Author Options:

Best MOSFET for a sstc? Answered

Which MOSFET is best for a sstc in the circuit given? If the input voltage is 140-220v. And is the diode(MUR1560) near the MOSFET(D4 & D5) necessary? Is there any way to exclude that?, By using any other MOSFET?Any MOSFETs with in build diode, so that i wouldn't have to put an external diode? or could a simple in4007 work in place of it? Any other diodes which are more easy to obtain?


The bridge rectifier or 4 diodes configured as an bridge rectifier are required for this circuit. The transformer is taking the 220VAC and dropping it to a lower voltage but it's still AC. The rectifier takes that lower AC voltage and converts it to DC which the rest of the circuit needs.

All the components in the circuit are needed. Take any out and it will not perform as it was designed too. If you are having trouble finding the MOSFETs then pull up the data sheet for those and find another MOSFET with nearly identical stats.

Sorry if i misled you, i was asking about the diodes near the MOSFETs(MUR1560s-D4 & D5),
could a couple of diodes in parallel do any good?

At best diodes in parallel will increase the current carrying capacity through that junction. Not that it would help or hinder the circuit.

so could some 1n4007s be used in parallel instead of the mur1560 diodes?

Check the specs. If the 4007, if it doesn't meet or exceed the specs of the original then it won't work. I.E. it needs to be able to handle the voltages and current.

1n4007 has a forward current of 1A,and MUR1560 has a forward current of 15A, So for the 1n4007s to work should i connect 15 of them in parallel?

Yes you could do that. Why are you trying to use a different diode?

Makes for quite a crowded board. Not to mention using 15 4007's will cost you about 30% more then a single 1560. It will also be easier to attach a heat sync to the 1560 since it comes in a TO-220 package. 



I live in India and it is hard to find MUR1560s and even if i order it online it would cost me more. Beside, I'm not allowed to order online. Since 1n4007s are in every appliances these days it is easy to salvage many of them. Also thanks for the help.