> Bob Ammerman wrote: > > > ----- Original Message ----- > > From: "Thomas C. Sefranek" > > To: > > Sent: Sunday, June 02, 2002 6:24 AM > > Subject: Re: [EE]:Transistor Help!!!!!!!! > > > > > On 2 Jun 2002 at 3:08, Ed Heath wrote: > > > > > > > I have a TO220 transistor marked "69-526" it has a Motorola > > > > stamp. > > > > > > THis is an in-house number (inventory control). > > > The whole intention is to hide the identity of the device being used. > > > It reads 1969- lot# 526 design. > > > The parameters will not be revealed by Motorola without written > > > consent of the origional contractor. > > > > But if the statement that it is from a 1969 design is correct it does limit > > the specifications to what could be done back then... probably pretty > > limited by todays standards. > > O.K.... > > And this would just re-enforce my later sentance about using a generic > device... > So what point are you making that I'm too dull to get? > (It is a lazy Sunday afternoon...) No point at all. Your idea for a generic solution is excellent. All I am saying is that you can probably use a lower-spec generic replacement if you can come up with limits on the device in question. Some ways to determine such limits: 1: As noted in my prior post: by knowing what was available when the device was built. 2: Voltage specs can be determined by the max voltage in the circuit (with an appropriate 'safety' multiplier of course). 3: Current specs can be determined by series components. EG: if the device is in serieas with a 0.1 ohm 10W resisistor you know that it has at most 10A current flowing in it. Bob Ammerman RAm Systems -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics