Found in a Philips documentation from the 90s, this circuit uses transistors from that time. Modern general-purpose transistors can be used.
Found in old documentation, this circuit applies to almost any common operational amplifier or...
Found in Harris' 90s documentation, this circuit uses a zener as a stabilizer. The signals...
The circuit is from a 1978 publication and the transistor may be the BC558. The transformer is...