need help for Dual-rail Variable DC Power Supply-Circuit Diagram

[joshua.svn]

This is Dual-rail Variable DC Power Supply-Circuit Diagram, working well and the transistors
bc337 and bc327 . but when i am using 100 ma from the supply transistors getting heat.

i tried with power transistors like TIP127 , TIP122 they are also getting heat more than
bc337 and bc327 and need heat sinks. for 150 ma using them is not a good idea..

i need 150 ma. for

so any one please suggest some desecrate components for the above circuit they will not get
hot.
input voltage is 10 volts out put i am getting -5 and +5. load i am using seven segment display
icl 7107 which is drawing 100 ma.

and the ic is tlo71 ...

any circuit identical with same concept are welcome... with regulators are any other method.



Circuit Diagram: attached

regards
svn.

 

[alec_t]

With that circuit if your supplies are, for example, +6V/-6V then for 100mA load current one or other transistor will be dissipating 6V x 100mA = 600mW. So it will get hot. For 150mA the power loss rises to 900mW. Whatever type of transistor you use it will suffer a similar power loss and get hot unless it's a very large type or is heatsinked.

 

[ericgibbs]

hi,
What load current are you drawing from the +Vout and the -Vout, also what is the OPA type and the input voltage.?

 

[joshua.svn]

input voltage is 10 volts out put i am getting -5 and +5. load i am using seven segment display
icl 7107 which is drawing 100 ma.

and the ic is tlo71 ...

 

[ericgibbs]

input voltage is 10 volts out put i am getting -5 and +5. load i am using seven segment display
icl 7107 which is drawing 100 ma.

and the ic is tlo71 ...

hi,
When the TIP's are getting hot, are they both hot or just one.??

You asked on your other thread for a +/-9V supply at 500mA.

This type of power splitter works better [ lower heating of the power transistors] when the current drawn by the +Vout is the same as the current drawn by the -Vout.

E