|
+/- 1.0V Current-to-Voltage Converters - This current to voltage converter rely on
the very high input impedance of the operational amplifier. The input current
(I) is forced through feedback…Circuit Ideas for Designers Application Notes Advanced
Linear Devices, Inc. (app note added 6/06) |
|
+/-2.5V Current-to-Voltage Converters - Circuit Ideas for Designers Application
Notes Advanced Linear Devices, Inc. (app note added 6/06) |
|
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) |
|
1us Light Pulse Receiver Plus Post Amp - This circuit is designed to detect very
weak light pulses lasting 1uS. It uses a tuned LC feedback network to provide high
sensitivity while giving high ambient light immunity. A post voltage amplifier is
included with a gain of about X20. The circuit is described in more detail in the
receiver section of my Handbook of Optical Through the Air Communications. Note:
The LF357 op amp is no longer available, this circuit is for reference only.
….(designed by David A. Johnson) |
|
4 to 20 Mloop Needs No External Power Source - 09/13/01 EDN-Design Ideas:
simple circuit in Figure 1 uses a low-current-drain MAX407).....(design idea added
02/05) |
|
40kHz Laser Burst Detector - This circuit was originally designed to detect weak
flashed of laser light bounced off of a fabric video projection screen. It was used as
part of a firearm training system. It generates a 100mS output pulse whenever it
detects a 3ms to 5ms-laser burst, modulated at 40KHz. It is very sensitive and could
be modified for long-range laser communications. ….(designed by David A. Johnson) |
|
40kHz Light Receiver Is Immune to Ambient Light - If you want even more
sensitivity than the above circuit, try this design. When used with a one-centimeter
square photodiode, you can achieve a range of several hundred feet with a standard TV
or VCR remote control module. ….(designed by David A. Johnson) |
|
40kHz Modulated Light Detector - This circuit uses a unique cascode amplifier
circuit to convert the current from a PIN photo diode to a current without any
feedback network. It is very stable and very sensitive. The circuit shown has the
potential for a conversion factor of 10 volts per microwatt at 900nm. I included a
simple JFET post-amplifier with a gain of about 20. ….(designed by David A. Johnson) |
|
Air Transparency Monitor - I designed this circuit many years ago to monitor the
quality of a mile long column of air for future optical communications experiments.
The transmitter system (circuit 72 below) uses a powerful xenon flash in conjunction
with a large 12 inch Fresnel lens at the transmitter end and a matching 12-inch lens
with a PIN photo diode at the receiver. The receiver system was connected to a weather
station and a computer to collect the changes in intensity of the light flashes under
different weather conditions. It has the potential for a 30+-mile range. I have also
used this system to conduct cloud bounce experiments. ….(designed by David A. Johnson) |
|
Air Transparency Monitor, page 2 - This is Page 2 of the receiver circuit Air
Transparency Monitor, Xenon Flash Receiver ….(designed by David A. Johnson) |
