3 TO 30 Volt 3 Ampere DC Power Supply

Parts listR1 = 8.2KR2 = 2.2KR3 = 680RR4 = 1KR5 = 82KR6 = 0.18R/5WC1 = 470pC2 = 100nF-63VC3 = 100nF-63VC4 = 100uF-63VC5 = 10KuF-60VD1-D6 = 6.6AQ1 = MJ3001 (Darligton)IC1 = UA723DSpecifications Overload protected Short-circuit stable Output current: max. 3A Output ripple voltage: 0.5mV Output voltage: adjustable from 3 to 30V, stabilized Input voltage: 9 to 30V AC (depending on the desired output voltage)Assembling into a housing Depending on the transformer used, one may chose one of two housings If a metal housing is used, it must be earthed for security purposes. Make sure the cooling body does not touch the housing. This might cause a short circuit. When mounting a toroidal transformer, it must be seen to that the fixation bolt does not touch the cover. This might cause the burning of the transformer If the circuit is to be integrated into another housing, it must be provided with ventilation holes (one may make these holes oneself), necessary for the release of the heat developed.Notes Connect a voltage meter to the points GND and +OUT and adjust RV1 until the desired output voltage is reached. Apply some thermo-conducting paste to the bottom side of the transistor and mount it on the heatsink. If you need 3-8 volt then R2 will be 5.6K If you need more than 8 volts then the R2 will be 2.2K Suitable transformer 30vAC at 120VA