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How to stop 555 IC from heating up?

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sr13579

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I was trying to make a LED flasher with 555 IC. Then I thought how about I set a transformer with the output-ground pins. And I also reduced the resistance between 7 and 6 pin. And I am getting a 31V AC output from my transformer output panel. Looks like it is possible to make an inverter with this. But I can't reduce the heat of IC. Is there any way to reduce the heating?
There is one image of the curcuit attached.
 

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dknguyen

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I'm not really sure what you mean in the rest of your post though because no 555 timer variant can handle past 15V AFAIK.

But to reduce heating in general, instead of driving the LED (or whatever load) directly from the 555 timer, use the 555 timer to drive a transistor which drives the LED. This also lets the 555 timer drive loads with higher voltages and currents than it can handle as long as you find transistor that can handle the higher voltage across it's sourge-drain or collector-emitter and can also be driven from it's gate/base by the 555 timer, then you can drive a load with whatever voltage you want while running the 555 timer within it's limits.

Not unlike this:
http://www.fiz-ix.com/wp-content/uploads/2012/11/NPN-Switch-2.png
 
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sr13579

Member
I'm not really sure what you mean in the rest of your post though because no 555 timer variant can handle past 15V AFAIK.

But to reduce heating in general, instead of driving the LED (or whatever load) directly from the 555 timer, use the 555 timer to drive a transistor which drives the LED. This also lets the 555 timer drive loads with higher voltages and currents than it can handle as long as you find transistor that can handle the higher voltage across it's sourge-drain or collector-emitter and can also be driven from it's gate/base by the 555 timer, then you can drive a load with whatever voltage you want while running the 555 timer within it's limits.

Not unlike this:
http://www.fiz-ix.com/wp-content/uploads/2012/11/NPN-Switch-2.png
I am trying to make an inverter circuit. With transistor I can drive LED. But how am I supposed to get a full square-wave with transistor and use it with a transformer?
 

alec_t

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Is there any way to reduce the heating?
Yes: stop abusing the 555 :rolleyes:. It's maximum rated current from pin 3 is 200mA, so with a 9V supply the load it can safely drive should be about 40Ω or more. The transformer winding resistance is obviously much less than that!
I second the post #2 suggestion to use a transistor.
 

sr13579

Member
Yes: stop abusing the 555 :rolleyes:. It's maximum rated current from pin 3 is 200mA, so with a 9V supply the load it can safely drive should be about 40Ω or more. The transformer winding resistance is obviously much less than that!
I second the post #2 suggestion to use a transistor.
Okay Sir. I am sorry for 555 abusing!
 

dknguyen

Well-Known Member
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I am trying to make an inverter circuit. With transistor I can drive LED. But how am I supposed to get a full square-wave with transistor and use it with a transformer?
I don't have enough information (or sleep to be honest) to answer your question farther than what I've already given. Use a transistor to drive the transformer to do whatever it is you want to do. The first most basic thing to do is to stick the transformer where the LED and resistor would be along with the transistor. Just make sure you're switching at the right frequency so not too much DC flows through the transformer windings and give the transformer a load.
 

audioguru

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If your 555 was driving a transformer then why did you post a schematic of it driving an LED with a current of only 6mA?
Seeing your schematic I was going to ask if it is a fake Chinese 555 that you got from ebay.
 

MikeMl

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Most Helpful Member
Only an overloaded 555 heats up!
 
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