get an ordinary pc power cord, cut mo. Be sure to identify kung alin and ground since you can do away with this. All you need are the poles (+ & -). Get an ordinary extension cord. Kung built-in yung plug, putulin mo. Then pagdugtungin yun dalawang cords (pc power cord & extn cord). Apply electrical tape to seal. Voila!

Used to do that sa dating job ko, we have monitoring setups of 50 tv stations (each setup has tv & 4 vcr). Ala ako makuha cheaper UPS kaya pinatulan ko yung mga lumabas na small UPS na pang-PC (anyways, may genset naman kami, what i need that time is kahit around 10 secs lang, ung kasi ang delay ko from Meralco to Genset).