Click here to view a PDF of all the Design Ideas from this issue. Using a CMOS 555 timer and a single NPN transistor, you can drive as many as seven LEDs using a minimal amount of voltage and power ...

This is a small size led flasher built with the 555 timer IC that is powered from 2 x 1.5V batteries. The circuit can be used as a flashing metronome, dark room timer, memo-reminder or other similar ...

This voltage-booster circuit for driving one or more white LEDs uses a 555 timer as its main element (see the figure). The timer, IC1, functions as a resettable astable multivibrator where R1, R2, and ...