Electronics > Beginners

LTspice help - transformerless power supply simulation



I'm new to LTspice simulations and I would like to construct the following "Capacitive Transformerless Power Supply - App. Note here", but when I run the simulation, I get on net1 the same voltage of V1 and not something like 5 VDC. What am I doing wrong?

Thanks in advance and Long Live David Jones

Here follows my LTspice file.

If you move the ground node to the same location as in the appnote, or plot V(net1) - V(n003), you'll see the results you'd expect: the zener voltage minus the drop over D2.

If you want to build this, you must consider the whole circuit as dangerous mains, since the caps provide no galvanic isolation, and are probably not rated for line filters (X/Y), so they may be destroyed (or fail shorted) by transients.

Thank you very much alm! It worked!

Thank you too for warning me about the risks, as says the Microchip Application Note, I'll use a fuse and other security considerations when I build it.

There needs to be a bleeder resistor (about 1M) across C1 to prevent someone from getting a shock when the plug is removed.

What's the supply voltage? LTSpice uses the peak voltage so 110V is only equivalent to 78V RMS, you need to enter 155.6V for 110VAC.


[0] Message Index

There was an error while thanking
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod