Voltage stabilising circuit for camera - uses zener diode and constant current stage with low current consumption

摘要

A Zener diode based circuit provides voltage stabilisation that requires only a small packaging volume and is therefore particularly suited to camera applications. The stabilised voltage supply is suitable for controlling the variation in camera aperture using a stepping motor. The stabilising circuit consists of a Zene diode operating together with a high resistance and a field effect transistor. The resistance is sized to the Zener diode to minimise the current consumption.