i am using this circuit------working ---------
https://hassanulmakers.files.wordpress.com/2014/12/lm317-5a-variable-adjustable-supply-circuit.gif
-------circuit exact same as above---few----modifications--done----
i am using 0-40 v ac transformer---5a---using tip 3055 plastic package----10 ohm/10 w resistor----10 k potentiometer
------sharing current concept lm 317 and tip 3055----------
As current starts to flow through the 10 ohm resistor, a voltage drop will appear across it. When this voltage drop is higher than 0.6 volts, the 2N3055 starts to conduct and supply current to the output of the power supply. This starts happening when the IC LM317 is outputting 60 mA, as ohm's law show us: 0.6/10= 0.06 a . so lm 317 outputs only 60 ma while rest current is handled by 2n3055 or mje 3055 or tip 3055 or npn transistor.power dissipated by 10 ohm resistor = 0.6*0.6/10=0.036 w.
-----------------i have few queries------------------
1---------is current sharing between lm 317 and tip 3055 okay ---in future i will put 8 pcs more tip 3055 with small output equal balancing resistors as 0.22/5 w for equal sharing of power between transistors ?
2--------------i want add constant current --in circuit---potentiometer value/watt( current adjustment should be sensitive i mean i can adjust from 0.5 to 0.78 a)----what extra modification circuit needed---a diagram would be very helpful if possible--------?
3-----------weird problem----whenever i connect 10 k pot----it burns out--why-----using smallest wattage pot--i guess 1/2 w pot-----how exactly do i connect 3 legs of this kind of pot--a figure would be helpful-- ?
--https://www.build-electronic-circuits.com/wp-content/uploads/2015/11/potentiometer.jpg
----------------------thank you------------------
https://hassanulmakers.files.wordpress.com/2014/12/lm317-5a-variable-adjustable-supply-circuit.gif
-------circuit exact same as above---few----modifications--done----
i am using 0-40 v ac transformer---5a---using tip 3055 plastic package----10 ohm/10 w resistor----10 k potentiometer
------sharing current concept lm 317 and tip 3055----------
As current starts to flow through the 10 ohm resistor, a voltage drop will appear across it. When this voltage drop is higher than 0.6 volts, the 2N3055 starts to conduct and supply current to the output of the power supply. This starts happening when the IC LM317 is outputting 60 mA, as ohm's law show us: 0.6/10= 0.06 a . so lm 317 outputs only 60 ma while rest current is handled by 2n3055 or mje 3055 or tip 3055 or npn transistor.power dissipated by 10 ohm resistor = 0.6*0.6/10=0.036 w.
-----------------i have few queries------------------
1---------is current sharing between lm 317 and tip 3055 okay ---in future i will put 8 pcs more tip 3055 with small output equal balancing resistors as 0.22/5 w for equal sharing of power between transistors ?
2--------------i want add constant current --in circuit---potentiometer value/watt( current adjustment should be sensitive i mean i can adjust from 0.5 to 0.78 a)----what extra modification circuit needed---a diagram would be very helpful if possible--------?
3-----------weird problem----whenever i connect 10 k pot----it burns out--why-----using smallest wattage pot--i guess 1/2 w pot-----how exactly do i connect 3 legs of this kind of pot--a figure would be helpful-- ?
--https://www.build-electronic-circuits.com/wp-content/uploads/2015/11/potentiometer.jpg
----------------------thank you------------------
