RE: Heeeeeeeeelp!

["Keith Doxey" <ukha@xxxxxxx>]

With the values of the resistors shown in the circuit there is no way there
should be enough current flowing to make the transistors hot. It sounds
lik=
e
a wrongly connected transistor or transistors.

Check EXACTLY what the writing is on the trannies. BC182, BC182L are
electrically the same NPN transistors but the C & B are reversed.
Likewise
the BC212 and BC212L PNP trannies. I nearly always get them the wrong way
round first time, not least because I meant to get the L variants of both
but somehow  ended up with BC182 and BC212L which makes things
"interesting". Worst of all, I dropped the plastic drawer
containing them
the other day so now have one compartment full of assorted small signal
transistors :-(

Your description of the pinout is confusing. You say that you have C on Pin
1. From memory the two variant are ECB and EBC. The emitter stays in the
same place therefor it sounds as if one is reversed.

Keith

www.diyha.co.uk
www.kat5.tv


> -----Original Message-----
> From: Paul [mailto:groups@xxxxxxx]
> Sent: 23 May 2003 21:02
> To: ukha_d@xxxxxxx
> Subject: RE: [ukha_d] Heeeeeeeeelp!
>=20
>=20
> Thanks very much Dan.
>=20
> Polarity of diodes is OK I think (D1 black band connected to=20
> output of IC1 [pin 1 from the datasheet] D2 black band=20
> connected to base of Q2). D1 voltage =3D 0.6V, D2 voltage =3D 0.97V
>=20
> IC1 - pin 1 (output) =3D -0.1V
> 	Pin 2 (-) =3D -0.05V
>       Pin 3 (+) =3D 0V dead on
>=20
> Output of circuit =3D -0.5V
>=20
> IC1 and both transistors get very hot quite quickly (5 sec or so)
>=20
> I did have one of the transistors connected the wrong way=20
> around (I think) initially when I very first turned it on - I=20
> think they are OK now though but to check - Q1 (BC182L) pin1=20
> =3D E, pin2 =3D C, pin3 =3D B (TO-92 package) - Q2 (BC212) pin1 =3D=20
> C, pin2 =3D B, pin3 =3D E. This info I got from the datasheets.=20
> Is the difference in C-B-E assignment between the two correct?
>=20
> Could I have damaged either the transistors or IC - is it=20
> worth swapping for new ones (or could I damage them if the=20
> circuit is still wrong?).
>=20
> Keith Doxey recommended the substitution of the CA3100 for=20
> the EL2244C. I have the datasheets if that helps?
>=20
> Many thanks for your help!!!
>=20
> Paul.
>=20
> > -----Original Message-----
> > From: Dan [mailto:dtoma@xxxxxxx]
> > Sent: 23 May 2003 19:40
> > To: ukha_d@xxxxxxx
> > Subject: Re: [ukha_d] Heeeeeeeeelp!
> >=20
> > Hi Paul,
> >=20
> > Check the following points:
> > - IC1-pin 2, 3 and 6 to be as near as 0V as possible=20
> (without any input
> > signal)
> > - direct voltage on each of the two diodes(D1 and D2)... it=20
> must be around
> > 0.6V
> > - check if one of the R6 or R7 resistors is not interupted
> > - check the polarity of the two diodes.
> > If something different, send me a mail.
> >=20
> > I don't know EL2244C... you're sure that it is compatible=20
> with CA3100 ?
> > The rest of the substitutions are not important.
> >=20
> > BR,
> > Dan
> >=20
> > ----- Original Message -----
> > From: "Paul" <groups@xxxxxxx>
> > To: <ukha_d@xxxxxxx>
> > Sent: Friday, May 23, 2003 8:39 PM
> > Subject: RE: [ukha_d] Heeeeeeeeelp!
> >=20
> >=20
> > > I'm building the following circuit:
> > >
> > > http://home.maine.rr.com/randylinscott/jan98.htm
> > >
> > > But with the following substitutions:
> > >
> > > IC1 CA3100 (single opamp) changed to EL2244C (dual opamp
package)
> > > Q1 2N3053 (Gen purpose NPN transistor) changed to BC182L
> > > Q2 2N4037 (Gen purpose PNP transistor) changed to BC212
> > > D1 1N914 (small signal Diode) changed to 1N4148
> > >
> > > R3 is a 5K trimmer rather than 2K5 specified (is this a
problem?)
> > >
> > > I'm using an ATX PC PSU as the +12V and -12V source with=20
> the common
> > connection connected to the ground points on the circuit=20
> (is this right?).
> > The PSU has slightly different voltages (+12V is something=20
> like +11.4V
> > and -12V is actually -11.04V).
> > >
> > > When I connect up the circuit, it doesn't work and the=20
> transistors and
> > IC
> > get very hot!
> > >
> > > I'm treble checking the circuit. Any thoughts?
> > >
> > > Thanks,
> > >
> > > Paul.
> > >
> > > > -----Original Message-----
> > > > From: Dan [mailto:dtoma@xxxxxxx]
> > > > Sent: 23 May 2003 18:14
> > > > To: ukha_d@xxxxxxx
> > > > Subject: Re: [ukha_d] Heeeeeeeeelp!
> > > >
> > > > Hi Paul,
> > > >
> > > > Transistor from what???
> > > > Or ...just a simple transistor?
> > > > :-)
> > > > Dan
> > > > ----- Original Message -----
> > > > From: "Paul" <groups@xxxxxxx>
> > > > To: <ukha_d@xxxxxxx>
> > > > Sent: Friday, May 23, 2003 7:46 PM
> > > > Subject: [ukha_d] Heeeeeeeeelp!
> > > >
> > > >
> > > > > Anyone with electronics experience =96 I need help
(please!)
> > > > >
> > > > > My transistors are cooking!
> > > > >
> > > > > Anyone?
> > > > >
> > > > > Paul.
> > > > >
> > > > >
> > > > >
> > > > > ** UKHA2004 BE THERE! ** - start planning now.
> > > > >
> > > > > http://www.automatedhome.co.uk
> > > > > Post message: ukha_d@xxxxxxx
> > > > > Subscribe:  ukha_d-subscribe@xxxxxxx
> > > > > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
> > > > > List owner:  ukha_d-owner@xxxxxxx
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > > http://docs.yahoo.com/info/terms/
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > > ** UKHA2004 BE THERE! ** - start planning now.
> > > >
> > > > http://www.automatedhome.co.uk
> > > > Post message: ukha_d@xxxxxxx
> > > > Subscribe:  ukha_d-subscribe@xxxxxxx
> > > > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
> > > > List owner:  ukha_d-owner@xxxxxxx
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > > ** UKHA2004 BE THERE! ** - start planning now.
> > >
> > > http://www.automatedhome.co.uk
> > > Post message: ukha_d@xxxxxxx
> > > Subscribe:  ukha_d-subscribe@xxxxxxx
> > > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
> > > List owner:  ukha_d-owner@xxxxxxx
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> > >
> >=20
> >=20
> >=20
> >=20
> > ** UKHA2004 BE THERE! ** - start planning now.
> >=20
> > http://www.automatedhome.co.uk
> > Post message: ukha_d@xxxxxxx
> > Subscribe:  ukha_d-subscribe@xxxxxxx
> > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
> > List owner:  ukha_d-owner@xxxxxxx
> >=20
> > Your use of Yahoo! Groups is subject to=20
> http://docs.yahoo.com/info/terms/
>=20
>=20
> ------------------------ Yahoo! Groups Sponsor=20
> ---------------------~-->
> Get A Free Psychic Reading! Your Online Answer To Life's=20
> Important Questions.
> http://us.click.yahoo.com/Lj3uPC/Me7FAA/uetFAA/IBOolB/TM
> --------------------------------------------------------------
> -------~->
>=20
> ** UKHA2004 BE THERE! ** - start planning now.
>=20
> http://www.automatedhome.co.uk=20
> Post message: ukha_d@xxxxxxx=20
> Subscribe:  ukha_d-subscribe@xxxxxxx=20
> Unsubscribe:  ukha_d-unsubscribe@xxxxxxx=20
> List owner:  ukha_d-owner@xxxxxxx=20
>=20
> Your use of Yahoo! Groups is subject to=20
> http://docs.yahoo.com/info/terms/=20
>=20
>=20


[Non-text portions of this message have been removed]