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Regulator Monitors Its Input Voltage - 09/12/97 EDN-Design
Ideas.... EDN is migrating links. This link is not verified.
Google the "title" + EDN for new link. |
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Remote Control Transmitter - Although ready-made remote
controls are easy to get, with this project we show how to build on at
home. Features are impressive, with 6 radio channels and long battery
life. Complete with PCB layout. (electronic design added 6/07)
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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....(added 5/02)
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Remote humidity sensor needs no battery - 4-Apr-02 Issue of
EDN 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.... [Design Idea by Shyam Tiwari, Sensors
Technology Private Ltd, Gwalior, India] |
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Resistance tester - Schematic only, no circuit description |
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Resistance, DC Current, AC Current & Frequency & Period Measurement Errors in
Digital Multimeters AN-1389-2 - Aligent Application Note (app note
added 4/08) |
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Resistor Decade Box - (schematic / circuit added 6/07) |
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Revolution Meter - Revolution meter by measuring method of strobe
synchronization. It can measure up to 100,000 rpm in two ranges. (added
6/06) |
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RF detectors, level meters, attenuators, dummy loads, signal dividers several
circuits on this page…. [Jan-Martin Nøding's site] |
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RF Isolator Uses Differential Amplifiers - An RF isolator is a seemingly
magic device that allows signals to pass in only one direction. Signals applied to
the input port are sent to the test port and signals coming into the test port can
only go to the output port. This one-way property is usually accomplished with
special non-linear ferrite/magnet structures operating at very high frequencies.
Fig. 1 shows an active RF isolator.... [Design by Charles Wenzel] |
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RF Power Meter - Many beginners trying out their skill with QRP TX, for
the first time have to overcome many problems before they are able to come on the
air. On usual complaint is that, every thing is working fine but the signal is not
going out. Here is a simple set up which will enable them to measure the out put
power of their transmitter. All that they require is a good multimeter which has a
sensitivety of 20k ohms/4 Watts which is adequate for low power transmitters. The
8k resistor should be kept close to the out put terminal of the
transmitter....(electronic circuit added 9/04) |
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RF Power Meter for the QRPer - amateur radio construction projects….
[from Peter Parker's website] |
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RF Probe - Use this probe with any transmitter for tuning. Connect the
probe at the output of each stage and tune till maximum DC voltage appear on
Digital Voltmeter. (added 11/05) |
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RF signal- and power generators several circuits on this page…. [Jan-Martin
Nøding's site] |
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Ring oscillator measures cable length - 05/12/94 EDN-Design Ideas....In
Fig 1, an ECL exclusive-NOR gate (F100107] and a length of cable form a simple
ring oscillator. The delay from the cable and the gate determine the ring
oscillator’s frequency. A 100m cable yields approximately a 600-MHz oscillation
frequency. The gate’s second output connects to a frequency counter.
EDN is migrating links. This link is not verified. Search the "title" + "EDN"
for new link. |
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RMS Calculations for Energy Meter Applications Using the ADE7756 -
AN-578 Analog Devices Application Notes....[App Note] The document describes
the implementation of an rms signal processing algorithm using the ADE7756 and a
Microcontroller (PIC16C63) from Microchip. |
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RMS to DC Converter is Accurate & Stable - 09/14/95 EDN-Design
Ideas....Combining the well-known true RMS-to-dc circuit with a simple S/H circuit
eliminates offset errors, which increases accuracy and temperature stability. The
circuit in Fig 1 uses a low-cost analog multiplier, IC1; an integrator, IC3A, R5,
and C1; and an analog inverter,.... EDN is migrating links. This link is not
verified. Search the "title" + "EDN" for new link. |
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Rohde & Schwarz FTZ distortion meter schematic - (circuit added
07/07/07) |
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Rohde & Schwarz LARU Inductance meter schematic - (circuit added
07/07/07) |
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RS 232 to TTL converter tests UARTs with a PC - 29-May-08 Issue of EDN
A simple RS-232-to-TTL converter tests UARTs using a PC's serial port for
power.... [Design Idea by Matthieu Bienvenüe, Malissard, France] |
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RS232 Data Bus Status Indicator - This circuit indicates TXD and RXD
activity. The thresholds are set at plus 3 volts and minus 3 volts. (added
12/04) …. [Hobby Corner Circuit by Dave Johnson] |
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RS232C Link Monitors Animal Activity - 11/06/97 EDN-Design Ideas....A
common need in biological experimentation is the ability to unobtrusively monitor
the activity of small caged animals, such as mice, rats, and rabbits, as they move
about their enclosures. This monitoring must be over long periods and around
the clock. The circuit in.... [Design Idea by W Stephen Woodward, University of
North Carolina--Chapel Hill] |
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RS232-to-TTL converter tests UARTs with a PC - 01-Jul-08 EDN
Europe When using a computer for debugging or testing UARTs you often need
an RS232-to-TTL adapter. But most of these adapters require an external
power-supply adapter to power up the RS-232 transceiver. This external
adapter increases the number of cables on your desk and uses no flowcontrol
signals.... [Design Idea by Matthieu Bienvenüe, Malissard, France] |
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