I am designing the following circuit for my college quiz club.
I have replaced the bulbs
BL8 with suitable LEDs and resistors.
Now, the issue here is that given a 5V input (from a USB hub), the logic works fine, but the LEDs are very weakly lit and the buzzer doesn't produce any sound. If I power it via a 9V battery, all the LEDs glow brightly and the switches
S8 don't have any effect.
To fix this, I was thinking that the buzzer and the LEDs would need their separate power supply to be activated by some transistor based switch.
Is there any way that can be avoided?
Here is the website I got the circuit from.