I have a dim memory of running into something called an IRF640A that turned out to not be suitable for use in the clock circuit. Aside from that "A" the suffix letters shouldn't matter. Just make sure to select one that's in a TO-220 package. If ordering from a major distributor (Mouser, CPC-Farnell, etc.) the package style should be clearly stated in the part description.
Ordering a few spare inductors (150uH, >=2 amp) is a good idea and they're pretty much "penny parts". There have been a few forum threads lately about inductor failures, leading me to believe there might have been a defective batch that slipped thru.
Look into it later when the dust is clearing off the crater.
What other factors do I need to look for another inductor?
The one in the HV circuit is 100uH, but I don't know what else to look for. You mention something at least 2amps above, tolerances or anything?
Is there a particular type of inductor this is?
Any suggestions here?
I really am lost when it comes to inductors - I dont have any knowledge of them.
Does anyone have any links at all to what I would need?
From what I can tell, the big one was 100uH, however Ty is suggesting a 150uH?
You said you are in NZ whereas I'm in America. I can't imagine you want to import your inductors from half a world away, so my sources would be useless to you. I was really hoping someone from NZ or Oz was lurking and would offer up a local source.
Here is my pick of inductor from a source in my country. Kemet is a pretty big brand so probably your sources stock their products.
The build that never ends...
I ordered another clock kit from Ian, to replace the first one I built - as it had all sorts of problems that I wanted to fix - mainly my terrible soldering.
It has just arrived, and I note that the resistors are tiny compared to the first kit - the kit is exactly the same Rev6 as before - the body of the resistors is about half the length of the original ones, and all up about quarter the volume.
The original ones were almost the same size as the diodes.
Will this matter? I assume this is power rating, and its ability to dissipate heat? Of the 6 values of resistors in the kit, four are tiny (3k, 1k, 10k, 270k) the two larger types that are the same size as the old ones are (390k, 4.7k).
I guess I just want to make sure these are the right size and safe, as they are much smaller than the last build.