Hi All,
Some advice please.
I am making a project for my boat that involves utilising the rudder angle sensor (a potentiometer 3->193 ohm) to drive three(3) X27 168 instrument panel steppers. You may ask, "why 3?". It's because I can drive the boat from 3 positions, and I need to see the rudder angle from each station.
It has been easy enough to set up the workbench model driving a single X27, but my question is as follows.
Driving 3 X27's in parallel is too much current for a single set of pins on an arduino. I could use 12 pins to drive 3 X27's, but, I want to know whether I can use a H-bridge and connect all 3 X27's, or use just 4 arduino pins to drive 3 H-bridges which then drive the X27's etc.
Your advice greatly appreciated
Yes either option would work.
If they are capable of being driven with the current from an Arduino pin then why not just use a transistor to increase the current switching? Can the be driven as unipolar motors or are they bipolar motors? If bipolar then you need a h- bridge.
Hi Mike,
Thanks for your reply. I'd assume they are biploar because gauges go up and down 
. So, H-bridge would be the answer. Because the resistance is only a few ohms on the coil of a stepper, putting 3 in parallel would reduce the resistance accordingly. Would this get too low?
Pete
I'd assume they are biploar because gauges go up and down
No that doesn't make sense. How many wires does each motor have? Four for a bipolar and five or six for a unipolar.
The h-bridges are designed for a large current, typical at least half an amp. As the Arduino can only supply 40mA it is well within the capacity of normal drivers.
(System bombed me out from posting too much within 5 minute period)
Yep, 4 wires.
Here is a link
petere10:
Because the resistance is only a few ohms on the coil of a stepper,
No it is 260R so three in parallel is 65R. That across 5V is only 77mA.
You will not find a h-bridge that can't handle that.
Thanks again for your valuable comments!