improvment suggesstion for basic stamp

crackticus pots

After finishing my latest robot and the prototype program, I downloaded the program to the stamp with no trouble.·And as·I was about to disconnect the stamp from the download cable.·I noticed a problem with the code. Then after about 30 minutes·I tried to download it a second time this time it said it could not find the·stamp. I checked the cable and the power light and both were fine. After trying several more times without success.·then·I smelled something hot· and·I thought that was weird since·I had nothing on. Except my computer my basic-stamp·and a light. Then I noticed·the basic stamp.·I thought it couldn’t be it because it had nothing connected to it except power and the serial cable. No extra parts or anything that could overload the stamp.·And the power supply was 6Vdc at 500ma, but·I decided to·check·it anyway.·I barley touched it and it gave me a second-degree burn! Nothing was connected to it and there was nothing wrong with it before.
I don’t know what could have happened to it·· but·I suggest that parallax install a temperature sensor on new basic stamps. if it gets to hot. lights a small red LED and shuts off the stamp untill it is cool.

once again this is just a suggestion.

please respond if·you have an idea why.

Post Edited (crackticus pots) : 12/10/2006 11:58:14 PM GMT

Roger Pierson

When you say the power supply was hot, do you mean the Wall-wart, the voltage regulator on whatever board your using, or the internal voltage regulator on the stamp? If you are talking about a voltage regulator, then what is your input voltage to that regulator? For instance, if you have a wall transformer that is putting out 12v and that inputs to a 5v voltage regulator then there is 7 volts that has to be converted to heat. (energy can be neither created nor destroyed....).

Remember PIE. Power in watts (P) is equal to the current (I) times the voltage (E). P= IE

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Roger Pierson
Senior Electronics Technicain
DTI Assoicates

crackticus pots

reply to Roger Pierson:
it is not the walwart that was hot
it was the pic it self (the largest chip actualy on the stamp). the power regulator on the BOE development board was cool to the touch. normaly the PIC is slightly warm, but this was HOT!!!



attached is a picture showing wich chip was hot.

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there are a hundred types of people in the world,

but I dont have time to name them all.

dandreae

What type of circuit did you have connected to it?· Can you take a digital picture and attach it?· This may help us solve the issue.

Thanks,

Dave

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Dave Andreae

Parallax Tech Support·

crackticus pots

Here is the protoboard just as it was the night it quit.
As you can see it has nothing on it. The wires were from an earlier project and had nothing to do with the stamps over heating.
I·have plugged it back in several times and the same thing happens, it gets hot and won't run.
·

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there are a hundred types of people in the world,

but I dont have time to name them all.

tj60647

Hello.· Curious, what is the story on the switch...and can you post a picture of the underside of the board?

terahertz

crackticus pots said...

Here is the protoboard just as it was the night it quit.

WOW, you smoked that board good. Everything is melted with burn marks all over the place. I suspect the copper jumpers all over the breadboard, or it was sitting on a metal surface.

Roger Pierson

That board is looking pretty rough! I sure wouldn't trust it.

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Roger Pierson
Senior Electronics Technicain
DTI Assoicates

crackticus pots

reply to terahertz,·Roger Pierson:

the board it self has nothing wrong with it (other that a loose capacitor and a little dust) nothing is melted or crispied. It looks bad because I do not own a digital camera, so I used a scanner and it turned out pixely. then it went through the jpeg compressor which worsened·it·and·I have high speed dial up high speed and that made it really bad because it compressed it even more.·So it looks bad but it is not. Here is a new photo that shows it better. And no, it was sitting on a Particleboard desk not on·metal.·And if you look closely the jumpers·are connected to nothing. And nothing on the board is shorted. it looks fine but it just heats up and won't run

Reply to tj60647:

The switch is an input selector for the servo jacks. It selects either Vdd or Vin.

But here is a scan any way.

sorry, the photos are in graphics interchange format so they lost·some of there color.



Post Edited (crackticus pots) : 12/11/2006 8:26:22 PM GMT

QuattroRS4

Just a quick question - you said that switch selected either Vin or Vdd . Are you bypassing the on Board regulator with this switch ?

If so - you have a 7v supply and the switch was set to apply the input to Vdd - thats why you smoked it .. Vdd accepts a regulated 5v supply - whereas Vin accepts 6-40v (on the BS2)