Speakerplans.com Homepage
Forum Home Forum Home > Other Chat > Golden oldies
  New Posts New Posts RSS Feed - Haze Caravelle (barn find!)
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Haze Caravelle (barn find!)

 Post Reply Post Reply Page  <123
Author
Message
kedwardsleisure View Drop Down
Old Croc
Old Croc


Joined: 20 January 2009
Location: Staffordshire
Status: Offline
Points: 4229
Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 28 November 2018 at 4:23pm
are those resistors burnt out by the fuse?
K. Edwards Electronics Engineers

North Staffordshire

Back to Top
odc04r View Drop Down
Old Croc
Old Croc
Avatar

Joined: 12 July 2006
Location: Sarfampton
Status: Offline
Points: 5017
Post Options Post Options   Thanks (0) Thanks(0)   Quote odc04r Quote  Post ReplyReply Direct Link To This Post Posted: 29 November 2018 at 9:51am
I thought possible the same, but after zooming in the markings are legible. I think for whatever reason they are just black resistors.

If you draw out the circuit and indicate components then post it up here+DIYAudio you will end up with many suggestions regarding circuit improvements/stability/ability to drive the putput stage etc. Driving a pair of output transistors should not be an issue for a single driver but some attention may have to be paid to heatsinking/bias.




Edited by odc04r - 29 November 2018 at 9:52am
Back to Top
Pinyorouk View Drop Down
Registered User
Registered User


Joined: 31 January 2011
Status: Offline
Points: 434
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pinyorouk Quote  Post ReplyReply Direct Link To This Post Posted: 29 November 2018 at 3:44pm
Usaually if there are 2 output transtors it is only good for 8 ohm operation minimum. With 4 output transistors, 4 ohm operation minimum. That was the case with amps I worked on in the 80's.

Edited by Pinyorouk - 29 November 2018 at 4:45pm
Back to Top
vital spark View Drop Down
Registered User
Registered User


Joined: 16 November 2018
Status: Offline
Points: 11
Post Options Post Options   Thanks (0) Thanks(0)   Quote vital spark Quote  Post ReplyReply Direct Link To This Post Posted: 29 November 2018 at 10:29pm
hi, I actually thought the same about those resistors, since there’s a little heat damage against the fuse. I removed them and tested individually. They are resistors, and a bit of searching their part numbers etc and they are 0.47 ohm fused resistors. Very low resistance, so assume they are effectively just a fuse?

Progressing along with the rest. I’m 50% there with a circuit diagram on the first, and with the milder weather I’m finishing painting the transit case. Also lost two starboard side tyres commuting tonight, to a pothole,  so that’s a bit of a setback! 



Edited by vital spark - 29 November 2018 at 10:33pm
Back to Top
odc04r View Drop Down
Old Croc
Old Croc
Avatar

Joined: 12 July 2006
Location: Sarfampton
Status: Offline
Points: 5017
Post Options Post Options   Thanks (0) Thanks(0)   Quote odc04r Quote  Post ReplyReply Direct Link To This Post Posted: 30 November 2018 at 11:48am
Originally posted by vital spark vital spark wrote:

hi, I actually thought the same about those resistors, since there’s a little heat damage against the fuse. I removed them and tested individually. They are resistors, and a bit of searching their part numbers etc and they are 0.47 ohm fused resistors. Very low resistance, so assume they are effectively just a fuse?

Progressing along with the rest. I’m 50% there with a circuit diagram on the first, and with the milder weather I’m finishing painting the transit case. Also lost two starboard side tyres commuting tonight, to a pothole,  so that’s a bit of a setback! 



They're possibly both fuses and also act as emitter balancing resistors when using multiple output transistors to make sure currents stay roughly balanced.

Good work on the diagram, be interested to see it. I'm sure it is a very classic circuit
Back to Top
 Post Reply Post Reply Page  <123
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.063 seconds.