In a telecommunication unit attached to a telephone line, power is provided by taking power from the telephone line when the unit is off-hook. When the unit remains on-hook, power is maintained to circuitry in the unit by a charge stored in a capacitor. When the capacitor's charge is reduced to a level no longer able to sustain operation of the unit, the unit is briefly taken off-hook, allowing the capacitor to recharge. Charge control of the capacitor is performed either by discrete circuitry or by a microcontroller, and further includes logic provisions preventing the unit from remaining off-hook for an unduly long period of time.