This circuit activates a recorder from the signal obtained from a telephone line in the service. It is used to make automatic call recordings.
This circuit is from September 1984 Radio Electronics. The frequency can be changed by changing C1 and...
This optical coupler for short distances is powered by 12 V which is the voltage of the lamp and...
This circuit was found in a 1980s Intersil documentation. The integrated circuit used is not...