Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime powered by a 6 V continuous voltage. The transistor can be a BD136.
This experimental receiver was found in an English publication in 1979. It can receive medium-wave...
January 2017 – The bq35100 integrated circuit, a charge monitor and EOS for non-rechargeable...
This configuration, found several times on this site and in other articles, can generate...