My Circuit

SOFT START MECHANISM FOR L200 VOLTAGE REGULATOR ELECTRONIC DIAGRAM Ic (constant current) is charge capacitor C, where Ic = Vsc/R. The output reaches its nominal value after the time ton. Vo-Vsc=(Ic.ton)/C. ton=C.[(Vo-0.45)/0.45].R = CVoR/0.45. Vo follows the voltage in pin 2 at less than 0.45 volt. It is because voltage of more than 0.45 V can’t be produced between pin 2 and pin 5.

L200 VOLTAGE REGULATOR SOFT START MECHANISM ELECTRONIC DIAGRAM The Vo follows the voltage at pin 2 at less than 0.45 V since a voltage of more than 0.45 V cannot be produced between pins 5 and pins 2. Constant current ic is charge capacitor C, where ic= Vsc/R After the time ton, the output reaches it’s nominal value Vo-Vsc = (Ic.ton)/C ton=C.[(Vo-0.45)/0.45].R = CVoR/0.45

This circuit came about as the result of an  urgent need for a NiMH battery charger. No  suitable dedicated IC being immediately to  hand, the author pressed an L200 regulator and a 4.7 kΩ NTC thermistor into service.  Those components were enough to form the  basis of a charger with a cut-of f condition  based on cell temperature rise rather than  relying on the more common negative delta-V detection. L200 Charger Circuit Diagram :   The circuit uses the L200 with the thermistor in the feedback loop. When ‘cold’ the  output volt age of the regulator is about 1.55 V per cell; when ‘warm’, at a cell temperature of about 35 °C to 40 °C, the out-put voltage is about 1.45 V per cell and the  thermistor has a resistance of about 3.3 kΩ.  This temperature sensing is enough to pre-vent the cells from being overcharged. P1  adjusts the charging voltage, and R2 limits  the charge current to 320 mA. The IC is fitted with a small 20 ...