This circuit was found in a Popular Electronics from the 90's. The CMOS integrated circuit used is not very common nowadays. The range depends on the infrared LEDs. R7 can be changed.
This 12V battery charging circuit automatically shuts off at the end of the charge. The disconnect...
We do not know exactly what sound a flying saucer makes, or if it makes a sound! But this is not...
This simple 1 transistor circuit was found in an American documentation from the 60's. The...