2N4987 and 2N4990 (IP057E)

Unilateral switch (SUS) with 8 V of trigger voltage. This component is used to control SCRs and other applications.

Receiver for remote control (CB23859E)
Published in Radio Electronics in January 1963, this circuit uses 5 transistors of the time. The...
Sound Filter (ART179E)
In its first version this article was written in Portuguese for a Brazilian magazine and...
Manually triggered VCO (CB19082E)
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...