Found in English documentation from the 1990s, this circuit can employ equivalent components. The capacitor must be low leak type. The circuit can operate as a shield.
Found in Philips' 90s documentation, this small source can use modern transistors like the BD135...
This circuit is designed to activate an automotive alarm after 8 minutes of activation. Of course...
June 2016 - It can be purchased from Mouser Electronics the new triacs Z04 for 4 A from...