How low can it go?

摘要

Once you're no longer baffled by the supply voltages at which modern computer processors and memories work, it's a challenge to check how far a supply voltage of an all-analogue electronic circuit can be lowered with the circuit remaining operational. The circuit under test, shown here, is an ordinary astable multivibrator built from a pair of PNP transistors and a piezo beeper to signal that the electronics is still working. The operation of the circuit is checked with an oscilloscope as well, because at low supply voltages the beeper is likely to produce a very low sound level. The circuit has been tested and the response noted.