Rank: Member
Groups: Member
Joined: 11/13/2008(UTC)
Posts: 36
Location: NJ
|
After assembling a placid 2.01 VR2 won't adjust voltage past 3.99 Vdc. Transformer is 9 Vac VR1 adjusted curruent to 350 mA.
I can adjust voltage down, just not up past 3.99, what should I check. I suspect I may have a cold solder joint at VR2, would that do it?
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 6/17/2008(UTC) Posts: 921  Thanks: 1 times
Was thanked: 70 time(s) in 69 post(s)
|
Pictures please, top and bottom.
|
|
|
|
|
|
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)
|
Top reasons for this:
- Misplaced transistor. Double-, then Triple-check the NPNs and PNPs are where they are supposed to be.
- D1 is backwards.
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 11/13/2008(UTC)
Posts: 36
Location: NJ
|
Will do... Thanks Brian. I'll post pics if that's not the case
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 11/13/2008(UTC)
Posts: 36
Location: NJ
|
If D1 lights up it's not backwards correct?
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 11/13/2008(UTC)
Posts: 36
Location: NJ
|
I figured it out. All transistors and diodes were correct. It turned out to be user error! Voltage across R8 was 0 adjusted it to 0.300 and got the right output voltage.
I lifted the pads for VR2 while removing it thinking that was the initial problem. I put a 3.2K ohm 1/4W metal film resistor in R2 and now I get a rock solid 5.6 Vdc
It's amazing what happens when you double check the simple stuff!
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 6/17/2008(UTC) Posts: 921 Thanks: 1 times
Was thanked: 70 time(s) in 69 post(s)
|
What will it be used for?
Anything involving the old (the first) Trident(s) 5.6v is a little to the high side.
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 11/13/2008(UTC)
Posts: 36
Location: NJ
|
Originally Posted by: avr300  What will it be used for?
Anything involving the old (the first) Trident(s) 5.6v is a little to the high side. only a teleporter. That should be ok right?
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 6/17/2008(UTC) Posts: 921 Thanks: 1 times
Was thanked: 70 time(s) in 69 post(s)
|
|
|
|
|
|
|
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.
