This shunt voltage regulator was found in an Electronic Design from the 90's. The power transistor must be in accordance with the load current and must be equipped with a heat sink.
This source was found in a 1982 American publication, but can be easily assembled using 2N2995 (PNP...
This receiver can operate with the transmitters shown in previous articles and even others...
We got this circuit in an old 1983 publication, but it can be fitted with equivalent transistors. For Q1...