You know how it is. You’ve got that new project running, and while it doesn’t consume much power, it also doesn’t give much indication of whether it’s functioning or just sitting there with a dead ...

The circuit was designed to be used as flashing eyes in Halloween gadgets with the addition of rhythmic music or speech while being powered by 3 V battery. BC547 – NPN small signal transistors ...

The 555 circuit below is a flashing bicycle light powered with four C,D or AA cells (6 volts). Two sets of 20 LEDs will alternately flash at approximately 4.7 cycles per second using RC values shown ...