Maker Pro
Maker Pro

Magnifying light voltages

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Thanks Bertus. Interesting. The diopter is 125mm dia. They have a 5" one there but no way to guarantee that it will fit. The fit is quite restricted. Before I take that chance I'll rather build something with a bunch of led's
 

Martaine2005

May 12, 2015
4,932
Joined
May 12, 2015
Messages
4,932
Well, interesting results.
One meter giving me DC and the other AC.
R1 330V. 23V.
R2 23V. 7.5V.
D5 23V. 7.5V.
C5 0V 7.2V.
The DC for D5, C5 and R2 was between 2.6VDC and 3.42VDC on the auto range Fluke.
I don’t think I am getting reliable results here. But I won’t lick my finger to check!
These inverters shouldn’t really be powered without a load. So I kept my tests short and sweet.

Martin
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Thanks a mil Martin
That helps a lot. So R1 could be a problem. Colours green/brown/white and gold. That gives me 51MΩ. Correct?
Pretty sure I don't have that in my stash.My one dmm reads 10MΩ but got nothing else to corroberate with
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
On closer investigation green/brown/yellow so 0.51MΩ
 

bertus

Moderator
Nov 8, 2019
3,305
Joined
Nov 8, 2019
Messages
3,305
Hello,

When it is 510 K, an 470 K will likely work.

Bertus
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Thanks Bertus
What I am trying to get around is R1 I assume is there to drop the voltage from 330 V to 23V. In my case it drops the voltage to 137V. So my reasoning says my R1's resistance is too low. But measuring it in circuit it measures about 500k. So why is it not dropping the voltage.Or could C5 be causing the trouble?
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Can you measure a resistors resistance while it is in a powered up circuit?
 

bertus

Moderator
Nov 8, 2019
3,305
Joined
Nov 8, 2019
Messages
3,305
Hello,

I have tried to make a "handdrawn" schematic in Kolourpaint.
Can you fill in some values?

Bushtech_CFL schematic.png

I have used this public domain sheet for the components to copy and paste:
Electrical_symbols_library.png

Bertus
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Bertus
Thats fantastic
But I'm battling to ID the components with any certainty. I have done some updating on this layout. Please can you number the components on your layout as per this sheet. I have highlighted the component numbers

PCB Bottom 71.jpg
I cant ID D5 but it reads 510 in diode mode

My apologies
 

bertus

Moderator
Nov 8, 2019
3,305
Joined
Nov 8, 2019
Messages
3,305
Hello,

You are still missing some parts:
Bushtech PCB Bottom 71_ comment.jpg

Here is what I can see to annotate:

Bushtech_CFL schematic.png
I do not see a R3.

Bertus
 

bertus

Moderator
Nov 8, 2019
3,305
Joined
Nov 8, 2019
Messages
3,305
Hello,

Did you also identify the capacitor between the DB3 and the line 0?
It is a green one on the picture.

Bertus
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Apologies Sir Bertus. Fortunate that I did not take up electronics as a profession:eek:
I hope this works now

PCB Bottom 73.jpg
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
Oh and R4 was actually R3 and the new R4 is to the right and below Q1
 

bertus

Moderator
Nov 8, 2019
3,305
Joined
Nov 8, 2019
Messages
3,305
Hello,

Then this could be the schematic:
Bushtech_CFL schematic2.png
Do you also have some values?

Bertus
 

bushtech

Sep 13, 2016
1,025
Joined
Sep 13, 2016
Messages
1,025
C5 202J 0.002uf ?
D5 ?
C4 220J
C6 104J 0.00022uf
C7 407J ?
D6 & D7 FR107S
 

bertus

Moderator
Nov 8, 2019
3,305
Joined
Nov 8, 2019
Messages
3,305
Hello,

When I look at the schematic I made, it looks a lot like the luxtek 8W, from the site I gave on page 1:
luxtek8w.png
One of the differences is that D2 is not there and there are diodes on the basises of the transistors.

I don't get the value of C7 407j ?, that would be very large.

Bertus
 
Top