Article View: sci.physics
Article #15455Re: Query - How valves and transistors work
From: Duncan Barclay
Date: Sat, 02 Jan 1999 00:00
Date: Sat, 02 Jan 1999 00:00
36 lines
2976 bytes
2976 bytes
In article <76ja03$gud$1@news-2.news.gte.net>, Doug <do@not.spam> writes: > Duncan Barclay wrote: >> >> This thread started with someone (Nightjar) asking how they worked. >> Out of four replies I followed up on one thread was not asking how > > Getting back to NightJar ... > > BJTs can be thought of a CURRENT CONTROLLING DEVICES > and valves can be thought of VOLTAGE CONTROLLING DEVICES. > > BJTs offer variations in the emitter-base CURRENT controlling > variations in emitter-collector CURRENT. Ahhhhhhhhhhhhhhhhhhhhhhhhhhh I give up. This is NOT correct. How does this explain the way a long-tailed pair works? A BJT allows you to control a current by varying the base emitter voltage. Certain circuit configurations make it appear that you can control the collector current by changing the base current. But as this ratio varies with temperature, device, process, batch, which direction the circuit board is facing, it's not very useful. Duncan -- ________________________________________________________________________ Duncan Barclay | God smiles upon the little children, dmlb@ragnet.demon.co.uk | the alcoholics, and the permanently stoned. ________________________________________________________________________
Technical Details
Message-ID:
<76jqau$ltt$1@computer.my.domain>Path:
arc1-ca.pugleaf.net!unknown!not-for-mailReferences:
<368691bc.0@stargazer.actinet.net> <76b08g$jo4$1@news-1.news.gte.net> <76b8i0$rqm$1@computer.my.domain> <fuNEGVAumei2EwR5@jmwa.demon.co.uk> <76dss3$fhq$1@computer.my.domain> <d1dLzCAjKri2EwAr@jmwa.demon.co.uk> <76ibj9$rhc$1@computer.my.domain> <76ja03$gud$1@news-2.news.gte.net>Show Full Headers
Complete Article Headers
X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fcc1a,6f59d673fceaf3aa X-Google-Attributes: gidfcc1a,public X-Google-Thread: 107d45,6f59d673fceaf3aa X-Google-Attributes: gid107d45,public X-Google-Thread: 1110fe,6f59d673fceaf3aa X-Google-Attributes: gid1110fe,public X-Google-Thread: 112d1e,6f59d673fceaf3aa X-Google-Attributes: gid112d1e,public X-Google-Thread: 10b271,6f59d673fceaf3aa X-Google-Attributes: gid10b271,public X-Google-Thread: 1118be,6f59d673fceaf3aa X-Google-Attributes: gid1118be,public X-Google-Thread: 111d0a,6f59d673fceaf3aa X-Google-Attributes: gid111d0a,public X-Google-Thread: 114713,6f59d673fceaf3aa X-Google-Attributes: gid114713,public From: dmlb@ragnet.demon.co.uk (Duncan Barclay) Subject: Re: Query - How valves and transistors work Date: 1999/01/02 Message-ID: <76jqau$ltt$1@computer.my.domain> X-Deja-AN: 427928818 Distribution: world X-NNTP-Posting-Host: ragnet.demon.co.uk:158.152.46.40 References: <368691bc.0@stargazer.actinet.net> <76b08g$jo4$1@news-1.news.gte.net> <76b8i0$rqm$1@computer.my.domain> <fuNEGVAumei2EwR5@jmwa.demon.co.uk> <76dss3$fhq$1@computer.my.domain> <d1dLzCAjKri2EwAr@jmwa.demon.co.uk> <76ibj9$rhc$1@computer.my.domain> <76ja03$gud$1@news-2.news.gte.net> Content-Type: text/plain; charset=us-ascii X-Complaints-To: abuse@demon.net X-Trace: news.demon.co.uk 915258718 nnrp-04:14454 NO-IDENT ragnet.demon.co.uk:158.152.46.40 Organization: Ragnet, a small network of machines at Raggy's home. Mime-Version: 1.0 Newsgroups: sci.physics,fj.sci.physics,sci.physics.electromag,tnn.physics,news.electronics.basics,sci.electronics.basics,sci.electronics.components,sci.electronics.design,sci.electronics.misc