PICAXE 08M2 Overheat Causes?

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nz-tdm

New Member
I am building a very small circuit for controlling my 3 watt lasers.
It involves a surface-mount picaxe 08m2.

It is very weird what is happening. I know i have made a wiring mistake somewhere as the picaxe is drawing 200mA and gets to untouchable temperatures in seconds.
Heres the weird part, the actual circuit runs perfectly, even drawing 200mA and picaxe probably getting to 100degrees C. For 2 Minutes!

I Made this same circuit on breadboard originally and it used less than 10mA.
What are the causes of picaxe overheat while still functioning?
 
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inglewoodpete

Senior Member
nz-tdm said:
It is very weird what is happening. I know i have made a wiring mistake somewhere as the picaxe is drawing 200mA and gets to untouchable temperatures in seconds.
Heres the weird part, the actual circuit runs perfectly, even drawing 200mA and picaxe probably getting to 100degrees C. For 2 Minutes!

I Made this same circuit on breadboard originally and it used less than 10mA.
What are the causes of picaxe overheat while still functioning?
Click to expand...
A short circuited output causes that sort of heat, unless you have the chip soldered in the wrong way around.

The chip will not last very long at all under those conditions. I hope you have spares. After removing the old chip, thoroughly check your other wiring with a multimeter.

And post some high def photographs of your project and a circuit so we can see what you're trying to do.
 
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Goeytex

Senior Member
The Picaxe is likely blown. And as you said, most likely from a wiring mistake. A "blown" chip can sometimes still partially operate. It is also possible that the code that has set a pin as an output when it was connected directly V+ or to Ground.

However, we cannot make any definite determination without an accurate circuit diagram, your code, and clear close up photos.
 
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manuka

Senior Member
PLEASE urgently do us a favour & detail just why you are apparently working with -gasp- 3 Watt lasers. These would almost "knock asteroids out of orbit" & are near lethal for casual use...

PICAXEs are amazingly robust, & in my 10 years with them (both personally & supervisory) I've not lost a single one. Stan.
 
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MFB

Senior Member
A good way to reduce the chances of blowing chips is to power them from a current limited regulator and, as your 'breadboard original' use less than 10mA, the ubiquitous 100mA regulator should be more than adequate. However, it sounds like you may be powering the PICAXE from the same supply as the Death Ray.
 
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mrburnette

Senior Member
manuka said:
PLEASE urgently do us a favour & detail just why you are apparently working with -gasp- 3 Watt lasers. These would almost "knock asteroids out of orbit" & are near lethal for casual use...
<...> Stan.
Click to expand...
Ah, Stan, such devices are easily acquired in the market today. It may not be legal or smart to mess around with these devices, but available. 2W. Common legal uses are small CNC machines, scientific use, labs, etc. Illegal in U.S. is as a laser pointer.

-Ray
 
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manuka

Senior Member
Ray: I'm indeed aware of the availability & legal uses of burning lasers,but was raising "L.A.S.E.R." (Looking At Source Erases Retina) safety and mischief concerns. NZ allows legal 1mW red laser pointer sales in coin shops, & enough mischief results with even these "toys"...
 
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SAborn

Senior Member
Then some people buy fertilizer for the wrong reasons too, we should not just judge someone just because they employ using a laser.
I to have looked at using one on a CNC machine, and rest assured it would be used with safety and not for death ray purposes.
Although i do admit it would have been good to know what the OP was intending to use the lasers for, and perhaps saved Stans heart from skipping several beats when he read 3W L.A.S.E.R.S
 
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boriz

Senior Member
"...laser strikes..."

I just had a flashback to 70's SciFi

"...He said the results "could have been catastrophic"..."

No shit!. I bought a 200mW green 'LASER pointer' from China for £16. It's great for pointing out stars, but when I use it inside a room, even the dot on the wallpaper is enough to burn a purple stain behind my closed eyes.

Direct into a pilot's eyes?

Regardless of the long term effect on the pilot's vision. 200mW is enough to cause temporary blindness even if it's a brief flash. And a Helicopter pilot needs constant visual references, or he will crash.
 
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Dippy

Moderator
Maybe the OP made a mistake?
Maybe he/she meant 3mW?

I think we'd better wait for another OP visit and a schematic before assuming the OP is experimenting in Fusion power :)
 
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