This circuit was published in an article in Radio Electronics magazine in October 1988. It uses components that are still common today, except for the sensor, which is a special type from that time.
This circuit, from an old ON Semiconductor publication, suggests a shield to excite an LED from an...
This circuit uses in operational amplifier to produce square and triangular low frequency signals....
June 2016 - It can be obtained from Mouser Electronics this new chip for motor control, motion,...