$5 junkbox Circuit Determines Phase Sequence :
04/23/98 EDN-Design Ideas |
4 to 20 mloop needs no external power source:
09/13/2001 EDN - Design Ideas / The simple circuit
in Figure 1 uses a low-current-drain MAX4073H
amplifier to sense the current flowing through a 4-
to 20-mA loop. The circuit senses the current
through a 1O resistor with a fixed gain of 100 and
uses no battery or dc power supply. The low current
drain of the amplifier (0. . |
|
48 input�16 output crosspoint IC eliminates the need
for multiplexer amps: 02/20/03 EDN-Design Ideas
/ Crosspoint switches are ideal for use in
video-security systems, which accept multiple camera
inputs while providing playback and multiple
loop-through to multiple monitors. To provide video
loop-through or monitor outputs, these systems often
require additional multiplexer amplifiers that can
drive standard video loads... |
Analog Encoding: Convert switches and sensors
into DMX signals. Uses are found in Haunted houses,
stage plays, themed events, holiday light
animations, anytime you want to control DMX
compatible equipment. Fog machines and strobe lights
can be independly controlled be remote switches or
sensors. |
Audio Signal Source: |
Autoreferencing circuit nulls out sensor errors:
01/24/2002 EDN - Design Ideas / The autoreferencing
circuit in Figure 1 nulls out the error of a sensor,
such as a pressure transducer, at its reference
level-for example, at ambient pressure. The circuit
is an analog-digital-feedback control system that
uses a digitally programmable potentiometer to
provide the variability. . |
CEMF (counterelectromotive Force) Charger: The
CEMF charger uses the CEMF (counterelectromotive
force) from an inductor to charge a capacitor to
high voltages from a low voltage source.
|
Circuit avoids metastability: 08/30/2001 EDN -
Design Ideas / Consider a computer system that has a
host processor connected to a remote-I/O subsystem
(Figure 1). The host clock treats the I/O system,
which is located far from the main hardware, as a
slave. Because of the transmitters, receivers,
remote-system logic, and cable length, the data the
host receives has a dramatic latency. |
Circuit Disconnects Load From Lowvoltage Supply:
04/24/03 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit |
Circuit Forms gammaphoton Detector: 04/24/03 EDN-Design
Ideas / PDF contains multiple circuits - scroll to
find this circuit |
Circuit gang programs EEPROMs over I 2 C bus:
09/13/2001 EDN - Design Ideas / You use the fully
controlled circuit in Figure 1 to parallel-program
two-wire serial EEPROMs via the I2C bus. Gang
programmers must address all memory devices during a
write operation. To verify the memory contents,
however, the system must address only one memory at
a time during read operations. . |
Circuit improves further on first event detector:
06/27/2002 EDN - Design Ideas / The circuits in
Figure 1have certain advantages over those in a
previous Design Idea (Reference 1). The first-event
detector with autoreset (Figure 1a) consists of N
sets of monostable multivibrators, using 4001 logic
circuits with LEDs attached. After any player (1
through N) presses a pushbutton, the corresponding
monostable multivibrator switches on, and its
associated LED |
Circuit produces variable frequency, duty cycle:
07/24/03 EDN-Design Ideas / This Design Idea
shows a simple, low-cost circuit that produces a
highly accurate variable-frequency and
variable-duty-cycle output (Figure 1). Further, the
duty cycle and frequency are independent of each
other (excluding 0 and 100% duty cycle). The method
derives its accuracy and stability from the fact
that the output is based on a crystal oscillator and
divisions of the oscillator's frequency.... |
Circuit provides leading edge blanking:
05/29/03 EDN-Design Ideas / In isolated switch-mode
power supplies using peak-current-mode control,
generally the current-sense resistor senses the
current on the primary side of the power converter.
Figure 1 shows a typical circuit, in which R2 is the
current-sense resistor that monitors the current.
The current-sense signal goes to the input of the
PWM comparator—in this case, the PWM comparator's
input (ISENS..... |
Circuit translates I 2 C voltages: 12/26/2002
EDN - Design Ideas / This Design Idea explores
level-shifting an I�C bus from 5V/ground (positive
domain) to ground/25V (negative domain). In
multisupply systems, you sometimes face a situation
in which digital information stored in logic
circuits running from 5V to ground needs conversion
to analog signals referenced to a negative supply.. |
COCKCROFT and WALTON VOLTAGE MULTIPLIERS: Here
are some applications of the Cockroft-Walton voltage
doubler circuit for generating high voltages from a
low voltage AC source. The circuit is quite
practical for generating thousands of volts (or
more) or just a few volts at high current.
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Combinational Conjuring Trick:
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Conjuring Trick: |
Consider The "Deboo" Integrator for Unipolar
Noninverting Designs : 03/18/02 Electronic
Design - Ideas for Design / The design of a standard
inverting integrator is simple when bipolar supplies
are available, but it's cumbersome with a unipolar
supply. To allow adequate headroom for the output,
the circuit must be biased away from ground, often
at half the supply... |
Converter ignores Power Supply Variations:
01/05/95 EDN-Design Ideas |
DEER REPELLENT: Here is a simple sensor, which
can detect the seismic vibrations caused by a person
or large animal walking nearby. A representative
application for the sensor is a deer repellent for
the vegetable garden. When a deer steps near the
sensor a loud buzzer or beeper sounds for a few
seconds startling the would-be vegetable thief away.
|
Deer Repellent: seismic sensor
|
Diodes improve inverter Efficiency: 04/29/99 EDN-Design
Ideas / PDF contains multiple circuits - scroll to
find this circuit |
Door/Window Sensor Resists Tampering: 01/21/99
EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit |
Doorbell for the Deaf: |
Ease Capacitor ESL/ESR Measurement With
MercuryWetted Relay : 11/25/02 Electronic Design
- Ideas for Design / Capacitor discharge circuits
are used extensively in fast pulse generation. In
such applications, the capacitor's stray inductance
(or equivalent series inductance) and series
resistance play an important role in determining
performance of the... |
Electric Discharge Tubes: |
Electromagnetic Field Detector: This circuit is
sensitive to low frequency electromagnetic radiation
and will detect for example hidden wiring or the
field that encompasses a transformer. Pickup is by a
radial type inductor, used as a probe which responds
well to low frequency changing magnetic and electric
fields. Ordinary headphones are used to for
detection. The field that surrounds a transformer is
heard as a 50 or 60Hz buzz. |
Electronic Coin tosser: |
Electronic fish lure : |
Electronic Fish Lure: |
Electronic Jam: |
Electronic 'snap': First Response Monitor |
Fast Compact Routine Interfaces EEPROM to �C :
03/04/99 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit. |
Flash Memory Anticipates Architecture Transformation:
02/20/03 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit |
Foreign Vocabulator Recollector: It was designed
especially to learn German and Russian words, in a
random multiple-choice format. |
Frequency Dependant Negative Resistor (Using OpAmps):
|
Frequency source feeds entire lab: 01/23/03 EDN-Design
Ideas / Plumbing a laboratory with a standard
frequency makes a lot of sense if the lab uses
multiple frequency counters, spectrum analyzers, and
other frequency-dependent test equipment. Rather
than spending time keeping all of the instruments'
oscillators in calibration or buying expensive,
high-precision oscillators, you can use the circuit
in Figure 1 to distribute a single calibrated
frequency sou..... |
FUN CIRCUITS: This pdf document consist of 5
individual circuits to have fun with some of the
titles include smell a vision, the dripper and
remote control blocker well worth a look.
|
Gag Circuits: magic lamp, dripper (improved!,
remote control jammer |
Get more power with a boosted triode: 04/03/03
EDN-Design Ideas / Even though 6L6 beam-power tubes
have been around for 66 years, they are still quite
popular for use in electric-guitar amplifiers, and
its cousin, the 6CA7 (EL34) power pentode, is a
favorite among audiophiles. The developers of these
tubes designed them for pentode-mode operation, and
they deliver maximum audio power in this mode... |
Get more power with a boosted triode: 06/12/03
EDN-Design Ideas / This Design Idea is a reprint of
an earlier one that contained errors in graphics
(Reference 1). Even though 6L6 beam-power tubes have
been around for 66 years, they are still quite
popular for use in electric-guitar amplifiers, and
its cousin, the 6CA7 (EL34) power pentode, is a
favorite among audiophiles... |
Hardware Accelerator Targets Cosimulation:
02/20/03 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit |
HeNe & Solid State Laser Power Supplies & Notes
(similar to Above): |
Hierarchical Priority Encoder:
|
High side driver has fault protection:
09/05/2002 EDN - Design Ideas / High-side drivers
find common use in driving grounded solenoid coils
and other loads. Short-circuit protection for such
drivers is essential for avoiding damage from wiring
faults and other causes. Polymer fuses are generally
too slow, and discrete current-limiting circuits are
large and cumbersome. The circuit in Figure 1 uses a
small, low-dropout linear regulator as a high-side
switch and p.... |
Hot Swap Structure offers Improved Redundancy:
01/09/03 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit -- 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.
|
Hot Water Tank Indicator: |
IC maintains uniform bias for GaAs MESFETs:
08/22/2002 EDN - Design Ideas / The gate-turn-on
threshold voltage for GaAs MESFETs (gallium-arsenide
metal-semiconductor field-effect transistors) varies
considerably from part to part, even within a given
lot. That behavior makes biasing difficult,
especially if you want to design the device into a
high-volume product. To overcome this drawback, you
can introduce a current sensor that monitors the
bias current and provides .... |
InductanceSubstitution Circuit Uses Variable Coils
: 01/07/02 Electronic Design - Ideas for Design
/ When prototyping RF circuits, computer simulation
or de-sign programs can potentially yield the wrong
component values. These errors are caused by the
omission of capacitances or inductances originating
from the board layout or other considerations.... |
Inexpensive XRay Machine #1:
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Invisible Broken Wire Detector:
|
Jacob's Ladder, How to Make One :
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Jacob's Ladder: |
Laser Communication System: This is a simple
Laser communication system. It can transmit and
receive signal from any audio device.Communication
distance is few meters. All components are not
critical. Transistor 2N2222 may be on the coolrib.
Laser diode is from laser pointer
|
Laser Printer Prototypes PC Board Artwork:
05/12/94 EDN-Design Ideas
|
LC Filter Design: |
LED Torch: |
Lightening Detector: |
Magic Lamp: Old idea, newtwist.
|
Magic Wand: |
Magnetic Gun: When optimally tuned, it will
propel a small slug about 1.5 metres high, or 2.5
metres horizontally |
Magnetic Levitation Circuit:
|
Mega phone circuit 9v: |
Multilayer capacitor doubles as varactor:
03/20/03 EDN-Design Ideas / The main purpose for
building the circuit in Figure 1 is to study the
idiosyncrasies of X5R, Z5U, and Y5V multilayer
ceramic capacitors. The circuit is also an
inexpensive VCO (voltage-controlled oscillator) with
only five components. Many types of ceramic
capacitors for surface-mount placement are on the
market... |
Negative Resistance Increases inductor's Q:
03/30/95 EDN-Design Ideas |
NEGATIVE SUPPLY FROM SINGLE POSITIVE SUPPLY: Op
amps are very useful. But one of their major
drawbacks is the requirement of a dual supply. This
circuit solves the problem to a certain extent. It
provides a negative voltage from a single positive
supply. |
Neon Desk Lamp: |
PC Board Layout Eases High Speed Transmission:
11/08/01 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit
|
Pedometer: |
Perimeter Monitor: Using a single cable such as
speaker wire or doorbell cable, this circuit can be
remotely positioned, for example, at the bottom of a
garden or garage, and used to detect all sound in
that area. The cable can be buried in a hosepipe or
duct and is concealed out of sight. The mic is an
ordinary dynamic mic insert and should be housed in
a waterproof enclosure with the rest of the circuit.
|
Portable CD Player Kit: The hardware consists of
a normal tape cassette fitted with a stereo cassette
head. The heads signals are provided by a standard
CD player. The power supply consists of an
adjustable regulator connected to the cars cigarette
lighter connector. |
Pot Plant Power: All plants carry an electric
charge relative to the ground. This charge is more
or less constant regardless of the size of the plant
- a kind of background voltage" in nature. This
electric charge suffuses the entire plant, from its
roots to its leaves and fruit. It was measured
between a chrome-plated pin inserted into the plant
(the positive terminal) and an iron spike driven
into the ground (the negative terminal).
|
Power circuit terminates DDR DRAMs: 11/14/2002
EDN - Design Ideas / DDR (double-data-rate) SDRAMs
find use in high-speed memory systems in
workstations and servers. The memory ICs operate
with 1.8 or 2.5V supply voltages and require a
reference voltage equal to half the supply voltage (VREF=VDD/2).
In addition, the logic outputs terminate with a
resistor to the termination voltage, VTT, which
equals and tracks VREF.. |
PreWarped Drive Signal Reduces Actuator Hysteresis
Error : 02/18/02 Electronic Design - Ideas for
Design / Many displacement transducers exhibit
hysteresis in their response to drive signals. To
observe this behavior, drive the actuator with a
triangle wave while measuring the actuator response
with a linear position transducer. Then, display the
command... |
Quiz Game Circuit: |
Refrigerator Door Alarm: |
RISC �P implements fast FIR filter: 01/21/99 EDN-Design
Ideas / PDF contains multiple circuits - scroll to
find this circuit
|
Routine automates pattern/sequence detection:
05/16/2002 EDN - Design Ideas / Sequence detection
is a common operation in many communication and
security systems. Some good examples are HDLC-flag
identification and signature analysis. As the
complexity of the system increases, designing
circuitry for sequence detection becomes tedious and
laborious. Using the software tool in this Design
Idea, you can generate HDL code in VHDL or Verilog
formats for both Mealy and Moore .... |
Routine yields fast bit reversing for DSP algorithms:
09/13/2001 EDN - Design Ideas / If you need
efficient real-time performance in DSP applications,
you need an efficient bit-reversing routine. For
several FFT programs, data permutation can take 10
to 50% of the computation time, depending on the
input-data dimensions and length. The idea behind
bit reversing is to shuffle the data by flipping the
address bits around the middle of the address length
so that if the data l... . |
RTTY Terminal unit: |
Rules of thumb Aid in timeconstant Analysis:
11/06/97 EDN-Design Ideas |
Several Nuclear Physics Related Circuits:
|
Simple FIFO provides data width conversion:
09/26/2002 EDN - Design Ideas / Many designs
require FIFO elastic buffers to form a bridge
between subsystems with different clock rates and
access requirements. However, in some applications,
you need FIFO buffers for data conversion. One
example is the case in which you need t |
Simple PIC16F84 Programmer: |
Simple Technique Generates Precise HART Waveforms
: 07/22/02 Electronic Design - Ideas for Design
/ Designed to complement conventional 4- to
20-mA analog signaling, the Highway Addressable
Remote Transducer (HART) protocol supports two-way
digital communications for process measurement and
control devices. The protocol uses frequency-shift
keying... |
Single Phase Electronic Starter:
|
Singlesideband Demodulator Covers the HF Band:
10/26/00 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit |
Solar Cell Nicad Charger: |
Soldering Technique Reduces PC Board Damage:
05/21/98 EDN-Design Ideas |
Spectrum Analyzer & Equalizer Designs: for audio
frequencies, article first appeared in the
February1982 issue of Recording-engineer/producer
magazine |
Speller Effect Sign Display:
|
SSB AF Filter: |
StateVariable Oscillator Suits Ratiometric
Capacitive Sensors : 09/30/02 Electronic Design
- Ideas for Design / Often, it's necessary for a
sensor system to compute the ratio of two
capacitors. Doing so re-duces the transducer's
sensitivity to dielectric errors from such factors
as temperature. Furthermore, dual sensors are
typically used to double the... |
Static Electricity / Negative Ion Detector: This
circuit relies upon the extra high input impedance
of a FET, and also demonstrates the gate terminals
sensitivity to changes in voltage. |
Stud Sensor Automatic : |
Supply uses AC to Generate 5V, Power on Reset :
05/16/2002 EDN - Design Ideas / 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 |
T Volt Remote Control Blocker: this PDF file
includes also some other funny circuits |
Tandem hookups Enhance utility of DC / DC units:
01/02/97 EDN-Design Ideas |
Tele Scope: |
Temperature Monitor: |
Transconductance amp gives oscillator reciprocal
response: 04/17/03 EDN-Design Ideas / The
circuit in Figure 1 is a variation on the familiar
integrator/comparator triangle-wave oscillator,
which you typically implement with two op amps. An
integrator and a comparator connect in a
positive-feedback loop; the comparator drives the
integrator and vice versa. A fixed amount of
hysteresis exists in the comparator, producing a
triangle wave at the integrator's output... |
Ultrasonic Dog Whistle: |
Voice Storage Chips Talk to Each other: 11/05/98
EDN-Design Ideas |
Whistle Detector: It uses digital techniques to
measure and decode the input signal to detect a
whistle, all using a 8-pin PIC device and a handful
of analog components. This project is ideal for
beginners wanting to try their hand a PIC
programming! |