[DR-Motion]

"The hobby cnc board is assembled. I had to purchase a 20V AC 10Amp transformer . I am not sure as to where the capacitor fits into the circuit pls help."


Frankly, it scares me when I hear a question like that... from your picture I see a 75WVDC 18000 microfarad capacitor sitting next to a 24V 250 VA transformer... and a "where the capacitor fits into the circuit pls help"

Please take the time to learn a bit about power supplies before you start to play with this "toy" because if you blindly follow directions and hook this to here and this to there as suggested by well meaning helpers... you could be left in a potentially dangerous situation.

For example, suppose you hook up everything correctly... which means the wire from the labelled "+" terminal of your bridge rectifier ( looks like it is hanging off the edge of the table) and the wire from the labelled "-" terminal of the same rectifier are connected to the similarly labelled "=" and "-" terminals on the capacitor. Now you power up the supply ... well if you ( and please DO NOT DO THIS ) were to place a screwdriver across the terminals of the capacitor... it would probably melt in a far too exciting pyrotechnic dislay!

However if you were to unplug your supply and wait ten minutes and then try the screwdriver trick... IT WOULD STILL HAPPEN!

Large capacitors hold a LARGE charge.

To prevent this dangerous situation connect a 1K 2 watt resistor across the terminals (which means connect the plus to the minus with the resistor) of the capacitor. A 1K resistor will consume a mere 24mA and will ensure that the capacitor will discharge safely after the supply is turned off.

Excuse me for being such a worry wart but I'd like to read about your next success will your machine, hopefully typed with both hands intact.

Best regards Gary