2254C build/support thread

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi Guys,
Sorry my newbie questions :( but I am not sure about CZ
Is that right ?
http://fr.farnell.com/wima/fkp2-10000pf-5-63v/condensateur-10nf-63v/dp/1005977
___

C'15 is 470u 25V but I got 470u 10V
is it ok? or I have to get the same V ?
___
C'7-C"7  just I see 47 ?
C'-C" + C'6 C"6 =80u?
I can't see them on the BOM!



Thanks,
 
Hi, all is here:
http://twin-x.com/groupdiy/thumbnails.php?album=409

CZ: Please take some time to read about Zobel network.
In short, this is resistor+capacitor used to smooth output
transformer's transient response. Depends on transformer used.
I guess 1k5 1/4W metal film for Rz and 4n7...10n poly, 63V, for Cz, 
this is the info I got from guy who built the unit with Carenhills and did some investigation
on Zobel networks.

Capacitors etc P/Nr's: Farnell search.
http://il.farnell.com/jsp/search/browse.jsp?N=500004+1000224+5087689+5400430+5087786+5156429+5117011+565143+565157&Ntk=gensearch_001&Ntt=capacitor+470uf&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_IL&catalogId=&prevNValues=500004+1000224&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D500004%2B1000224%26Ntk%3Dgensearch_001%26Ntt%3Dcapacitor%2B470uf%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_IL%26catalogId%3D%26prevNValues%3D500004%2B1000224

Etc.

C'7-C"7  just I see 47 ?

47uf, 25v

C'-C" + C'6 C"6 =80u?
I can't see them on the BOM!

The BA183 part is copy-pasted from old good drawing, thus, weird values.
Use here 100u 25V axial BC or Philips capacitors, like 1272' guys do :)

http://il.farnell.com/vishay-bc-components/mal203036101e3/capacitor-100uf-25v/dp/1165423

In general:

http://il.farnell.com/jsp/search/browse.jsp?N=500004+1000224+5087689+5400430+5117008&Ntk=gensearch_001&Ntt=capacitor+100uf&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_IL&catalogId=&prevNValues=500004+1000224&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D500004%2B1000224%26Ntk%3Dgensearch_001%26Ntt%3Dcapacitor%2B100uf%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_IL%26catalogId%3D%26prevNValues%3D500004%2B1000224
 
I finished (soldering:) my compressor and I got a problem with the PSU !

I don't have 24V on the PSU-> PSU in 30 V and PSU Out 30V!!

I put a trim(R 3 -5K) and also I did't understand for 3k57!!! what is does ??

I have  no idea for this problem I have searched it but I didn't find. if any b'dy had the same problem please  explain !! What I need to do??

Thanks,
cheers,

 
R3 or R5 (in combination with the R1) select the output voltage of the power supply. look up the LM317 datasheet for more info as to how this circuit works.

you only need to fit one of the following:

5k trim pot (R3)

OR

3k57 (R5)

if you have installed the trim pot, before connecting the power supply to the main board, adjust the output voltage to 24v using the trim pot. if you have installed R5 you should have roughly 24v straight away.

as with any project, you should always check the power supply first with your multimeter before connecting it to the main board - if the voltage is reversed or too high you can damage many of the components! however, in this case 30v shouldn't have hurt too much.
 
haima said:
R3 or R5 (in combination with the R1) select the output voltage of the power supply. look up the LM317 datasheet for more info as to how this circuit works.

you only need to fit one of the following:

5k trim pot (R3)

OR

3k57 (R5)

if you have installed the trim pot, before connecting the power supply to the main board, adjust the output voltage to 24v using the trim pot. if you have installed R5 you should have roughly 24v straight away.

as with any project, you should always check the power supply first with your multimeter before connecting it to the main board - if the voltage is reversed or too high you can damage many of the components! however, in this case 30v shouldn't have hurt too much.

Thanks Haima,
I got a mistake I have put 10K not 5K :( sorry !
is it ok ? 10K ? ( like R6 10 k 67w)
Cheers,
 
you have put a 10k trim pot instead of a 5k into R3? and you haven't installed R5?

you might be ok with the 10k - if you can adjust it to 24v you should be fine... can you adjust it to 24v?
 
haima said:
you have put a 10k trim pot instead of a 5k into R3? and you haven't installed R5?

you might be ok with the 10k - if you can adjust it to 24v you should be fine... can you adjust it to 24v?

I got two trim pots now -->R 5 and R 3 = 10K
I turn the trim but I have no change on multimeter
but now I got 34V:( I counted the diodes and they work! LM 371 is fine too. I can't understand where I had a mistake?
Thanks ,
Cheers,
 
you should have one trim pot installed in the R3 position and nothing installed in the R5 position.

what do you mean by "I got two trim pots now"?

there is a place for another trim pot on the board (R6) - in the "for adjustment only" section of the board - but this is not needed as far as i know.

what is the voltage at the input pin of the LM317?

 
haima said:
you should have one trim pot installed in the R3 position and nothing installed in the R5 position.



what do you mean by "I got two trim pots now"?

what is the voltage at the input pin of the LM317?

I got two trim pots ->R6 10k and R3 10K

LM317;
* -95,4 mV
* -95,4mV
*  0


 
jandoste said:
I got two trim pots ->R6 10k and R3 10K

ok. and nothing installed in R5?


jandoste said:
LM317;
* -95,4 mV
* -95,4mV
*  0

that doesn't sound right...

are you measuring DC voltage? you should have your common/black lead attached to the "-24v" point on the bottom right of the power supply PCB.

are you sure you haven't pressed the hold button on your multimeter?

LM317.jpg


you should have 30v+ on the "V in" pin and a the same or lower voltage (depending on the trim pot setting) on the "V out" pin.

what's the voltage across the big capacitor C1?


 
haima said:
jandoste said:
I got two trim pots ->R6 10k and R3 10K

[quote ok. and nothing installed in R5?
Yep, there is nothing.


jandoste said:
LM317;
* -95,4 mV
* -95,4mV
*  0

that doesn't sound right...

are you measuring DC voltage? you should have your common/black lead attached to the "-24v" point on the bottom right of the power supply PCB.

You were right I got the same value  : 30V

are you sure you haven't pressed the hold button on your multimeter?


Yes, it was sorry ,


you should have 30v+ on the "V in" pin and a the same or lower voltage (depending on the trim pot setting) on the "V out" pin.


same 30V

what's the voltage across the big capacitor C1?

30V

Thanks for helping man!


 
great. seems like everything is correct...

so, are you able to trim the output to 24v by turning R3? it might take quite a few turns if it's a "20 turn" type.
 
double check every single component....
connect 24V to ur PCB... and fire,
hope you dont smoke  ;D

re check ur 24V... adjust if necessary...
check if audio passing ok... check controls are working...
then calibrate
 
Back
Top