Re: [uCsimm] Voltage regulator backwards?

From: Robert Vogt IV (robert@arborhost.com)
Date: Sun Aug 05 2001 - 11:12:18 EDT


        Geoffrey,

> > Just finished putting the uCgardener kit together, and I'm getting
> > 1.5 V between pins 7 + 9 (w/ no simm). What is the correct orientation of
> > the voltage regulator (since it isn't clear from the instructions)?
>
> If you're voltage regulator is in a TO-220 case, just line up the outline
> of the case with the silk screening on the board. Both the case and the
> silk screen have a flat side on them you can line up.
>
> Voltage regulators get VERY hot in hurry and pop real fast if you wire it
> up backwards. If it's still working, but outputting the incorrect
> voltage, the regulator is probably either defective, or there's a problem
> somewhere else in the circuit (e.g. solder bridges).

        Ok... the TO-220 case is the solid-state transistor-like case? I
lined up the regulator w/ the silk screening and pulled the center pin
backwards to go in the middle hole, then soldered it all in... I'm
guessing that's correct?

        And yes - its VERY hot... Nearly burned my finger... I'm using a
variable Voltage Radio Shack power supply - I get ~1.5 V from it set at
4.5 and 6 V. Is it possible other elements of the circuit are
incorrect? I'm going to try to find a picture of an assembled board so I
can double check everything. And am I correct in assuming the 0.1uF
capactitor has no preferred orientation?

        Thanks in advance.

                        Sincerely,

                        Robert Vogt IV
                        ArborHost

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