This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The transistor admits equivalent as 2N2222 or BF494. The circuit is from an old American publication.
This circuit was found in a 1992 Electronics Hobbyst Handbook. The circuit is for the 110 V power...
The TBA810 integrated circuit is no longer common today. This circuit shows an application of this...
This soft starter dimmer was found in a 1980s documentation. We can implement it with current...