This circuit for currents from 500 mA to 1.5 A was found on a Ham Radio from the 90s. R4 determines the current in the load under test. Transistors must be equipped with radiators.
Other operational amplifiers series, such as MC34072, MC34074, MC35071, MC35072, MC35074 d MC33071...
This transmitter emits signals in the FM range, reaching a few meters away. The modulation...
The consumption of this circuit in the standby condition is only 1 uA. The circuit must be...