Hi spec,
You make two very good points. I was being lazy. I use the 1N581x series schottky diodes when I build boards with PICs so that the ISCP programming connector does not try to power the rest of the circuit. I have a stock of BC337s so I just picked that number and the P channel MOSFET is a type I had just added to a recent Farnell order to make up the price to get free postage. It looked a useful device. It is an SMD device so that may not suit the OP. There does not seem to be many P channel mosfets with a low RDSON resistance in a TO-92 package.
Hi Les.
I too am lazy.
I often do not bother to read the OP in detail before leaping into a design.
Mind you, some of the OPs are a bit vague/convoluted/convoluted: 'My computer has stopped working. How do I fix it.'
But on the other hand, some OPs couldn't be more definitive and informative.
Yes, you are right, the latest components, with vastly improved performance, are only available in surface mount which is a pain for makers. For example, the ground-breaking OPA192 & OPA197 opamps, are only available in surface mount, and then the most awkward-to-use SM package at that.
It is quite funny how many people in electronics have their favorite go-to components that they tend to keep in their spares box. The BC337/BC327, BC546/BC556, 1N581x & MBR10100, LM358, LM393, LM555 are some of my bits.
One of the electronics magazines had a system where they defined a range of generic functional components: NBJT, PBJT, opamp, etc. and they just referred to the generic part titles on their published schematics. For example a small signal BJT might be referred to as SSNT and an SSNT could be: BC107, BC108, BC109, BC182, BC183, BC184...
As it is a Sunday I thought I would deliver a sermon. I will get my coat now.
spec