Tag Archives: circuits


Here’s a digital stop watch built around timer IC LM555 and 4-digit counter IC with multiplexed 7-segment output drivers (MM74C926). IC MM74C926 consists of a 4-digit counter, an internal output latch, npn output sourcing drivers …

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Rain Alarm

This circuit gives out an alarm when its sensor is wetted by water. A 555 astable multivibrator is used here which gives a tone of about 1kHz upon detecting water. The sensor when wetted by …

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