I'm building a 7V SSR01 using a 9V AC supply, which when rectified and accounting for losses should give nearly 12V output, which should be ok with the SSR01 with AD825 I hope. The PCB will be partly visible through a perforated cardboard inside an old tube radio, and would like avoid any shining LEDs if possible.
Would it thus be possible just to use a 2.4V zener diode instead of H1, and just leave R3 at 2.2k? Or is the base current of the BC556B negatively affected by this (as I-V characteristics of zeners and LEDs are not the same) Or would it be possible to even use a 3.3V zener like used as DZ1, possibly lowering the value of R3?
Last post by chinook9 - February 27, 2019, 05:58:04 PM
I have been enjoying my QRV-08 for a long time now but I still have not finished enclosure installation with power LED. I have been afraid of damaging something if I mess up the LED wiring. I understand very little electronics and would not be able troubleshoot if I cause a problem.
I understand how to measure the LEDs I have and calculate the required resistor, however I have not found a specific location on the PCB that I like for the connection.
My friend Keith connected a 1000 ohm resistor to the + side of G31 but I am not comfortable with this location. it is 25V which requires a larger resistor (1500 ohm 2 Watts) and the way I have G31 soldered I have very little space.
Is there a spot you could suggest that would provide 15V and possible is a through the board hole that would be easier to make a good and safe connection.