EDN

Simple circuit forms multichannel temperature monitor

You can use an ADT7461 single-channel temperature monitor, an ADG708 low-voltage, low-leakage CMOS 8-to-1 multiplexer, and three standard 2N3906 pnp transistors to measure the temperatures of three ...
Electronic Design

Simple Electronic Lock Uses Single-Transistor Circuit

A very simple but highly efficient combination lock circuit is shown in the figure. Any type of on/off switches can be used, varying from commercially available inexpensive types to more sophisticated ...
Ars Technica

Electronics people: simple drive spin-up transistor switch, with ~0.5s timer

OK, so I have an old project laptop with an IDE/PATA/slim-ATAPI optical drive bay, into which I have inserted a SATA drive caddy with a bridge board. The thing is, the caddy doesn't transfer the drive ...
EDN

Simple Siren Circuit

This circuit generates a tone that sounds very similar to a siren. The generator part of the circuit is made of the combination of PNP and NPN transistors. Toghether, the two transistors build up a ...