K8004 puzzled with diagram

Kits Mini Kits Range
1

I’m diagram from manufacturer PDF file. The areas I do not understand are in red circle.

Also on this site here Circuit Specialists Inc. - DC TO PULSE WIDTH MODULATOR (K8004)
They have part list too.
And they changed the T2 tranzistor from BUK9535-55 to

T2 BUK555’60B LOGIC LEVEL MOSFET 60V (I can order this is it correct and will work as expected?)

It also seems that I can’t get the T1 BC547B SI-NPN 50V-0.2A but instead I can get the BC546B. The pdf (http://www.datasheetcatalog.org/datasheet2/d/0kq9ua20u27ka13c66efh960khpy.pdf) lists them as the same part???

2

Lines are connected.
BUK555’60B will probably work too, but is old and obsolete.
BC546 will work.

3

Thanks, for reply. Are you sure those connections should be made, one would expect a “dot” to show that.

Are you sure BUK555’60B will work?

I can order my part parts from:
Farnell LT | pasaulyje lyderiaujantis elektronikos ir technin?s prie?i?ros, remonto ir valdymo produkt? platintojas.
https://www1.elfa.se/elfa~eu_en/b2b/start.do

Could you help my find better compatible mosfet? They do not list BUK9535-55

4

I am sure they should be connected (you can measure this on the board), however, as I’ve said, BUK555 will probably work. It is up to you to give it a try…

5

I installed BUK555 and connected low power 5w halogen lamp. Everything works except I can’t adjust the output brightness. The voltage changes between GND and IN ports when I turn the 1K ohm POT but output voltage on LOAD ports does not change.

Tried to adjust RV1,2,3 no change. Is there some reference point I could check in this situation to find a faulty part etc. I connected everything like in diagram on PDF.

6

Check if mosfet gate receives PWM.
If not, check assembly (solderings, values, part orientation, etc…)