The Poor Serbian Man's Optical Attenuator

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Sorry as I still have another doubt, the split power supply which use LM317 for +ve and LM337 for -ve rails constant current source has different current output, although I constructed them with 22Ohms current limit resistor, but I got ~ 46mA at +ve rail and ONLY ~ 16 mA at -ve rail. By calculation I shud get ~ 56mA from each rail.. why this happen ? :-( tot LM337 faulty, but still the same even replaced with new IC.. I measure the current by connecting 100 Ohms resistor ( serial to ammeter)
and shorted the output ( LM 337 / LM317 ) reference to ground.. thanks
 
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