Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Login
Problems vid Placid BP - Unable to adjust voltage on negative side
Options
View
Go to last post Go to first unread
Previous Topic Next Topic
Crumboo  
#1 Posted : Tuesday, March 25, 2014 5:47:45 PM(UTC)
Crumboo

Rank: Member

Groups: Member
Joined: 3/17/2012(UTC)
Posts: 15

Thanks: 4 times
Hi,

I recently put together my Placid BP for powering 4xIVY (well, the same schematics and parts but home made pcb:s).

I successfully adjusted the voltage (+15V) and shunt current (50 mA) on the positive side. But on the negative side I can't get the right values. I cannot get more (or less as it's negative) than -10V.

Also, I noted that while both heat-sinks get slightly warm on the positive side, only one of them gets warm on the negative side (the other one stays cold).

What more can I check in order to identify the problem? All LED's lights up. The AC input is at 16V on both rails.

Best regards,

Mattias
Back to top

Wanna join the discussion?! Login to your Twisted Pear Audio Support forum accountor Register a new forum account.
Back to top  
Brian Donegan  
#2 Posted : Tuesday, March 25, 2014 6:20:56 PM(UTC)
Brian Donegan

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
Most common issues:

  • Cold/bad solderjoint(s)
    Transposed small signal transistors
    Reversed diode (D1A/B)


Give those a look and report back. Photos often are very helpful.

Also, do you have the supply connected to a load? Have you tried with no load?
Back to top
WWW
Crumboo  
#3 Posted : Wednesday, March 26, 2014 8:10:38 PM(UTC)
Crumboo

Rank: Member

Groups: Member
Joined: 3/17/2012(UTC)
Posts: 15

Thanks: 4 times
Thanks Brian - it was probably some solder joint. I reworked them and now the unit work as it should!:)
Back to top
dsolodov  
#4 Posted : Saturday, March 29, 2014 2:00:34 AM(UTC)
dsolodov

Rank: Member

Groups: Member
Joined: 8/22/2010(UTC)
Posts: 38
United States

Thanks: 14 times
I have a question on temperature of QN1 and QN2 on Placid HD v.1.0. I built a couple of them, and tried to run both open sitting on a table. On both PSUs the temperature of QN1 (~51C-> 123F) is about 20C (36F) higher than the T (31C -> 87F) on QN2. I used Fluke 62 Mini IR thermometer after about 1/2 hour of operation. Is such temperature differential to be expected?

[TP_VIN+, TP_CCS+] => ~500mVDC
[TP_OUT+, TP_SHUNT+] => ~45mVDC
Vout => ~5.25VDC
Back to top
avr300  
#5 Posted : Saturday, March 29, 2014 8:06:01 AM(UTC)
avr300

Rank: Member

Groups: Member
Joined: 6/17/2008(UTC)
Posts: 921
Denmark

Thanks: 1 times
Was thanked: 70 time(s) in 69 post(s)
It normail
Back to top
thanks 1 user thanked avr300 for this useful post.
dsolodov on 3/30/2014(UTC)
Rss Feed  Atom Feed
Users browsing this topic
GuestUser (5)
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Youtube
Copyright © Twisted Pear Audio