I prefer MosFet transistors to bipolar transistors because of less voltage drop.
The BS170 has an ON-resistance of 1.2Ω at a gate voltage of 10V, resulting in a voltage drop (loss) of 24mV at 20mA, whereas a bipolar transistor normally drops 0.7V.
I prefer MosFet transistors to bipolar transistors because of less voltage drop.
The BS170 has an ON-resistance of 1.2Ω at a gate voltage of 10V, resulting in a voltage drop (loss) of 24mV at 20mA, whereas a bipolar transistor normally drops 0.7V.
No.
An ordinary little transistor like the 2N4401 has a collector saturation voltage of only 0.05V at 20mA, not 0.7V.
Maybe you were thinking of a huge 2N3055 power transistor at 9A.
No.
An ordinary little transistor like the 2N4401 has a collector saturation voltage of only 0.05V at 20mA, not 0.7V.
Maybe you were thinking of a huge 2N3055 power transistor at 9A.
So, 'scuse my ignorance again but, on small circuits with very few 'voltage drop' components, a bipolar transistor would be ok, but when the circuit it large and therefore the total cumulative voltage drop is large, a mosfet is preferable? Is that about right?
wouldn't an ULN2803 be a better choice as far as cost and parts count?
not sure of current capabilities but I recall 500ma?
seeing how the op is fairly new at this using mosfets might be a mistake as static electricity and soldering heat not to mention cost. $1.50+ per mosfet as opposed to $1 for the uln2803 with 8 outputs.