Offset Compensated Emitter-follower...

mikeks · 4th June 2006, 08:16 PM

See attached...

darkfenriz · 4th June 2006, 08:50 PM

Looks like variation on Sziklai connection. How does it perform?

mikeks · 4th June 2006, 08:56 PM

Quote:

Originally posted by darkfenriz
Looks like variation on Sziklai connection.

Nope...

Quote:

Originally posted by darkfenriz

How does it perform?

Q1 is the emitter follower...Q2 is the diode which provides offset compensation....The current mirror provides bias for the diode....probably good idea to bypss it with 1uF to the +supply rail.

Ultima Thule · 4th June 2006, 09:19 PM

Mike,

where do you find it's application?
It seem to have only current amplification, is it much better than an emitter follower for instance except that a single emitter follower introduce an offset?

Cheers Michael

mikeks · 4th June 2006, 09:26 PM

Quote:

Originally posted by Ultima Thule
.....an emitter follower........except that a single emitter follower introduce an offset?

Cheers Michael

Yup...

sawreyrw · 4th June 2006, 09:32 PM

Mike,

I'm pretty sure this circuit will burn up in a few msec, if you actually build one. The current through Q7 will be over .3 amps, so it's power dissapation will be over .3*22=6.6 watts.

Rick

poobah · 4th June 2006, 09:32 PM

Any significant output current will imbalance the emitter currents and therefore the Vbe.

It generally not the offset in emitter followers that upsets things... rather it is the fact the offset is nonlinear function of current.

Am I missing something here?

mikeks · 4th June 2006, 09:33 PM

Quote:

Originally posted by sawreyrw
Mike,

I'm pretty sure this circuit will burn up in a few msec, if you actually build one. The current through Q7 will be over .3 amps, so it's power dissapation will be over .3*22=6.6 watts.

Rick

Where did you get 0.3Amps???

mikeks · 4th June 2006, 09:34 PM

Quote:

Originally posted by poobah
Any significant output current will imbalance the emitter currents and therefore the Vbe.

It generally not the offset in emitter followers that upsets things... rather it is the fact the offset is nonlinear function of current.

Am I missing something here?

Try it...

Ultima Thule · 4th June 2006, 09:46 PM

..and this one not good enough?

EDIT: Had to redraw, was too quick..

4th June 2006, 09:19 PM	#4
Ultima Thule diyAudio Member Join Date: Jan 2004 Location: Koskenkorva Land	Mike, where do you find it's application? It seem to have only current amplification, is it much better than an emitter follower for instance except that a single emitter follower introduce an offset? Cheers Michael __________________ "If transistors are blueberries and FETs are strawberries, then tubes must be.. pears" Michael 29th January 2010

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Has anyone ever tried a Beta Enhanced emitter follower VAS??	vynuhl.addict	Solid State	27	24th April 2010 09:56 AM
Complex Emitter follower	Banfi T.	Solid State	104	1st April 2003 10:05 PM
Help a nOOb out with an emitter-follower...	EchoWars	Solid State	8	8th January 2003 09:40 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

4th June 2006, 08:50 PM	#2
darkfenriz diyAudio Member Join Date: Jun 2004 Location: Warsaw	Looks like variation on Sziklai connection. How does it perform?

4th June 2006, 09:32 PM	#6
sawreyrw diyAudio Member Join Date: Apr 2006 Location: Minnesota	Mike, I'm pretty sure this circuit will burn up in a few msec, if you actually build one. The current through Q7 will be over .3 amps, so it's power dissapation will be over .3*22=6.6 watts. Rick

4th June 2006, 09:32 PM	#7
poobah diyAudio Member Join Date: Nov 2005	Any significant output current will imbalance the emitter currents and therefore the Vbe. It generally not the offset in emitter followers that upsets things... rather it is the fact the offset is nonlinear function of current. Am I missing something here?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)