The transistor used in this circuit is uncommon today. AC124 or equivalent such as AC188K and 2N2431 can be used. The circuit is from the 80's and makes use of transformers.
The purpose of this circuit is to improve a trigger circuit using a zener diode. The circuit was...
The Exclusive-NOR function can be achieved simply by adding one more NAND gate as an inverter to...
This simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is...