Building a symmetrical psu B1 buffer

[AndrewT]

Originally Posted by grufti

Try it with two BC550. My prototype Mez worked just fine with 12V relais and two BC550C.

You can always find and substitute a Darlington, if it doesn't work. The proto builders who ran into trouble heard "chatter" from the relay.

I still think this chatter problem is not what you think it is.

I still believe you have suggested the wrong solution.
I await my boards and will experiment to try to replicate the "fault". I bet an extra capacitor will solve the imagined problem. There is space on the PCB for it. Just to the left of the resistor labeled "note". The extra cap will fit across the left end of the same "note resistor" and the -ve of the 100uF capacitor.
Add it to your schematic of the Hypnotize and you'll see I have referred to this cap in this and other threads.

[Salas]

Originally Posted by Ryssen

Does there have to be a darlington transistor or can it be substituded with ex.BC550?(Don´t have any at home...)

If you get problems, its either addressed by the 100-150nF comp cap across c,b of the relay coil sink transistor, or use BC517.

[Salas]

Originally Posted by manollo

Hi salas
I live also in Greece and I have some questions for your project
Can you email me at *****?
Thanks
manolis

Read the forums, ask here. There are 602 first round boards out there, you don't want me to have people telling me I give personal guidance and why not to all. I must be fair. Cheers.

P.S. No full emails online, there are spam mailbots scanning the web. Therefore I will take out yours, not to be exposed.

[Salas]

Originally Posted by AndrewT

I still think this chatter problem is not what you think it is.

I think its due to marginal current gain of the coil NPN Andrew. Thus the 517 worked. But then again not sure, bcs I never got it in my build so to research.

[tinitus]

These sweet cuties arrived today

[Salas]

We will see some build from you soon I presume.

[tinitus]

I will certainly try

Someone talked about making some kind of assembling manual

I dont know, would it be possible to collect all the most important information/posts in some kind of file
Maybe not all at once, just bit by bit
Well, maybe I should just start reading thread again

[Salas]

Building a symmetrical psu B1 buffer

[tinitus]

Ahh, thats nice
I remember the posts, but must have missed it was about the build guide

[MashBill]

How many LEDs should I buy to get 2 matched strings of 8? More than 20? 30?