One of the nice things about the Adafruit perma prota boards is that you can take what is on a breadboard and reproduce as a soldered project.
However when it comes to powering this, you have to solder leds from for example a 9v battery clip to the board, this ends up as a weak point, and can break easiiy
I have now found an excellent and cheap solution.
Solder a 3.5 mm DC barrel socket on to the board.
There are 3 pins on this
One is a tag or lug on the unit the other two are positive and negative, I worked out which was which by plugging in a battery and then putting a multimeter across the pins to work out the voltage across the pins.
It turned out for me the end pin was +ve and the one in the middle was 0v (negative)
However there are several different sockets out there so you need to check this.
This board is now ready for the actual circuit to be added.
The advantage here are that the plugs linked to a 9v battery clip can be connected to different battery arrays e.g
2x 1.5 AA or AAA = 3v
4x 1.5 AA or AAA or 6v
1x PP3 or 9v