Jump to content
Electronics-Lab.com Community
tjolle62

Overload Protector A16 ???

Recommended Posts

In a few circuit diagrams i have they refer to a what seems to me is a transistor
with B C E as a overload protector and with number A16 and i have looked for a few hours on the net and i can't find anything on this little fellow,
Anyone knows what I'm looking for and wanna share that info Please ....

Come on !! 48 visits !! some one must know what it is !!! PNP is it also...........

Share this post


Link to post
Share on other sites

It could be used as a switch, amplifier or (as you've said) part of a current limiting circuit.

Bipolar transistors have so many applications that it's impossible to tell you what it's doing from what you've said. For example if I asked you "I've seen a flat head screw; what's it holding together?", how could you know the answer?

If you post a picture I might be able to tell you but even then the only way is to post a schematic.

Share this post


Link to post
Share on other sites

Hello Hero and thnx for the reply in this matter !!
That thing with the screw was great thou im a old auto tech and heard almost everything in that  vicinity,,
Im sorry if my question was incomplete but i submit a copy on this schematic now.

Power-supply-A16-mj2955-for-digital.jpg

Share this post


Link to post
Share on other sites

Yes, it's being used as a current limiter.

The 2N2955 is a booster transistor, when the voltage across the 50R resistor (or is it 60R? the schematic is too fuzzy) exceeds about 0.7V it turns on, allowing current to bypass  the regulator.

A16 is acting as a current limiter, when the across the 0.1R resistor exceeds 0.7V it turns on which pulls the base of the 2N2955 closer to the emitter, causing it to turn off.

What output voltage do you want to get out of this?

With a 9V transformer, the maximum output voltage is 5V.

How much current do you want to draw?

The transformer is rated to 2A but with the values shown, the current limit will be about 7A.

Share this post


Link to post
Share on other sites

Now we getting somewhere !!
In my mind i had a theory that if i wanna use for example a car battery as feed and
it would be great if i could draw 5V - 3-5A out of this circuit.
I'm sure that it is better solutions for this task out there but i got curious about
that A16 thing !!!

Share this post


Link to post
Share on other sites

Now we getting somewhere !!

Yes, you'll nevery get any help until you give enough information.
In my mind i had a theory that if i wanna use for example a car battery as feed and
it would be great if i could draw 5V - 3-5A out of this circuit.
I'm sure that it is better solutions for this task out there but i got curious about
that A16 thing !!!
Yes, it will work although it's a very crude and inefficient solution, a switching regulator is better idea.

Share this post


Link to post
Share on other sites

Sorry if my question was little fuzzy before but after 12 years my english has become a bit rusty !!
like i wrote previous so was i more curious in this A16 - 1A16 model of pnp trans,
just putting together a piggy back TIP2955 on a LM317 and it works great,
Thank you Hero,
//Kjell /Sweden.

Share this post


Link to post
Share on other sites

The lack of a schematic was a greater barrier to getting help than your poor English.

I couldn't find much information about 1A16 on the Internet. I imagine that any PNP transistor rated to 1.5A will do.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...