This circuit was found in an American magazine 73 for radio amateurs of the 80s. It is an automatic transmission circuit for telegraphy. The circuit is TTL.
June 2016 - It can be purchased from Mouser Electronics the new triacs Z04 for 4 A from...
The HA2620 integrated circuit used in this comparator is from the 80's, but the setting can be...
Using a Norton operational amplifier circuit, we have in the figure a variable voltage regulator. The...