I bought this board to fit into a mini lathe I bought (which originally had a blown PCB too!)

John S identified this particular board as a potential replacement for the origina (on Ebay- it only cost £15! The board is a Danfoss s100 -often rebadged...varispeed seems to be a constant when rebadged)

I adpated to fit into my Sieg C2 300A ...it's worked fine for about 5-6 months but a couple of nights ago while running at a relative high RPM, a flash eminated from the lathe's control box - fuse blown. Popped in another fuse (not expecting much!)...the motor turned very slow (like 1-2 RPM!) ...and then I smelt that all too familiar smell of some silicon cooking.

For an output stage, the circuit has two TO-220 types with S6060L (SCRs?) & 3 other D6020L (diodes)- no obvious burn marks/melting anywhere, so I'm hopeful it's just a matter of whipping out the larger silicon & finding one that's blown.



Would anyone have a suitable circuit where I could gen up on what the gig is? (not sure if this PWM derived speed control or not?)

At 70 notes for a replacement(& this is the second one that's blown to date on this particular lathe) - this mini lathe pastime is starting to lose it's appel!