Hey guys, trying to design a circuit that uses 555IC to time a DC motor.
the motor is drawing about 3A at 9.6V.
Initially was using darlington transistors but that failed miserably and it was suggested i try using Mosfet
With a little investigation i've read that mosfets require about 10x the gate voltage compared to the source/drain? is this true? If so how would i possibly run my motor on the 9.6V battery alone??? would i not need approx 96 volts through the gate in that case?!?!
if im completely wrong and you know of any mosfets that would suit my problem i'd very much appreciate a suggestion.
thanks for any assistance you can provide
With a little investigation i've read that mosfets require about 10x the gate voltage compared to the source/drain? is this true? If so how would i possibly run my motor on the 9.6V battery alone??? would i not need approx 96 volts through the gate in that case?!?!
sorry cant find it again, i was thinking maybe a TO-220. i have a jaycar just around the street so supply should be quite easy. Any suggestions would be most appreciated
Just had a quick look at jaycar (australia), not sure of your location - they have a BUZ71 for $4.95 which will work. Seems a little expensive (and it's not a great fet, it does have a large RDSon), if you purchase from Farnell / Element14 you can get suitable FETs for probably 50c (but $10 min order).
Did you ever mention what frequency the 555 is operating at?
using the 555 as a timer rather than oscillator. Basically using the circuit to control a lead screw extension, e.g. 2sec ---> actuator extends, with an H bridge do the process can be reversed. Just been teaching myself the basics of electronics for projects/ interest so forgive my ignorance
Oh, OK. I just assumed there may be some PWM or something for speed control; there's no problem with switching frequency then... It should all be fine.