We found this circuit in a Poptronics from 1998. The circuit can be extended to more competitors with another 4011. The power can be made with voltages from 6 to 12 V.
The 4007 integrated circuit consists of 4 MOSFETs that can be used separately. The figure shows how...
August 2016 - It can be obtained from Mouser Electronics new operational amplifiers with extremely low...
This circuit triggers an alarm in the event of a power failure. The circuit is from an 80's...