Low voltage stabiliser - battery powered voltage regulator

Depending on their condition 1.5 V batteries supply a voltage of 1.2 ... 1.7 V. This circuit can be very useful when a project has to be fed with a constant, low voltage. With an input voltage of 1.2 ... 1.8 V this stabiliser produces a relatively constant voltage of 1.15 V with a maximum load of 5 mA. T2 cuts off at a minimum battery voltage of 1.2 V with a load of 5 mA. The output voltage tends to increase with a higher battery 1 2 1.8V T1 = T2 = BC 172C, BC 549C T3 = BC 252C, BC 559C 1,15 V I voltage, causing T2 to conduct and reducing the base current of T1 and T3 (indirectly), so that the output voltage will remain 1.15 V. The internal impedance of this low voltage supply is 1 to 2 n. The output voltage will only be reduced by 70 mV when changing the battery voltage from 1.8 V to 1.2 V. (ITT application) low voltage stabiliser battery powered voltage regulator