2019年9月6日 · 1/4w resistors will probably be cheaper, and use less surface on a circuit board. Also, there's surface mount 0805 resistors which are rated for 0.1w and can be more convenient to use (for example value printed on them, big enough to solder by hand on pads, just the right size to fit between two through holes 0.1" apart, so great to use on prototyping boards) ^ The above are 1206, pins are 0.1 ...

2019年11月29日 · You nearly have what's called a Vbe multiplier circuit: in the both-switches-on state, Q3 should be well saturated, and Q4's collector voltage is set by R4-R6, less Q2 Vbe.