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November 25, 2010
The purpose of this circuit is to animate shop-windows by means of a capacitive sensor placed behind a post-card-like banner. [more]
November 25, 2010
Can be used agains ferocious animals or attackers, BUT REMEMBER, this device may be illegal in your state. [more]
November 25, 2010
This circuit generates a good 1KHz sinewave using the inverted Wien bridge configuration. [more]
November 19, 2010
This circuit operates two LED strips in pulsing mode, i.e. one LED strip goes from off state, lights up gradually, then dims gradually, etc. while the other LED strip do the contrary. [more]
November 19, 2010
This circuit has been designed to alert the vehicle driver that he has reached the maximum fixed speed limit (i.e. in a motorway). It eliminates the necessity of looking at the tachometer and to be... [more]
November 18, 2010
This circuit was designed as an aid in parking the car near the garage wall when backing up. LED D7 illuminates when bumper-wall distance is about 20 cm. [more]
November 18, 2010
Time is set by potentiometer R2 which provides a range or 1 sec. To 100 seconds with timing capacitor C1 of 100uF. The output at pin 3 is normally low and the relay is held... [more]
November 18, 2010
This circuit is intended to signal when a plant is needing water. A LED illuminates at maximum brightness when the ground in the flower-pot is too dry: it dims gradually as the water's content in... [more]
November 16, 2010
Stethoscopes are not only useful for doctors, but home mechanics, exterminators, spying and any number of other uses. Standard stethoscopes provide no amplification which limits their use. This circuit uses op-amps to greatly amplify a... [more]
November 16, 2010
This low voltage circuit can be used to monitor batteries and other volatile sources of current for problems. The circuit sounds an alarm and lights an LED, but can be interfaced to any number of... [more]
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