In order to help his friend prepare for a talk at DEFCON this weekend, [Craig] built an IR photodiode amplifier circuit. The circuit extended the detection range of the hack from a few inches to ...

How to use negative feedback to regulate output power from a laser diode using a simple, single op-amp based circuit ...

It is monitored by the simplest of circuits which uses just one chip: an LM324 op-amp. There are three basic stages which he explains well in the video after the jump. The incoming signal is ...

Using a bootstrapping scheme with a JFET can enhance a photodiode’s ac response, but adds unwanted dc voltage. Remedy that problem with a matched dual-JFET. 1. This circuit uses a JFET to ...