[Alt-photo] 365 nm. UV-Densitometer. Part 1b of 7

[Erich Camerling]

The power supply  (part 2)

The wiring diagram must be clear : from the -5 V , the +5 V and the +10 
V power supply the "earth " is executed as "sense " connection.
In that manner the issued voltage is independent from the alternating 
voltage drop (by <= 500 mA pulses through the UV-LED) over the supply wires.

Connections:
I am using Combicon industrial screw terminals for printmontage from 
Phoenix Contact , type MKDSN , PCB terminal block.
That was the cheapest solution for me.
You need  4 (green) screw terminal blocks with each 3 connectors (terminals)
X1-1 : alternating voltage from the trafo
X1-2 : alternating voltage from the trafo
X1-3 : middle branch of trafo ( 0 Volt)

X2-1 :   - 5  V  (stabilized)
X2-2 :  - 14 V
X2-3 : sense - 5 V (connect to 0 V)

X3-1 : 0 Volt
X3-2 :  + 14 V
X3-3 : sense 10 V (connect to 0 V)

X4-1:;  + 10 V  (stabilized)
X4-2 : sense + 5 V (connected to 0 V)
X4-3 : + 5 V  (stabilized)

The trafo you need has sec.2 x 12 V (and middle branch.) with a power 
of  5 VA.
(Dealers : newark,farnell,mouser,digikey (conrad, dickbest for the dutch))
I bought a WEISS trafo type EI 42/14,8      5 VA , 2 x 12 V  (for me the 
cheapest)  but every other mark is okay.

to be continued next week