Tag Archives: 555 timer

Lead-acid battery desulfator

Sulphation is a common problem in lead-acid batteries which usually happens when the battery remains idle for a long period. The sulphuric acid inside the battery react with the electrodes to form sulphate crystals that eventually deposit on the electrodes resulting into sufficient reduction in the efficiency. It has been found from research that the deposited layer of sulphate crystals may be broken down by applying high current pulses to the terminals of the battery. This instructabledescribes a desulfator circuit using 555 timer IC to reverse this process and rejuvenate the battery to like new condition.

Battery desulfator

555 Contest Entry: “Whack a Mole” style game

Jim Chen made a very interesting LED chasing game that uses six 556 timer chips. This is his second entry to the 555 contest which is recently closed. There are nine LEDs in the game. Any of them could glow randomly. The player has to turn off the LED by touching an electrode next to the LED. While the player continue playing the game the time available for the player is less and less. When you missed to turn off an LED within the provided time frame, the game is over. Here’s how the game works. Read more

555 Contest Entry: Motion activated camera

This entry for the 555 timer contest is from Andrew Smith who built a motion activated switch for a digital camera. The 555 timer is operating in monostable mode which is triggered by a PIR sensor when motion is detected. The monostable output of 555 then activates the camera through a remote.

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