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[help]Micro-seven segment problem

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electronproton

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current booster 7805

Hi guys..

I'm designing a safety deposit box with 6 seven segment as display..

I drive the seven segments using pnp transistor.. but the 7805 become very hot when the seven segments are ON..

can I use the 12v power supply to supply the seven segments?
what should I use

can someone help me?

thx

DnL
 

high current 7805 2n3055

It is because ur 7segment draws more current.

Try using another 7805 in parallel
or a current booster.

BTW do you have a heat sink for 7805?

Regards
Nandhu
 

7805 current boost transistor

i don't use heat sink..
coz i want it to be small..

if i use 2 7805, then one of the 7805 which drive the seven segments will the hot right?

BTW what is current booster..?

thx
 

Provide heat sink.
Probably it is not able to provide sufficient current when all the displays on,with around 7V drop across itself.That could be a problem.
 

electronproton said:
i don't use heat sink..
coz i want it to be small..

if i use 2 7805, then one of the 7805 which drive the seven segments will the hot right?

BTW what is current booster..?

thx
Click to expand...

Not providing heatsink to keep the board small is not good design nor practice.
You should provide heatsinks wherever necessary.

regarding current booster
google high current regulator
you will find 7805 circuit with 2n3055 or such transistors.

Regards
Nandhu
 

electronproton said:
i don't use heat sink..
coz i want it to be small..

if i use 2 7805, then one of the 7805 which drive the seven segments will the hot right?

BTW what is current booster..?

thx
Click to expand...
Its better if you use heatsink other wise any time the regulator will burn,, why dont you use 7 segment display from direct supply without 7805?? I mean, use 7805 for the controller circuit and supply 7 segment direct from rectifier. use rectifier upto 9v - 10v.
regards
 

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