0081 - Kit Build: Build and improve an LM317 Based Variable Linear Power supply 

I built the almost exact same kit. I scrapped all the logic probe stuff. I haven't needed a logic probe for decades. When I found out it crow-bared at 150 mA, and the LM317 with a heat sink can sink 1.5 amps, I scrapped the plug and transformer, and in stalled a DC adapter socket. I use an old Laptop power supply that can produce 2 A @ 16 volts DC. It works so well, I actually use it instead of my big bench supply. It weighs nothing, it's easy to move around, and it's good for most stuff I need, and it can sink a fair bit of current for short periods of time before it gets too hot. I like that you added a power switch, and those banana lug terminals. I might just change mine now. Thanks.

Since, as previously mentioned in the comments, the inverter chip takes a lot of power, I added a switch on mine to remove power to it.

Thanks!

Perhaps the mains filter cap can't hold up the rectification above 150mA?

£3.31? This business can't be profitable.