[sdiy] Op-amp to boost VC signal with +5V/GND?

[Thomas Strathmann]

On 8/23/10 17:58 , Harry Bissell wrote:
> If i need a non-inverting amplifier, I'd use two NPN transistors. The first one can
> have a divider at the base to get any trigger level you want, take to output from the
> collector, then invert with a second NPN. Needs two transistors, four resistors.

Yes, That would have been an option, but in this case I needed two 
non-inverting amplifiers and I would not have saved anything in 
comparison to a four resistors + dual op amp in 8 pin configuration. 
Your suggestion is duly noted however for the future. Thanks!

> You might use an unbuffered CMOS inverter as a linear gain stage, but with no input
> they queue up to 1/2 the supply and usually oscillate there... (nasty)

Hmm, interesting idea, but if oscillations are a problem then I will 
stay away from that particular circuit.

	Thomas