Door buzzer or alarm (CB20492E)

This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose NPN.

TTL and CMOS Optical Shield (CB4248E)
This circuit, from an old ON Semiconductor publication, suggests a shield to excite an LED from an...
860 W dimmer (CB5279E)
This circuit was obtained from an old American documentation having a limited adjustment range....
New tinyAVR® MCUs Increase System Throughput While Lowering Power Consumption in Embedded Applications
Microchip Continues Expansion of AVR Microcontroller Product Line with Addition of Three New...