This Power supply sources from 500 to 1,000 mA according the transformar and was found in a publication of the year 1958. The diodes can be now the 1N4004 and the transistor should be mounted on a heatsink.
This circuit was found in a 90s Popular Electronics. The sensors can be common speakers that reach...
This circuit indicates when a 28 V lamp burns, lighting a neon lamp with higher voltage. The...
This circuit was obtained from an American 80's documentation. The operational ones can be...