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10mhz to 20mhz Laser Light Detector - This circuit was originally designed to
detect laser light pulses for an optical Ethernet communications system. It has good
ambient light immunity. ….(designed by David A. Johnson) |
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10W HF Linear Amplifier - (circuit / schematic design added 6/06) |
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20MHz VCSEL 3mW Laser Test Circuit - This circuit takes advantage of some new
vertical cavity surface emitting lasers (VCSEL) that don’t require light output
control circuits. The circuit shows how to drive the device from a single high speed
CMOS IC. The circuit can easily be modified to transmit signals from kilohertz to
about 50MHz. ….(designed by David A. Johnson) |
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27MHz toy car receiver - (circuit / schematic design added 6/06) |
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300v Peak To Peak Signal Generator - This circuit converts a square wave signal to
a +-150 volt output signal with fast 100nS rise and fall times. ….(designed by David
A. Johnson) |
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3W HF QRP Linear Amplifier - (circuit / schematic design added 6/06) |
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5 Watt HF CW transmitter - This is a very simple 5 watt CW TX based upon a TTL
logic chip. There is just one "tricky" component and this is Cx. This component should
have an impedance of about 10 - 50 ohms at the frequency of interest. If you wish to
reduce the transmitter power, increase the value of Cx. It is Cx which causes the
square wave from the output transistor to approximate a sine waveform. The value of Cx
is the price of simplicity in this TX.....(schematic added 03/04/05) |
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500mW HF Linear Amplifier - (circuit / schematic design added 6/06) |
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500w HF Linear Amplifier - (circuit / schematic design added 6/06) |
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Active Antenna for Am-Fm-Sw - (Tony van Roon's circuit / schematic design added
6/06) |
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Active Antenna for HF-VHF-UHF - (Tony van Roon's circuit / schematic design added
6/06) |
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Broad Band 2MHz Optical Fiber Receiver - If you need more sensitivity than the
above circuit this circuit provides about ten times more gain. It too is designed
around an inexpensive plastic optical fiber detector. ….(designed by David A. Johnson) |
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Broad Band 5mhz Optical Fiber Receiver - This circuit is a simple broad band light
detector that uses a very inexpensive IC and a PIN photodiode that is packaged for use
with plastic optical fibers. It has a bandwidth from 1KHz to over 5MHz. It is great
for experimenting with various modulated light sources. ….(designed by David A.
Johnson) |
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Build an Adjustable High Frequency Notch Filter - 02/06/03 EDN-Design Ideas:
Although you can obtain universal, resistor-programmable switched-capacitor filters
that are configurable as notch filters, most cannot operate at bandwidths higher than
100 kHz. Furr, typically 16to 20-pin packages do not include a continuous-time,
antialiasing filter to prevent spurious signals from appearing at output.....(design
idea added 12/04) |
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CMOS Inverter Makes Low Power Amp - With the addition of one resistor and a
capacitor, some common logic ICs can be transformed from digital to analog duties.
This circuit outlines some the features to expect from different inverter ICs.
….(designed by David A. Johnson) |
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Composite Amp Provides High Gain & Bandwidth - 04/28/94 EDN-Design Ideas: The
composite circuit in Fig 1 couples the output drive and slew rate of a
current-feedback amplifier, IC2, with the low-noise and low-offset characteristics of
a voltage-feedback operational amplifier, IC1. The circuit achieves gains as high as
1000, while showing little variation in frequency characteristics with gain. This
circuit suits applications..../.....(design idea added 04/02) |
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Dip Oscillator for HF - (circuit / schematic design added 6/06) |
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FET Input High Speed Light Detector - This circuit is yet another design that
converts current from a PIN photo diode to a voltage. It has a bandwidth that
extends beyond 50MHz. ….(designed by David A. Johnson) |
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Flashing LED Advertising Badge #2 - This circuit is similar to flashing LED
advertising badge #1. . It uses a CD4013 dual D Flip/Flop IC. The 74HCT74 IC in #81
does not always work. As in #81, a single lithium battery will provide months of
continuous LED flashing. It also has a tiny push-button switch to turn on and off the
light flashing. ….(designed by David A. Johnson) |
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High voltage high frequency Amplifier drives piezoelectric PVDF transducer -
07/24/08 EDN-Design Ideas: Finding wide use in nondestructive testing, a high-voltage,
high-frequency amplifier drives a piezoelectric PVDF transducer.....(design idea added
09/08) |
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How to build Amplifier 2x30W with STK465 - A amplifier of acoustic frequencies can
be manufactured with discernible materials, despite is known so much the difficulties
of finding of materials, what the problem of regulations. These difficulties are
overcome relatively easily if we find amplifier in form completed.....(circuit added
08/08) |
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Laser Light Detector, 10mhz to 20mhz -
This circuit was originally designed to detect laser light pulses for an optical
Ethernet communications system. It has good ambient light immunity. ….(designed by
David A. Johnson) |
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LF to HF Converter (Peter Parker) - This converter allows reception of signals
below 500 kHz on a 3.5 – 4 MHz HF receiver. It should therefore be useful for those
with receivers that do not receive the lower frequencies….(electronic schematic /
circuit added 2/05) |
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Medium Power Wideband Amplifier for MMDS Applications 5/30/98 - Application Note
California Eastern Laboratories Doc #911 (app note added 6/06) |
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N-CH & P-CH Transistor form Push-Pull Driver - This circuit can produce high speed
output signals with fast rise and full times. The unique change pump action allows the
voltage of the upper P-ch device to range from millivolts to hundreds of volts. The
output current is only limited by the rating of the transistors. I have used this
circuit beyond 2MHz. ….(designed by David A. Johnson) |
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QRP HF Transmitter - (electronic Circuit added 03/06) |
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Single-Sideband Demodulator Covers the HF Band - 10/26/00 EDN-Design Ideas: The
circuit in Figure 1 complements a previous Design Idea ( SSB modulator covers HF band
EDN , Sept 30, 1999, pg 122). The modulator employs a phasing....(design idea added
08/08/08) |
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Synthesized HF Receiver - (circuit / schematic design added 6/06) |
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TBA120 Narrowband FM Receiver - (circuit / schematic design added 6/06) |
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Wide Band RF Amplifier for 10MHz-500MHz Input - This paper describes an RF
amplifier circuit which is suitable for the frequencies between 10MHz and 500MHz.
These kind of amplifiers are called wide band amplifiers.(07/07/07) |
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Wide Band Zero Cross Detector - This circuit was designed to convert a low
amplitude 40KHz signal into a clean square wave signal. It will work with inputs as
small as 5mv peak-to-peak or as large as 3 volts peak to peak. The input frequency
can range from a few kilohertz to about 150KHz. ….(designed by David A. Johnson) |
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Wideband AGC has 60 DB Dynamic Input Range - 10/10/96 EDN-Design Ideas:
/.....(design idea added 5/02) |
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Wideband Low Distortion Techniques Apex-AN17 - Apex App Note (added 08/08/08) |
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Wideband Low Noise Amplifier Drives 50 Ohm Loads - 10/23/97 EDN-Design Ideas:
/.....(design idea added 4/02) |
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Wideband Op Amp Capable of µPower Operation - National Semiconductor Application
Note 24-Oct-2001 (app note added 1/03) |
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Wideband peak detector operates over wide input frequency range - 11/22/07 EDN-Design
Ideas: An ultrafast comparator and associated circuitry enable peak detection over a
wide input-frequency and -voltage range.....(design idea added 9/08) |
