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 …

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.