I am attempting to follow the fade circuit schematic, and when I power on, the LED turns on without the need for the tactile switch. I am not catching where I have incorrectly wired the circuit. Could someone please point out where I went wrong?
Sure! I’ve had a look at the image and I can spot one major issue – the way the tactile switch has been wired. The switch has 4 pins but two pairs of pins are internally connected together. You’ve used a set of pins which are connected internally and this means that the switch is always ON, as far as the circuit is concerned. Please check the layout diagram and move one wire to either of the terminals on the left (towards the battery pack).
Also, I’m not sure how R3 is connected, as the image is not very clear. Make sure it is wired between the negative terminal of the power supply and the capacitor (positive terminal). Rest of the connections look good from here.