I built a dark circuit - “Dunkelschaltung” which should light a LED on 9V when it is dark.
I used a BC547 Transistor and some resistors. 1k on the Base and 1x 100k for sensitivity of the circuit.
Everything went fine. When the LDR was covered the LED turned on.
NOW I wanted to replace the single led with a parralell array, of about 30 leds. (4 Leds serial and those series parallel)
This array is already built and works perfectly with 9V.
I measured voltage between + and the collector of my BC547 (where the LED is connected) … correct 9V. (when LDR is covered - 0 if its in light)
But if I remove the single LED and replace it with the connection wires of my array nothing happens… the array does not light up even if I use an external power supply instead of the battery.
What am I doing wrong?
Answers german or english