1.2GHz Frequency Counter: |
1.5 AMP Shunt Ammeter Circuit: circuit converts a 0-15Volt
voltmeter to a 1.5Amp ammeter |
12 Volt Battery Capacity Tester: This circuits makes the
amp-hour test simple and cheap. The amp-hour reading obtained
should be accurate to within10% if the load resistor (lamp) is
properly calibrated. |
|
120 MHz Frequency Counter: |
16 Bit AD Converter W / RS232 Interface:
|
2 Tone Audio Oscillator (use for SSB Tests):
|
220 Volt Live Wire in Wall Scanner 2: |
220 Volt Live Wire in Wall Scanner: This circuit senses
power lines behind walls |
220 Volt Wiring Detector: |
25 k Volt Generator Tests Insulation: 06/04/98 EDN-Design
Ideas |
3 Channel Spectrum Analyzer: This3 channel15 LED spectrum
analyzer can be used as an addition to any audio amp project. It
produces fantastic displays on3-LED bars that can be
individually adjusted for any particular frequency range. |
4 Channel DSO for oscilloscope: |
50 MHz Frequency Counter, Voltage Meter & SWR / PWR Indicator:
|
50 MHz Frequency Counter, Voltage Meter & SWR/PWR indicator:
|
555 Go / No Go Tester: |
555 Timer IC Tester: |
741 Based Light Sensor: CdS photocell used for light/dark
controlled relay |
AC Line Current Detector: |
AC Millivoltmeter: |
AC/DC LED Indicator: |
Accelerometer Schematic: |
AdjuStable Continuity Tester: |
Adjustment Free Inclinometer operates on 2.7V: 04/24/97 EDN-Design
Ideas |
ADXL202 Accelerometer to C Volt Output: The Air Whammy is a
simple dual control voltage generator that uses a 2 axis
accellerometer as the source. The whole circuit fits into
a small project box (approximately 65x40mm), and is powered from
a 12V AC plugpack. |
Air Pressure: Circuit uses a NPP301 pressure sensor. Range
of this sensor is1bar (15psi). It will output40mV at normal air
pressure and3x overload doesnt damage the device.
|
Altimeter: |
Analog input circuit serves any microcontroller: 12/20/2001
EDN - Design Ideas / The simple ADC in Figure 1 is perfect for
getting analog signals into a purely digital microcontroller.
Using just five surface-mount parts, you can assemble it for
less than 50 cents (1000), which is approximately half the cost
of a single-chip-ADC approach in the same volume. Moreover, this
design takes only one pin from the microcontroller to operate. . |
Analog
LED Bar VU Meter: built around discrete components |
Arbitrary Waveform Generator: |
Audible Circuit Tracer: |
Audible Continuity Tester: |
Audio Frequency Meter: |
Audio
LED VU Meter: built around discrete components
|
Audio MilliVoltmeter: |
Audio Test Oscillator: |
Audio test Station: |
Battery Equal Charge Indicator: |
Battery Pack Discharger: |
Battery Tester for 1.5 & 9V: |
Beeper to Find Short Circuits: |
Build a Magnetic Field Immunity Tester: |
Build your own bypass capacitor tester: 12/06/2001 EDN -
Design Ideas / Most circuits use bypass capacitors and can
deliver substandard performance if the capacitors have poor
pulse characteristics. Few if any articles cover how to test
bypass capacitors for pulse characteristics. The circuit in
Figure 1 tests these characteristics. It charges the capacitor
under test through 100 kU for approximately 1 msec and then
discharges it through 10U for a... . |
Cable Tester is Fast & Cheap: 09/24/98 EDN-Design Ideas
|
Calibrate scope jitter using a transmission line loop:
09/20/2001 EDN - Design Ideas / Digital-clock-period jitter is
the variation in the period of a clock cycle compared with a
nominal (average of many cycles) clock period. To accurately
measure period jitter using an oscilloscope, you must subtract
the oscilloscope jitter fro. |
Calibration Technique uses Sound: 09/01/98 EDN-Design Ideas
|
Capacitance Meter: |
Cell Cycler Sorting Sires Superior Batteries: 06/23/94 EDN-Design
Ideas |
Circuit Adapts Signals for Visual Perception: 10/12/95 EDN-Design
Ideas |
Circuit measures currents in dc servo motor: 12/06/2001 EDN
- Design Ideas / 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. . |
Circuit Measures Small Currents Referenced to High Voltage Rails:
01/07/02 EDN-Design Ideas / / PDF contains multiple circuits -
scroll to find this circuit |
Circuit Monitors Multiple Contact Closures: 02/15/96 EDN-Design
Ideas |
Circuit Monitors Pump On/Off Times To Ensure Safe Operation
: Electronic Design - Ideas for Design / In a septic-tank-based
sewage system, waste water and toilet wastes from, say, a
residence drain into the first compartment of a two-compartment
septic tank. A grating between the compartments allows just
liquid waste to drain into the second... |
Circuit Provides Accurate RTD Measurements: 04/12/01 EDN-Design
Ideas / PDF contains multiple circuits - scroll to find this
circuit. |
Circuit Tests Power Outage Susceptibility: 03/03/97 EDN-Design
Ideas |
Circuitry for inexpensive Relative Humidity Measurement:
National Semiconductor Application Notes,04-Nov-1995 |
Connection Tester: |
Constant Voltage Load Tests Battery Chargers: 04/11/96 EDN-Design
Ideas |
Construction of Low Resistance Shunts: |
Continuity Tester, Latching: Awesome tester!- at least in
the designers opinion! |
Continuity Tester, Smart: |
Continuity Tester: |
Convert your DMM to a pH meter: 10/17/2002 EDN - Design
Ideas / It's often necessary to know the acidity of a solution
to control a process. Even inexpensive pH meters can be
relatively costly, and many of the inexpensive models have no
output that you can readily connect to a computer interface. A
simple solution to this problem is to attach a pH probe to a
high-impedance input of an op amp and read the output with a
digital voltmeter (Figure 1).. |
Create your Own Meter: |
Curious C Beeper: |
Current Sense Amplifier Handles High Voltages: 11/06/97 EDN-Design
Ideas |
Current Sense IC Prevents Overcurrent Damage: 04/25/96 EDN-Design
Ideas |
Cut Phone Line Detector #1: Can be used to alarm security
system |
DC Millivolt Meter: |
Deflection Amplifier for oscilloscopes: |
Delay Simulator Debugs Communications Equipment: 10/27/95
EDN-Design Ideas |
Design makes handy audible circuit tracer: 01/09/03 EDN-Design
Ideas / The circuit tracer in Figure 1 is a handy tool for
finding connectivity paths on a pc board. Because the sense
voltage you use to measure the path is lower than a transistor's
VBE voltage, you can use the design in circuits containing
semiconductor elements without affecting the measurement. The
tracer's output takes the form of audio tones |
Differential Scope Probe Delivers 6GHz Bandwidth to the Screen:
02/20/03 EDN-Design Ideas / PDF contains multiple circuits
- scroll to find this circuit |
Digital / Standard Phone Line Tester: make sure that the
line is suitable for modem use and your PCMCIA does not damage
if you plug it in |
Digital Frequency Counter: |
Digital PC Oscilloscope: |
Digital Pressure Gauge: |
Digital Volt Meter With Video Output: |
Digital Volt Meter: |
DIGITAL VOLTMETER: This is just a schematic view of a
digital voltmeter all components and values are listed.
|
Diode & LED Tester: |
Dip Oscillator for HF: |
Distortion Analyzer: |
Distortion Measurement Circuit: |
DMM Measures Light Level #1: 07/04/94 EDN-Design Ideas
|
DMM Measures Light Level #2: 08/15/96 EDN-Design Ideas
|
DSPbased Wireless Analyzer Targets 2.5 and 3G Networks:
02/20/03 EDN-Design Ideas / PDF contains multiple circuits
- scroll to find this circuit |
Electric Field & Leakage Detector: |
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 a50 or 60Hz
buzz. |
Electromagnetic Field Probe With Meter: |
Electronic Construction Level: |
Electroscope: |
Eliminate thermoelectric EMF in low ohm measurements:
06/13/2002 EDN - Design Ideas / When two different-metal
conductors connect together in a loop and one of the junctions
is at a higher temperature than the other, an electrical current
flows through the loop. The magnitude of this current depends on
the type of metals involved and the temperature differential of
the junctions. When you open such a loop, a thermoelectric
voltage appears across the open ends.. |
EMF Field Probe: |
ESD Gun : |
ESR Meter: |
Ethernet 10Base T Simulator Jig yields Zero Emissions:
10/22/98 EDN-Design Ideas |
Expanded scale indicator revisited: 08/08/2002 EDN - Design
Ideas / The visualization aid that a previous Design Idea
describes allows only the expansion of the upper end of the
scale (Reference 1). But what can you do if, according to your
project requirements, you need to expand the middle region of
the scale? Figure 1a illustrates the challenge. A voltmeter
comprises a 100-�A dc meter and a series resistor |
Expanded Scale Voltmeter uses Just Two Parts: 01/20/1994 EDN
Design Ideas / The expanded voltmeter doesnt require trimpots to
obtain usable accuracy or require the tedious selection of Zener
diodes. This circuit consists of only two parts and a5V meter.
The circuit is completely linear and requires no calibration
except the rare mechanical zeroing of the meter. By using a
split voltage reference system with floating output, the zero
point of the voltage supplied to the meter equals the absolute
sum of the two references. |
Femto
Capacitance Meter: This meter measures into the low
femtofarad area. Measuring in the femto area allows the smallest
capacitors to be measured with precision. Such capacitors are
commonly used to compensate for input and stray capacitance in
amplifiers. |
Field Strength Meter #1: |
Field Strength Meter #2: |
Field Strength Meter #3: |
Fluxmeter to DVM input: |
Four Channel Oscilloscope Adapter: |
Frequency & Capacitance Meter: |
Frequency Comparator Draws 8 �A: 03/03/97 EDN-Design Ideas |
Frequency Comparator has Status Output: 12/26/02 EDN-Design
Ideas / The original application for the circuit was to check
the number of revolutions of an engine with only one LED as an
indicator. The measurement of the number of revolutions usually
involves sensors with a frequency output proportional to the
number of revolutions. |
Frequency Comparator: |
Frequency Counter Module: |
Frequency Doubler operates on Triangle Waves: 09/29/94 EDN-Design
Ideas |
Frequency Measurements using PC: |
Frequency Window Comparator has hysteresis: 11/07/96 EDN-Design
Ideas |
Full Featured Transistor Tester: |
Function Generator: |
Function Generator: |
Grid Dip Meter: |
High / Low indicator: |
High Side Current Sensor has Period Output #2: Maxim APP
1084: May 31, 2002 |
High side current sensor has period output: 03/07/2002 EDN
- Design Ideas / You use high-side current monitoring in many
battery-powered products that require accurate monitoring of
load current, charger current, or both. In applications for
nonportable designs, high-side-current monitoring serves as a
power-supply watchdog that can flag a failure in downstream
devices. . |
High side current sensor monitors negative rail: 04/17/03
EDN-Design Ideas / All dedicated current-sense amplifiers
provide high-side sensing on a positive supply, but you can
adapt such circuits for monitoring a negative supply (Figure 1).
The positive-supply pin, V+, connects to the system's positive
supply, and the ground pin, GND, connects to the negative
supply, VEE. That arrangement monitors the negative supply and
provides a positive output voltage for the extern.. |
HighVoltage Monitor Features High Accuracy : 08/1902
Electronic Design - Ideas for Design / Many applications call
for measuring ac lines or high dc voltages. One common technique
uses a large voltage divider followed by a buffer. Another
employs an inverting attenuator. The problems associated with
both methods stem from uneven power... |
Improve Voltage Readings By Doubling a DVM's Scale :
04/29/02 Electronic Design - Ideas for Design / The ubiquitous,
and now inexpensive, 1999-digit digital panel meter or digital
voltage meter (DVM) module is a very useful addition to the
range of test and display gear currently available. It's
accurate, robust, and easily scaled for ranges from... |
In Circuit Electrolytic Tester: |
Inclinometer: |
Indicator features expanded scale: 02/21/2002 EDN - Design
Ideas / Test equipment for a production line should be
user-friendly (read "idiot-proof") and should offer minimal test
time. In many cases, the test fixture must give an operator only
one answer: pass or fail. Usually, two indicators assume this
role: green for pass and red for fail. In most applications, a
sensor transforms the tested parameter to a voltage; the test
fixture must measure this v... . |
Indicator has Expanded Scale: 02/21/02 EDN-Design Ideas /
PDF contains multiple circuits - scroll to find the one of
interest |
Inductance meter : for 0.5 uH to 50 uh RF inductors,
displays on digital voltmeter |
Inductance Meter: |
Inductive Pickup: simple device for detecting
audio-frequency electromagnetic signals, such as those emanating
from a loudspeaker, or its cable |
Infrared Remote Control Tester #1: measures the relative
intensities of different Infrared light sources |
Infrared Remote Control Tester: |
Integrator Forms Picoammeter: 07/17/97 EDN-Design Ideas
|
Ion Detector: |
Isolated, 12bit, 8 Channel, a / D Converter With PC Interface &
0.1% Accuracy: |
LCD Frequency Counter (PIC16F84): |
LED Audio VU Meter: logarithmic scale with3 dB steps, based
in LM3915 IC |
LEDBarograph Driver: |
Light Meter: |
Light
Pollution Meter : LED brightness control circuit and a
multimeter to compare light levels to LED level.
|
Light Sensor Adapter for Oscilloscope: |
Lightening Detector: |
Line Output / Flyback Transformer tester:
|
Linearized RF Detector: |
Live Power Line Detector: |
Load Pulser Tests Supply's Transient Response: 04/11/96 EDN-Design
Ideas |
Load Simulator Maintains Constant Power: 04/11/96 EDN-Design
Ideas |
Logic Analyzer: |
Logic ChipTester: |
Logic Probe #1: |
Logic Probe #2: with probe |
Logic Probe #3: with probe, CMOS |
Logic
Probe With Pulse, CMOS: |
Logic Probe With Pulse: |
Low cost anemometer fights dust: 08/30/2001 EDN - Design
Ideas / As higher levels of power dissipation underscore
the need for cooling, more and more fans are finding their way
into small electronic enclosures. The dust that fans pull into
these enclosures can, however, cause major problems for
high-reliability systems. By coating heat sinks and electrically
charged components, the dust acts as a blanket that raises the
effective thermal impedance betw... . |
Low Cost Dot/bar Generator: |
Low cost relative humidity transmitter uses single logic IC:
11/08/2001 EDN - Design Ideas / The low-cost
percentage-relative-humidity radio transmitter in Figure 1
operates in a cold-storage warehouse for vegetable storage at
temperatures of 1 to 5 C. It is generally difficult to collect
such data from a low-temperature area with high humidity and low
illumination. The transmitter design is simple: It uses a
readily available, capacitor-type percentage-relative-humidity
se... . |
Low Tech DCC Meters: |
Machine Vibration Activates Hour Meter: 01/16/97 EDN-Design
Ideas |
Magnetometer: |
Make a Simple PC based Frequency Meter: 04/29/99 EDN-Design
Ideas / PDF contains multiple circuits - scroll to find this
circuit |
Making Differential Probes: for sensing audio signal
voltages across devices that are not ground referenced
|
Measure humidity and temperature on one TTL line: 08/30/2001
EDN - Design Ideas / By combining the responses of an
Analog Devices (www.analog.com) AD590 temperature sensor and a
Humirel (www.humirel.com) HS1101 humidity sensor, you can
generate a single TTL-level signal containing information from
both sensors (Figure 1). This design uses a 74HC123 monostable
multivibrator, IC1, to form a free-running oscillator. . |
Measure Inductance With DC Superimposed: 07/06/95 EDN-Design
Ideas |
Measure open circuited cables using a multimeter:
09/26/2002 EDN - Design Ideas / You can use a multimeter with
capacitance-measurement capability to measure the length of wire
or cable to an open circuit. The capacitance of a pair of wires
(or a wire to a shield) is directly proportional to the length
of the wire. If you know th. |
Measuring RF Voltages with a VOM: |
Method simplifies testing high Q devices: 02/21/2002 EDN -
Design Ideas / The design of low-phase-noise oscillators
requires careful attention to resonator unloaded Q. In the
construction of a low-phase-noise, high-frequency oscillator,
the goal is to achieve an unloaded-Q figure greater than 400 in
a reasonable package. Also, you need to monitor the effect of
the package and pc-board arrangement. . |
Micro Ohm Meter: |
Micro Volt Probe: |
Microphone Circuit Test Oscillator: 440 Hz Tone generator
for testing XLR microph1-lines |
Microphone Polarity Tester: |
MIDI Tester: |
Milli Ohm Adapter: |
MilliGauss Meter: |
Mini DDS (Direct Digital Synthesis): |
Mini DDS (direct Digital Synthesizer): |
Modified Scope Probe Tests SurfaceMount Assemblies: 09/25/97
EDN-Design Ideas |
MOSFET Current Sensing: Method of mirror current sensing a
MOSFET |
MOSFET tester: |
Multi Wire Cable Tester: |
Multicore Cable Tracer: |
NiCd Battery Discharger / Capacity Indicator:
|
Off Line Telephone Tester: Here is a circuit of an off-line
Telephone tester which does not require any Telephone line for
testing a Telephone instrument. The circuit is so simple that it
can be easily assembled even by a novice having very little
knowledge of electronics. FAIR WARNING -- THIS SITE HAS ANNOYING
POP UP ADS. |
OpAmp Design & Test Board: |
Owens Bridge Inductance Measurement Device:
|
Paralleling RMS Converters Speeds Settling.: 05/26/94 EDN-Design
Ideas |
PC Based Digital Storage Oscilloscope (DSOA):
|
PC Based Digital Storage Oscilloscope Mk3:
|
PC hardware Monitor Reports the Weather: 01/18/01 EDN-Design
Ideas / PDF contains multiple circuits - scroll to find the one
of interest -
|
PCB maximum trace current: |
PCB VSWR Bridge: |
pH Meter #1: |
pH Meter #2: |
pH Meter With Calibration: |
Phantom Power Battery Test Circuit: LED will light when
battery is over42 volts |
PIC Logic Probe With Pulser: |
Picoammeter Circuit With Four Ranges: This circuit uses a
CA3420 BiMOS op amp to form a picoammeter with4 ranges. The
exceptionally low input current (typically0.2pA) makes the
CA3420 highly suited for use in a picoammeter circuit. Input
transient protection is provided by the1 megohm resistor in
series with the input. The10 megohm resistor connected to pin2
decouples the potentially high input capacitance often
associated with lower current circuits and reduces the tendency
for the circuit to oscillate under these conditions. The10k
potentiometer is used for null offset. |
Pink Noise Generator for Audio Testing: |
Pink Noise Generator: |
Polarity Detector: |
Polarity Sensing Continuity tester: |
Power Factor Meter: |
Pre Distortion Techniques: Tape Linearizer and a Distortion
Analyzer |
Precision Audio Frequency Peak Detection Probe : for use
with a digital voltmeter |
Precision Audio MilliVoltmeter: Measures10mV to50Volt RMS in
eight ranges Simply connect to your Avo-meter set @50�A range
|
Pulse Generator & Signal Tracer: Dual-purpose
test-instrument Very simple Circuitry,1.5 Volt
Battery-operated |
Pulse Generator Verifies Test Setups: 05/26/94 EDN-Design
Ideas / Verifying the rise-time limit of wideband test-equipment
setups is a difficult task. In particular, you must often know
the "end-to-end" rise time of an oscilloscope/probe combination
to ensure measurement integrity. Fig1s circuit provides an
800-psec pulse having rise and fall times shorter than250 psec.
The pulses amplitude is10V, and the circuits source impedance
is50 Ohm.
|
Pulse Reading Logic Probe: |
Ramp Generator: |
RCM710 Electronic Scale: |
Remote Control using Telephone: Here is a tele-remote
circuit which enables switching "on" and "off" of appliances
through Telephone lines. The circuit described here can be used
to switch up to nine appliances (corresponding to the digits1
through 9 of DTMF the Telephone key-pad). The Telephone can be
used to switch on or switch off the appliances also while being
used for normal conversation. FAIR WARNING -- THIS SITE HAS
ANNOYING POP UP ADS. |
Remote Field Strength Meter: |
Remote humidity sensor needs no battery: 04/04/2002 EDN -
Design Ideas / Using ac-line power sources and batteries
for remote humidity sensors is undesirable because these sources
can be troublesome if you mount them in inaccessible points,
such as smokestacks, cold-storage chambers, or darkrooms, where
maintenance is difficult and inconvenient. Figure 1 shows a
simple way to remove the power source from the humidity-sensor
circuit. . |
Resistance tester: |
Resistor Decade Box: |
RF Power Meter for the QRPer: |
Ring Oscillator Measures Cable Length: 05/12/94 EDN-Design
Ideas |
RJ45 Cable Tester: |
RMS to DC Converter is Accurate & Stable: 09/14/95 EDN-Design
Ideas |
Scope Probe Measures High Frequencies: 01/18/96 EDN-Design
Ideas |
Self Heated Transistor Digitizes Airflow: 03/14/96 EDN-Design
Ideas |
Self Oscillating Amplifier for Distortion Testing: allows
the home constructor to make quite accurate measurements,
without having to spend a lot of money on a low distortion
oscillator |
Self Powered Fast Battery Tester: Tests1.5 to15 Volt
cells2-LED display, no power supply required
|
Sensitive RF Voltmeter: |
Short Circuit Beeper: |
Short Circuit Finder uses Few Parts: 11/05/98 EDN-Design
Ideas |
Signal Conditioning Precisely indicates Humidity: 02/02/98
EDN-Design Ideas |
Signal Generator for Signal Tracer: |
Signal Injector: |
Signal Tracer / Injector: |
Simple 6 Digit 40MHz Frequency Counter Module:
|
Simple BER meter is easy to build: 03/02/00 EDN-Design Ideas
/ A bit-error-rate (BER) tester is a basic tool for
digital-communications measurements. Although many commercial
BER testers are available, you can easily design and build an
inexpensive version. The scheme in Figure 1 has performance
similar to that of a... |
Simple Circuit Measures VI Phase Displacement : 08/19/02
Electronic Design - Ideas for Design / This circuit provides
different ways to measure the current-voltage phase displacement
of a line-powered ac load. The classic approach for sensing an
ac load's current requires a transformer or sensing resistor.
The transformer may be expensive,... |
Simple circuit provides high side current sensing: 10/12/00
EDN-Design Ideas / PDF contains multiple circuits - scroll to
find this circuit |
Simple Circuit Provides Timebase Calibration: 04/24/97 EDN-Design
Ideas |
Simple Circuit Uses Optical Fiber To Send RelativeHumidity Data
: 04/01/02 Electronic Design - Ideas for Design / The
circuit shown in the figure measures relative humidity in air at
the low temperatures found in applications like cold storage of
food items and greenhouses. Instead of using electrical signal
cables that... |
Simple emulator speeds testing : 09/25/03 EDN-Design Ideas
/ Designing and testing embedded hardware can be frustrating if
you have to rely on somebody else's perhaps-unready firmware to
test your hardware. Often, hardware is ready for testing before
debugging and system firm-ware are available from software
developers. Microprocessor emulators are solutions but are often
expensive, hard to use, and sometimes inappropriate for use by
hardware developers,...... |
Simple ESD gun Tests IC: 09/12/96 EDN-Design Ideas
|
Simple Field Strength Meter: |
Simple Logic Probe uses Bicolor LED: 03/13/98 EDN-Design
Ideas |
Simple Technique Measures Small Capacitance: 09/01/97 EDN-Design
Ideas |
Simple tester checks LCDs: 10/03/2002 EDN - Design Ideas /
Manufacturers of electronic equipment use LCDs for calculators,
watches, mini-videogames, and pagers, for example. In comparison
with LED-based displays, which consume power on the order of
tens of milliwatts, an LCD consumes only a few microwatts. The
LCD thus saves power by a factor of approximately 1000.. |
Simple, LowCost Capacitor Matcher Replaces Expensive Lab :
11/11/02 Electronic Design - Ideas for Design / Matching several
capacitors, without needing a really precise value, can be
accomplished with a "high-tech" laboratory capacitance meter.
But this is cumbersome and overkill, and not everyone has one.
This simple circuit matches, compares, and even... |
Solar Current Meter: |
Sound Level Meter: |
Strain Gauge Sensor: |
Synthetic Isolators: great for checking the SWR of antennas,
amplifiers, mixers, etc. |
TDR Reflectometer: |
Telephone Test Circuit With Audio Mixer: get Telephone audio
to mixer or send audio to Telephone |
Temperature Compensated PH Meter: |
Temperature Monitor: |
TempSentry Temperature Sensor Technical Info & Schematics:
|
Test Batteries Without a Voltmeter: 11/09/00 EDN-Design
Ideas / PDF contains multiple circuits - scroll to find the one
of interest / This circuit an easy approach to testing batteries
without exiting the voltmeter. The battery holders in sizes AAA,
AA, C, and D make this tester so much faster than a voltmeter.
|
Test Plug: |
Three Channel Spectrum Analyzer: This Three channel15 LED
spectrum analyzer can be used as an addition to any audio amp
project. It produces fantastic displays on3-LED bars that can be
individually adjusted for any particular frequency range.
|
Three Level Audio Power Indicator: Battery-operated Three
LED display that connect it to loudspeaker output
|
Time and Frequency Circuits: |
Time Domain Reflectometer (TDR): |
Time Domain Reflectometer: |
Time tag impulses with zero crossing circuit: 01/24/2002
EDN - Design Ideas / A "constant-fraction discriminator" usually
performs the time-tagging of impulsive events, which have a
peaking time of the signal amplitude. The implementation of this
technique requires a delay in the input signal of approximately
the same amount as the signal's rise time. You can attain this
delay by using a coaxial cable of an appropriate length. . |
Tonal Voltmeter gives Audible indication of Voltage Level:
|
Trace voltage current curves on your PC: 10/11/2001 EDN -
Design Ideas / Some years ago, one of the fundamental electronic
instruments was the laboratory curve tracer. A CRT display would
sweep out terminal behavior (current versus voltage) from which
you could derive mathematical models. Classic presentations of
diodes, transistors, and other devices enlightened designers
about linear and nonlinear operation. . |
Track multisite temperatures on your PC: 04/18/2002 EDN -
Design Ideas / The low-cost circuit in Figure 1 allows you to
track four remote temperatures with thermistor sensors through
the parallel port on your PC. This four-zone thermometer
instrument has a temperature range of -40 to +90 C and a
resolution of better than 1 C. You can calibrate its accuracy to
within 1 C over a 0 to 50 C span and within 3 C over a -40 to
+90 ... . |
Transistor & FVCs Make Linear Anemometer: 09/26/96 EDN-Design
Ideas |
Transistor Spot Checker: |
Transistor tester fits into your pocket: 12/20/2001 EDN -
Design Ideas / It can be helpful to rapidly and easily determine
the polarity (npn or pnp) and function of a transistor. The
pocket-transistor tester in Figure 1 is ideal for quickly
testing without regard to such parameters as gain and frequency
response. You connect the transistor, or device under test,
between the collectors, T, of an astable multivibrator. |
Transistor Trio Makes Vector Anemometer: 09/01/97 EDN-Design
Ideas |
Transmission line tests 1 kW device using only 100W:
02/20/03 EDN-Design Ideas / A 13.56-MHz, ISM (industrial,
scientific, and medical)-band RF-measurement device had the test
requirement of a 50-hour, 1-kW burn-in. The device under test
needed to be simultaneously stressed at an RF potential and RF
current equivalent to 1 kW, but the only spare RF source at hand
was a 100W RF generator... |
Transmitter accurately transfers voltage input: 05/15/03
EDN-Design Ideas / When you connect remote sensors to a central
process controller, a simple, robust, and commonly used
interface is the 4 to 20-mA loop. The advantages of this current
loop include the simplicity of just two twisted wires that share
both power and signal, the loop's high noise immunity in harsh
environments, and the de facto loop standard within the
process-control industry... |
Tri Waveform Generator: |
Triangle and Squarewave Generator: |
True RMS
Detector: National Semiconductor Application
Notes,28-Jun-1996 |
TTL Pulse Reading Logic Probe: |
Two Sensors Measure Three Line Currents: 09/01/95 EDN-Design
Ideas |
Two Tone Audio Oscillator (use for SSB Tests):
|
Ultra Simple Voltage Probe: |
Understanding Peak Reading Meters: includes1-example circuit
diagram |
UTP Cable tested: |
V/I Curve Tracer: |
Versatile power supply load uses light bulbs: 02/07/2002
EDN - Design Ideas / Improvising loads for bench-testing and
designing power supplies is often a frustrating and sometimes
hazardous experience. When you push large power resistors to
their limit, they tend to burn benches and melt solder
connections. Many electronic loads are on the market but are
usually expensive and of laboratory-type precision and often
represent overkill for the average designer. . |
Versatile Zener Diode Tester: |
Voltage Probe: |
Voltage Reference improves JFET: 10/26/00 EDN-Design Ideas /
PDF contains multiple circuits - scroll to find this circuit The
common JFET current-source in Figure 1a has average output
impedance and depends heavily on the JFET's V P and I DSS
variations. These manufacturing variations limit the initial
accuracy of the current setpoint that the circuit can obtain
with a...
|
Voltmeter: |
VU & PPM Audio Metering: circuits using analog needle
meters |
VU Meter Amplifier: |
VU Meter: 5 led VU meter, in PDF format, includes circuit
board, text in Finnish |
VU Stereo Meter: will indicate the volume level of the audio
going to your speakers by lighting up LEDs, based on LM3915 IC |
Weighting Filter: |
Wire Tracer Transmitter: |
Wireless Weather Monitoring Station: |
XR2206 Function Generator: |
Zener Diode Tester: |