DG303
CMOS switch. The DG303's.... [Design Idea by J Jayapandian, IGCAR, Tamil Nadu,
India] |
|
Circuit Controls Stepper Motors - 01/08/04 EDN-Design Ideas
Stepper motors are useful in many consumer, industrial, and military
applications. Some, such as personal-transportation systems, require precise
speed control. Stepper-motor controllers can be simple (Figure 1], but they
require a variable-frequency square wave for the clock input. The AD9833
low-power DDS (direct-digital-synthesis]IC with....EDN is migrating links.
This link is not verified. Search the "title" + EDN for new link.
|
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Circuit delivers dimming control for white LED driver - 28-Oct-04
Issue of EDN The demand for power in color cell-phone handsets is
constantly increasing. New applications steadily emerge, making it imperative
to reduce power consumption in the design. Examination of usage data shows
thatthan 50% of the power consumed is in providing backlighting for the color
screen. People use the phones for playing games and MP-3s and a multitude of
other heavy-duty, multimedia f.... [Design Idea by Wallace Ly, National
Semiconductor, Santa Clara, CA] |
|
Circuit
Disconnects Load from Battery - 03/14/96 EDN-Design Ideas To
prevent battery damage, the circuit in Figure 1 disconnects the load at a
predetermined level of load voltage. This load voltage, VTRIP, is
closely proportional to the battery voltage. R1 and R2 determine the level of
VTRIP that corresponds to voltage of 1.15V at pin 3 of IC1. A voltage of
1.15V at pin 3 of IC1 causes the internal comparator to trip. Thus, VTRIP=1.15(R1+R2)/R1....
[Design Idea by Michael Keagy, Maxim Integrated Products, Sunnyvale, CA] |
|
Circuit forms DC-mmotor switch with brake - 10-Jan-02 Issue of EDN
Controlling a small dc motor without speed control sounds like a trivial task;
a switch or a relay should suffice. However, several problems accompany this
approach. For one, the switch, because of the inductive load and the low
starting resistance of the motor, tends to wear out prematurely (with all the
related sparks and EMI problems].... [Design Idea by JB Guiot, DCS AG,
Allschwil, Switzerland] |
|
Circuit generates fan-speed control - 21-Mar-02 Issue of EDN
Fan noise is becoming a significant issue as electronic equipment increasingly
enters the office and the home. Noise is proportional to fan speed, and the
airflow¡ªhence, fan speed¡ªnecessary for cooling is less at low ambient
temperatures. Because ambient temperature is lower than the upper design point
most of the time, a fan can run slower, making it easier on the ears....
[Design Idea by Jim Christensen, Maxim Integrated Products, Sunnyvale, CA] |
|
Circuit manages power-up sequencing - 31-Oct-02 Issue of EDN
Power sequencing poses a unique problem in power management. Because improper
sequencing may cause damage to many types of processors, power-up sequencing
of these devices is critical. Devices that may require power-up sequencing
control include FPGAs, ASICs, and DSP chips. These devices can require
tracking I/O and core voltages.... [Design Idea by Martin Galinski, Micrel
Semiconductor, San Jose, CA] |
|
Circuit measures currents in DC servo motor - 6-Dec-01 Issue of EDN
The simple circuit design in Figure 1 lets you measure all components of a
current flowing in a dc servo motor. The rectified output of the circuit uses
ground as a reference, so you can measure the output by using a single-ended
A/D converter. The current-sense resistor, R1, has a value of 0.... [Design
Idea by Shyam Tiwari, Sensors Technology Private Ltd, Gwalior, India] |
|
Circuit precludes common-mode conduction - 4-Feb-10 Issue of EDN
A crossover-control circuit prevents two ortransistors from powering on at
once.... [Design Idea by Ken Herrick, Oakland, CA] |
|
Circuit protects system from overheating - 8-Nov-01 Issue of EDN
The two-chip circuit in Figure 1 provides fan control and overtemperature
warning and shutdown signals to protect systems from excessive heat. The
circuit monitors the temperature of the pc board and the die temperature of a
CPU, an FPGA, or another IC with an on-chip temperature-sensing transistor....
[Design Idea by Kerry Lacanette, Maxim Integrated Products, Sunnyvale, CA] |
|
Circuit Provides Bidirectional Variable Speed Motor-control -
05/16/02 EDN-Design Ideas: During the development of systems
that include small motors, a simple, bidirectional motor controller with speed
adjustment may be helpful. Figure 1 shows such a controller. The circuit uses
everyday components whose tolerances and ratings are unimportant as long as
they sustain the required voltage, current, and power.. / (schematic / circuit
added 11/03] EDN is migrating links. This link is not verified. Search
the "title" EDN for new link. |
|
Circuit provides bidirectional, variable speed motor-control -
16-May-02 Issue of EDN During the development of systems that include
small motors, a simple, bidirectional motor controller with speed adjustment
may be helpful. Figure 1 shows such a controller. The circuit uses everyday
components whose tolerances and ratings are unimportant as long as they
sustain the required voltage, current, and power.... [Design Idea by
Jean-Bernard Guiot, DCS AG, Allschwil, Switzerland] |
|
Circuit provides brownout control of 80C31 - 08/19/99
EDN-Design Ideas In the reset and watchdog-timer circuit in Figure 1,
IC1 is a 74HC14 Schmitt-trigger inverter that, with R1 and C1, acts as an
astable oscillator. The circuit provides an active-high reset for an 80C31 µC.
The watchdog trigger (WDT) consists of watchdog-trigger pulses.... [Design
Idea by N Kannan, Mediatronix, Pappanamcode, India] |
|
Circuit provides Class D motor-control - 1-May-03 Issue of EDN
Class D audio amplifiers provide a dual benefit for battery-powered portable
devices. They enhance battery life, and they produce much less power
dissipation than do their linear cousins. Those features make Class D
amplifiers ideal candidates for controlling speed and direction in small
electric motors.... [Design Idea by John Guy, Maxim Integrated Products,
Sunnyvale, CA] |
|
Circuit provides efficient fan-speed control - 4-Mar-04 Issue of EDN
As Moore's Law plunges us into the realm of multigigahertz processors and PCs
with gigabytes of RAM, engineers face the task of removing the heat that these
state-of-the-art components produce. Cooling such systems poses a dilemma. If
you optimize the fan size and speed for nominal operating conditions, the
system is susceptible to failure when conditions deteriorate.... [Design Idea
by John Guy, Maxim Integrated Products, Sunnyvale, CA] |
|
Circuit provides laser-diode control - 19-Sep-02 Issue of EDN
Laser diodes are sensitive to ESD, rapid turn-on currents, and overvoltage
conditions. To address those problems, the simple laser-diode controller in
Figure 1 has several functions. The first part of the circuit comprises an
8.2V zener diode, D1 that forms the heart of a constant-voltage source for the
laser diode.... [Design Idea by Michael Fisch, Agere Systems, Longmont, CO] |
|
Circuit Provides Motor Feed Control - 07/25/02 EDN-Design Ideas:
Because we needed a small grinding machine, we modified an old milling machine
that lacked a control system. The table of the grinding machine needed only to
move back and forth with adjustable feed. Using an existing dc servoamplifier,
a servo motor, and limit switches, we devised the circuit shown in Figure
1....EDN is migrating links. This link is not verified. Search the
"title" EDN for new link. |
|
Circuits provide 4- to 20-mA PWM control - 09/01/98 EDN-Design Ideas
The circuits in Figure 1 and Figure 3 are useful when you use 4- to
20-mA current-loop signals to control a PWM signal. In both circuits, the
minimum pulse width (corresponding to a 4-mA loop current) and the maximum
pulse width (corresponding to a 20-mA loop current) are independently....File
has many circuits, scroll down.... [Design Idea by Tom Gay, Darmstadt,
Germany] |
|
Clap Activated Remote - (electronic circuit added 10/05)
|
|
CLC030 or CLC031 Control Port Bussed Operation - National
Semiconductor Application Note (app note added 6/06) |
|
Closed Loop FLow Control Manages ATM Channel Bandwidth - 11/21/96
EDN-Design Feature Building Using closed-loop flow control, you can keep
the ATM data pipe wide as well as manage it efficiently. A primer in
closed-loop flow control and the related ICs will help you to implement this
control scheme in your next ATM design.... [Design Feature by David Copeland,
Texas Instruments Inc.] |
|
CMOS Gate Implements Reverse Phase Control - 05/21/98 EDN-Design
Ideas The circuit in Figure 1 implements a "reverse" phase control,
using only a single CMOS 4001 quad NOR gate. The circuit is known as a reverse
phase control because, unlike with common triac or SCR controls, conduction
begins at the zero crossing of the ac sine wave. Timing of the turn-off
point....File has seeveral circuits, scroll down.... [Design Idea by JC
Johnson, Lithonia Lighting, Decatur, GA] |
|
CMOS NAND gates control sump pump - 14-May-09 Issue of EDN A
similar circuit lets you control both the sump pump and the water level....
[Design Idea by V Gopalakrishnan, Indira Gandhi Center for Atomic Research,
Kalpakkam, India] |
|
CMOS Toggle Flip Flop Using Push Button - The circuit below uses a
CMOS dual D flip flop (CD4013) to toggle a relay or other load with a
momentary push button. Several push buttons can be wired in parallel to
control the relay from multiple locations. A high level from the push button
is coupled to the set line through a small (0.1uF) capacitor. The high level
from the Q output... [Bill Bowden's site] |
|
CNC Router Now this was an interesting project. |
|
CO2 Controller for planted tanks - (schematic / circuit added 10/02)
|
|
Combination Controlled Fully Customizable RF Remote Control -
(schematic / Circuit design added 08/05) |
| Comparator Adds
Current Limit to V2 Controller - 0521/98 EDN-Design Ideas Many
step-down controllers satisfy the need for generating low voltages for µPs and
logic. The lower the output voltage, the greater the importance of building a
system with fast transient response. Some new controllers use the V2 control
architecture, which provides several speed improvements over….contains
multiple circuits scroll to find this circuit.... [Design Idea by Dimitry
Goder, Switch Power Inc, Campbell, CA] |
|
Comparator Controlled H-Bridge Circuits (LM311) - Circut three and
four are simple Bi-Polar H-Bridge circuits. The bridges are controlled by a
pair of LM311 voltage Comparators. The LM311 Voltage Comparator has several
unique features, one of which is an output transistor with an open emitter as
well as the typical open collector. This allows the output transistor of
the comparator to sit between the bases of the power transistors. The
LM311 Voltage Comparator also has a STROBE input that will turn off the output
regardless of input conditions. The circuit is shown in two
configurations. The first is a typical two input bridge. The second circuit
has a single - duplex input that would be used for model railroad "DCC"
control applications.... This page has several circuits....please scroll
down to these.... [from Rob Paisley's Model Train web site] |
|
Component Video Filtering Using the ML6420/ML6421/ AN-42035 -
Fairchild Application Notes / (app note added 6/06) |
|
Computer Controlled Model Train Set - (circuit / schematic design
added 6/06) |
|
Computerized Infrared Remote - control your stereo, TV and VCR from
Windows, includes schematic and software (added 4/02) |
|
Configuring the AD7877 - AN-753 Analog Devices Application Notes
(app note added 2/06) |
|
Constant Temperature Circuit - This circuit is a generic low power
temperature controller that can be used for stabilizing temperature sensitive
electronic circuits. It was built to stabilize a radio frequency VFO (Variable
Frequency Oscillator) for ham radio applications. The circuit has also been
used to lower the drift of a Ramsey FM10a micropower FM
transmitter....(schematic / Circuit design added 9/02) [G. Forrest Cook] |
|
Consumer STB/DVD - (application / block diagram added 6/07)
|
|
Continuity Tester - This
circuit senses only dead shorts on a populated board. It will not ring
through or damage components. It shuts off when Continuity Tester - not
in use. It was first published in Electronics Magazine June 21, 1979,
page 145. [Designed by Andrew R. Morris] |
|
Continuity Tester - This circuit will detect low resistances and
high resistances to produce a tone from the speaker. It will detect up
to 200k and the circuit automatically turns off when the probes are not used.
|
|
Continuity Tester - Starting with a 9 volt supply, when the probes
are shortcircuited there is a 8.2 volt drop across the zener diode Z1 leaving
a maximum of 0.8 volt across R1. Application of Ohms' Law
showse....(circuit added 04/05/06) [Tony van Roon's circuit] |
|
Continuity Tester - This is another invaluable piece of test
equipment for digital work. It has been designed by us to cater for a
particular application….(electronic circuit added 05/06) [G. Forrest Cook] |
|
Control 120VAC relay with TTL - ASCII format (Circuit design added
7/06) |
|
Control 32 DAC channels via a parallel port - 12/31/69 EDN-Design
Ideas Occasionally, a system needs several digitally programmable
voltage-output channels. Such output channels typically provide the control
for robot positioning, industrial processes, and even home automation. The
circuit in Figure 1 controls 32 voltage-output channels from the parallel port
of a PC....[File contains multiple circuits. Scroll to find this
one.].... [Design Idea by Mark A Shill, Burr-Brown Corp, Tucson, AZ] |
|
Control a processor's power supply in real time - 31-Mar-05 Issue of
EDN Dynamic control of processor's supply rail minimizes power
consumption.... [Design Idea by Yogesh Sharma, Analog Devices, San Jose, CA;
Edited by Brad Thompson] |
|
Control Applications of CMOS DACs - National Semiconductor
Application Note (app note added 6/06) |
|
Control Electrical Appliances using PC - Here is a circuit for using
the printer port of a PC, for control application using software and some
interface hardware. The interface circuit along with the given software can be
used with the printer port of any PC for controlling up to eight equipment .
The interface circuit shown in the figure is drawn for only one device, being
controlled by D0 bit at pin 2.... (added 04/05/06) |
|
Control Mains Powered Devices with Low Voltage - Switch mains
powered devices on and off safely and simply with low voltages…. [REUK -
Renewable Energy UK website] |
|
Control stepping Motor via USB interface - This is an example that
demonstration how to control some devices via USB interface.The PC software
program with delphi. Feature:, CPU PIC18F4550 with full speed USB interface at
48MHz., USB 2.0 compliance, Use on-chip USB driver....(schematic added 7/08)
|
|
Controller Easily Evaluates 2 Bit Gray Code - 06/19/97 EDN-Design
Ideas....EDN is migrating links. This link is not verified. Search the
"title" EDN for new link. |
|
Controller for rotary film processor - If you want to develop your
color film, and specially slides, at home, here is the machine you need!
[Manfred Mornhinweg] |
|
Controller IC and one-shot form resonant controller - 28-Nov-02
Issue of EDN Resonant power supplies are popular because of high
efficiency, low noise, and compactness. You can implement a resonant buck or
boost converter using a single switch. The regulation of the output in such a
converter derives from using a constant on or off time and a variable
frequency. The UC1864 controller IC (Texas Instruments, www.... [Design Idea
by C Rajan, Centre for Advanced Technology, Indore, India] |
|
Controller Provides Closed Loop Temperature Regulation - 05/08/97
EDN-Design Ideas EDN is migrating links. This link is not
verified. Google the "title" EDN for new link. |
|
Controller Provides Constant Power DC Load - 03/14/96 EDN-Design
Ideas EDN is migrating links. This link is not verified.
Google the "title" EDN for new link. |
|
Controller provides multiple alarm-driver formats - 15-Jan-98 Issue
of EDN Using a piezoelectric element for alarm applications offers low
cost, low power, and flexibility. By coupling this element with a 12C508
programmable controller (Microchip Technology, Chandler, AZ], you can
implement an eight-pin alarm generator. This approach provides multiple
driver formats with a minimum of additional cost and footprin.... [Design Idea
by William Grill, Riverhead Systems, Littleton, CO] |
|
Controller Supports Differential Monitor Display - 06/24/99
EDN-Design Ideas You can assemble a differential monitoring display
using rail-to-rail analog hardware and a 12C671 eight-pin controller
(Microchip Technology, www.microchip.com) (Figure 1). The controller, IC1,
[Design Idea by William Grill, Riverhead Systems, Littleton, CO] |
|
Controlling 3-Phase AC Induction Motors using the PIC18F4431 -
Microchip Application Note Published 29-Jun-04 (app note added 2/06)
|
|
Controlling a Light with Two Switches - a light or lights can be
controlled by more than1-switch (added 5/03) |
|
Controlling a Variable Voltage Power Supply using the DS1809 Pushbutton
Control - Maxim Application Note #1035 (app note added 5/08)
|
|
Controlling Relays with Logic Voltages - (circuit / schematic added
5/03) |
|
Controlling slew times tames EMI in offline supplies - 14-Nov-02
Issue of EDN EMI from offline switching power supplies typically causes
all sorts of problems for power-supply designers. You may need a large EMI
filter to meet FCC emission requirements. Switchers for high efficiency
produce high-frequency switching noise that can propagate through the rest of
the system and cause problems.... [Design Idea by David Canny, Linear
Technology Corp, Milpitas, CA] |
|
Controlling TDMA Timeslot Power Levels using the Esg-D Series, RF Signal
Generators - Aligent Application Note (added 6/06)
|
|
Convert Digital Mains Timer To Low Voltage - Convert a cheap digital
mains timer into a low voltage programmable timer relay…. [REUK - Renewable
Energy UK website] |
|
Cooling Fan Controller - As we begin to enjoy those lazy hazy days
of summer, the most important thing on most of our minds is how to keep cool
during those hot days. For some of us that means turning up the old air
conditioner and sipping on a nice cold glass of our favorite soft drink.
However, we often forget about an equally important.... [Radio Amateur
Society of Norwich] |
|
Correct voltage drop and phase shift in transmission lines -
20-Mar-03 Issue of EDN Many precision test-and-measurement and
high-speed analog applications require an exact targeted voltage to be
delivered to the device under test or intended load to accurately analyze the
device. Design and test engineers are well-aware that this goal is sometimes
unattainable, because the impedance across the traces delivering the signal to
the load alters the original signal.... [Design Idea by Ron Shakery, Texas
Instruments, Dallas, TX] |
|
Courtesy Light - 15 seconds delayed switch-off for220-Volt AC lamp,
a good idea for bedroom lamps (added 11/06) |
