dc voltage regulator

This design was generated as part of a remote weather station project. One of the requirements of the design is that it have a solar-powered supply with rechargeable batteries. This design is based on a photovoltaic array available from Radio Shack called a BatterySAVER (part number 980-1045). It was designed to charge your car battery [...]

The 15v zener is fed via the 4K7 resistor from the input. With 0.6v across the base - emitter of the PNP transistor, this establishes a voltage of 14.4 across the 3K3, so there must be a current of nearly 4.4mA through the 3K3. This current is available to feed the emitter of the transistor [...]

A 10,000uF/50V electrolytic capacitor completes the filtering of the 28.8V. Yep, C1 is a real clunker. You can use larger if you like, just watch it when you power up. Without a ‘power-up’ delay circuit of sorts it will probably blow-up the 723 if the capacitor (C1) is too-large. The DC voltage coming from BR1 [...]