dear madk
i have two transformers with rating 18volts/80VA . i want to make an SEWA with lower power rating. i will be happy if i can get a 5 watts power output . shall i lower the bias current, so i can use these transformers. what is your opinion
regards
renjish
i have two transformers with rating 18volts/80VA . i want to make an SEWA with lower power rating. i will be happy if i can get a 5 watts power output . shall i lower the bias current, so i can use these transformers. what is your opinion
regards
renjish
Lower the bias to 1,5A and make shure your transformers have some ventilation 😉 To get 1,5A bias, use R12=0,4ohm. (R12A-E=2R).
I can't understand what's happening. I've double-triple (and more...) checked the PCB in conjuction with the diagram, but nothing found.
V+ = 22,5 V, BUT when I connect it to the SEWA, it falls to 8V!!!
I seen no shortcircuits, no mistakes on the PCB.
PCB= Rev.1
Diagram=Rev.D
Differences=R6(I put 1k, by Rev.D) R2(100K, by Rev.D) R9(100K, by Rev. D)
C7, which I have not put it yet.
Is there something else should change?
V+ = 22,5 V, BUT when I connect it to the SEWA, it falls to 8V!!!
I seen no shortcircuits, no mistakes on the PCB.
PCB= Rev.1
Diagram=Rev.D
Differences=R6(I put 1k, by Rev.D) R2(100K, by Rev.D) R9(100K, by Rev. D)
C7, which I have not put it yet.
Is there something else should change?
Except that it falls from 22.5 to 8 V afteer connection with the supply,
Q1 gets hot while Q2 is cold
Q1 gets hot while Q2 is cold
The transistor IS BC550C. I ve soldered it correctly (the pins I mean). I've checked it a lot of times.
Transformer: !8V, !.4 A.
Transformer: !8V, !.4 A.
Aetosa,
If I got it correctly, you have a 18V, 1.4 A tranny??
That's a problem, you need a much bigger transformer. I am using a 200W transformer for one channel of SEWA.
regards,
Vix
If I got it correctly, you have a 18V, 1.4 A tranny??
That's a problem, you need a much bigger transformer. I am using a 200W transformer for one channel of SEWA.
regards,
Vix
Yes, correct.
Do you think that's the reason it's falling at 8V (from 22.5V) after I connect it to the supply?
Do you think that's the reason it's falling at 8V (from 22.5V) after I connect it to the supply?
Hi,
Yes. The only way for you to find out is to connect a bigger transformer, or, find two 12v car batteries, connect them in series, so you get 24 v and measure.
Yes. The only way for you to find out is to connect a bigger transformer, or, find two 12v car batteries, connect them in series, so you get 24 v and measure.
Chokes question
Hi Choke Masters Circlotron and Fuling!😀
I need your help to make a minimum 120mH 3A chokes!
I found a workshop wher they could make the EI core chokes, but they need the:
- EI core size
- gap distance
- turns number
- wire diameter
I think about a 300VA EI transformator core with 0.25mm gap and ca. 200 turns of 1.5mm2 wire. What do you think?
Could you help me and give some info????
Greets:
Tyimo
Hi Choke Masters Circlotron and Fuling!😀
I need your help to make a minimum 120mH 3A chokes!
I found a workshop wher they could make the EI core chokes, but they need the:
- EI core size
- gap distance
- turns number
- wire diameter
I think about a 300VA EI transformator core with 0.25mm gap and ca. 200 turns of 1.5mm2 wire. What do you think?
Could you help me and give some info????
Greets:
Tyimo
I´m sure it will!
Resistors across the choke (27 ohms or so) might help if you get problems with ringing on the square wave test.
Yes, I have some Rev.C boards available, look here:
http://www.diyaudio.com/forums/showthread.php?postid=989085#post989085
http://www.diyaudio.com/forums/showthread.php?postid=989085#post989085
I will be very happy if i can buy 4 pcb`s
I have no e-mail at home but on my work on monday.
hans-olof@bennstroms.se
Or sms your address on 0703506696.
I send you the money and my address.
I have no e-mail at home but on my work on monday.
hans-olof@bennstroms.se
Or sms your address on 0703506696.
I send you the money and my address.