hi thankyou so much. i think there is misunderstanding my camcoder not need 7.5 A but it is a capacity of battery like motorcycle battery. i use itu because i want using my camcoder for long time, my camcoder battery is only 1.1A and it can be approx. 80 minutes so i choose to convert my 12V 7AH battery to voltage level of camcoder. my camcoder general spec: power requirements : 8.4V (1.5A) power consumtions on recording (LCD) : 5.9 W my question is : is it enough if i only use adjustable voltage regulator with lm317T like this schematic