This circuit was obtained in a Hands-On Electronics from the 90's. The circuit turns on one LED at the end of the timer, erasing the other. The timing can be increased by changing C1.
This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time...
The shunt type regulators are connected in parallel with the load, deflecting the current to...
In the figure we have the way to implement a NO OR or NOR gate with an operational amplifier. The...