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.
The filter shown in the figure can have its cutoff frequency adjusted between 2 kHz and...
This circuit can be used in the car to control the windscreen wipper or with other appliances at...
n, but is currently valid with the use of a common transistor and SCR. The circuit must be powered by an...