This game was found in an old Popular Electronics. The unijunction transistor can be 2N2646. The supply can be done with voltages from 6 to 12 V.
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This stethoscope or amplifier for hearing aid using a crystal headset and microphone was found in a...
The normal use of a 4520 as a divide-by-16 counter is shown in Figure bellow. In the normal...